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Publisher: Wiley
Date: 24-04-2015
Publisher: Informa UK Limited
Date: 02-2007
DOI: 10.1080/00480169.2007.36734
Abstract: To assess the ability of two commercial bovine viral diarrhoea (BVD) virus (BVDV) antigen-capture enzyme-linked immunosorbent assays (ELISAs) to detect virus in serum and skin biopsies. Thirty cattle persistently infected (PI) with BVDV were identified using routine diagnostic laboratory testing. Additional ear-notch skin biopsies and blood s les were collected from these animals to confirm the diagnosis, and from 246 cohorts, to determine their BVDV status. Skin biopsies were soaked overnight in buffer and the eluate collected. All sera and eluate were tested using two commercially available ELISAs for detecting BVDV antigen, and a subs le of positive and negative sera was tested using a polymerase chain reaction (PCR) test. A study was also performed to ascertain the risk of cross contamination occurring during the collection and processing of skin biopsies. Both serum and skin s les tested using either ELISA resulted in the detection of all cattle identified as PI and no non-infected cattle were incorrectly classified as infected using either method. Agreement between all assays (ELISAs, whether performed on serum or skin, and PCR) was 100%. No cross-contamination of skin s les between animals was evident using routine biopsy methods. Viraemic cattle infected with BVDV were accurately identified using either of the two commercial ELISAs evaluated on either serum or skin s les. Either skin biopsies or serum s les can be collected from cattle to determine their BVDV status. This should overcome problems in accurately identifying the infection status of young calves in which colostral antibodies might interfere with the antigen-capture ELISA.
Publisher: Elsevier BV
Date: 08-2002
DOI: 10.1016/S0304-4017(02)00086-9
Abstract: To analyse the performance characteristics (sensitivity/specificity) of two enzyme-linked immunosorbent assays (ELISA) against the indirect fluorescent antibody test (IFAT). A total of 1199 sera were tested in two ELISAs and the IFAT and results analysed utilising software that performed a receiver-operating characteristic (ROC) analysis. Sensitivity and specificity for the two ELISAs were calculated for a range of different cut-offs. Minimal misclassification was achieved at cut-offs that, in the case of the Central Animal Health Laboratory (CAHL)-ELISA were in line with previously published cut-off values. In the case of the IDEXX-ELISA lower cut-off values than suggested by the manufacturer were calculated. ROC-analysis resulted in optimised, as compared to the IFAT, cut-off thresholds for the CAHL and IDEXX-ELISA which can be further adjusted depending on the purpose of the investigation.
Publisher: American Society for Microbiology
Date: 03-2007
DOI: 10.1128/IAI.00777-06
Abstract: Neospora caninum is an obligate intracellular protozoan parasite that causes abortion in cattle. It is normally found as a latent infection controlled by a T-helper-cell type 1 response involving CD4 + cytotoxic T cells and gamma interferon. Cattle may be infected by two different routes: transplacentally as a result of activation of the latent infection in the mother causing congenital infection or abortion and by ingestion of oocysts, which, if it occurs during gestation, can also result in abortion. Here, for the first time, we establish proof that live vaccination protects against fetal death, whereas immunization using whole-tachyzoite lysate in different adjuvants fails to protect against fetal death. Strong antibody responses were induced in all the vaccinated groups, and the quality and magnitude of these responses were similar in the live- and the lysate-vaccinated groups. In contrast, only the group immunized with live tachyzoites had strong cellular and gamma interferon responses prior to challenge, and these responses correlated with protection against fetopathy. These results suggest that a cellular immune response may be important in the mechanisms involved in protection against N. caninum -associated abortions.
Publisher: Elsevier BV
Date: 11-2006
DOI: 10.1016/J.VETPAR.2006.06.019
Abstract: To determine the performance characteristics of an Institut Pourquier (IP) enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies against Neospora caninum in bovine milk and subsequent determination of the prevalence of N. caninum infection in New South Wales (NSW) dairy cattle. Matching serum and milk s les from 93 cattle were assayed in two commercially available ELISAs for the detection of anti-N. caninum antibodies. Serum test results of one ELISA (IDEXX) were used to determine the N. caninum infection status of the cattle. Optimised cut-off values for the IP ELISA using milk s les were determined by two-graph receiver operating characteristic (TG-ROC) analysis and then applied to a representative s le of 398 milk s les from dairy herds around NSW. When this ELISA was applied to a representative collection of 398 milk s les from dairy cattle across NSW it demonstrated a 21.1% prevalence of N. caninum infection in those cattle. From the TG-ROC analysis an IP ELISA protocol was derived which suggested a cut-off threshold that would allow milk testing with 97% sensitivity and specificity, respectively, relative to serum testing. The prevalence of N. caninum in NSW dairy cattle was higher than previously believed. When used on in idual milk s les this ELISA demonstrated high sensitivity and specificity and so could be used to accurately identify N. caninum infection. TG-ROC analysis of the IP ELISA optimised the protocol and prescribed cut-off values enabling the ELISA to be used for the screening of N. caninum antibodies in the milk of dairy cattle.
Publisher: Wiley
Date: 05-2015
DOI: 10.1111/AVJ.12316
Abstract: We aimed to establish the attitudes of South Australian cattle farmers towards endemic animal disease prevention and control, with a particular focus on the awareness of and attitudes towards bovine viral diarrhoea (BVD). This cross-sectional postal survey involved mailing a questionnaire to all South Australian cattle owners with 35 or more head of cattle. Worms and lice were the most common animal disease concerns. Less than half of responding farmers were adequately vaccinating their herds against clostridial diseases, but 53.0% stated that they utilised quarantine procedures. Less than 20% of respondents had actively taken part in BVD educational opportunities, or had vaccinated or tested their herd for BVD less than 20% of respondents were actively involved in any systematic control of Johne's disease. Overall, farmers' actual knowledge of BVD was lower than their perceived understanding, although their interest in BVD and its control was high. Disease prevention measures such as vaccination, quarantine and participation in systematic control schemes were used by a minority of respondents. The results suggest that respondents acknowledge BVD as an important and relevant disease, despite many believing it was not a problem in their herd. Interest in BVD appears to be high and it is likely that an education program would be well received.
Publisher: Informa UK Limited
Date: 02-1998
Publisher: Cambridge University Press (CUP)
Date: 09-2020
DOI: 10.1017/S0031182020001596
Abstract: Bibliometric methods were used to analyse the major research trends, themes and topics over the last 30 years in the parasitology discipline. The tools used were SciMAT, VOSviewer and SWIFT-Review in conjunction with the parasitology literature contained in the MEDLINE, Web of Science, Scopus and Dimensions databases. The analyses show that the major research themes are dynamic and continually changing with time, although some themes identified based on keywords such as malaria, nematode, epidemiology and phylogeny are consistently referenced over time. We note the major impact of countries like Brazil has had on the literature of parasitology research. The increase in recent times of research productivity on ‘antiparasitics’ is discussed, as well as the change in emphasis on different antiparasitic drugs and insecticides over time. In summary, innovation in parasitology is global, extensive, multidisciplinary, constantly evolving and closely aligned with the availability of technology.
Publisher: Informa UK Limited
Date: 06-2002
DOI: 10.1080/00480169.2002.36288
Abstract: This article reviews control options for Neospora caninum infection and abortion in cattle, drawing on published literature and the authors' own research in this field. Apart from the successful use of embryo transfer to prevent congenital infection in calves born to infected cows, there are currently no accepted control methods for the prevention of abortions in cattle. The epidemiological data at hand suggest that concomitant infections with bovine pestivirus increase the risk of abortion significantly and that these infections, for which effective vaccines exist, should therefore be controlled. While vertical transmission appears to be the major route of infection in cattle, there is also a role for postnatal transmission, involving a definitive host. Presently, the control of dogs and their access to bovine tissues, particularly potentially infected placentae and other foetal tissues, appear to be the most prudent control methods. There are some indications that vaccination against N. caninum may aid in the prevention of abortions. Suggestions for control options are limited by our current lack of actual experiences with control strategies. Further practical fieldwork is needed in this area.
Publisher: Wiley
Date: 26-07-2018
DOI: 10.1111/AVJ.12709
Abstract: Bovine viral diarrhoea virus (BVDV) and border disease virus (BDV) are of the genus Pestivirus. They are known to cause significant reproductive and production losses, with BVDV acknowledged as a major source of economic loss to the Australian cattle industry. Very little is currently known about the prevalence and effect of pestiviruses in the Australian sheep industry. The present study aimed to examine the seroprevalence and effect of both BVDV and BDV in South Australian sheep flocks. In total, 875 breeding ewes on 29 properties were serologically tested by ELISA, AGID and VNT assays for the presence of Pestivirus-specific antibodies. Three (0.34%) in idual animals returned serological results suggestive of previous BDV infection. All three positive animals were collected from one property, giving a property level seroprevalence of 3.45% and a within-flock seroprevalence of 10%. The results suggested that BDV infection is present, albeit at a very low incidence, in the South Australian sheep flock and BVDV infection appears to be absent. Consequently, pestiviruses are unlikely to impair production in South Australian sheep populations.
Publisher: Elsevier BV
Date: 10-1997
DOI: 10.1016/S0378-1135(97)00110-7
Abstract: The course of immunological reaction in 10 Yersinia enterocolitica 0:9 experimentally-infected heifers was followed using the conventional brucellosis tests complement fixation test (CFT), serum agglutination test (SAT) and brucella card test (BCT), and a recently developed Brucella antigen-specific gamma interferon (IFN-gamma) test. Initially, the animals were exposed orally to 10(10) colony-forming units (CFU) of Y. enterocolitica 0:9. Four weeks later, they were inoculated intravenously with 10(8) CFU of Y. enterocolitica 0:9 cells. After oral inoculation, the response in the conventional brucellosis tests was minimal. Only after intravenous inoculation were CFT and SAT titres and BCT reactions comparable to natural, false positive brucellosis reactors. After oral exposure the Brucellergen-stimulated release of IFN-gamma peaked at values above the cut-off stimulation index of 2.5 in 80% of the heifers. After intravenous inoculation, stimulation indices above 2.5 were present in only 10% of the animals. Two B. abortus infected control cattle showed stimulation indices of 3.1 and 3.4, and a negative control animal exhibited a stimulation index of 1.0. These findings show, in contrast to a previous study, that the Brucellergen-specific IFN-gamma assay cannot be used as a specific and discriminatory test for B. abortus infections.
Publisher: Elsevier BV
Date: 2020
DOI: 10.1016/J.VETPAR.2019.108967
Abstract: Neospora caninum infection is regarded as one of the most important infectious causes of abortion in dairy cattle. To intervene in its spread, four potential controls including test-and-cull, medication, vaccination, and selective breeding are considered and assessed in this study. The cost of each control, together with the inevitable annual loss due to population dynamics, is adopted as an assessment criterion from an economic point of view. By performing simulation and sensitivity analysis, our results demonstrate that compared with each single control, combined controls are worthwhile with better financial outcomes. For farm affected with significant prevalence (equal to or greater than 30%), vaccine treatment is the most effective and economical option among all control strategies. On the other hand, for farm where prevalence is relatively low (around 10%), combined control, by applying vaccination followed with test-and-cull, medication or selective breeding, could be alternative treatment to provide better financial outcome against single control in an observed period.
Publisher: MDPI AG
Date: 23-06-2020
Abstract: Background: Neospora caninum has been recognised world-wide, first as a disease of dogs, then as an important cause of abortions in cattle for the past thirty years. Over that time period, there have been improvements in the diagnosis of infection and abortion, new tests have been developed and validated, and it is timely to review progress to date. Methods: Bibliometric methods were used to identify major trends and research topics present in the published literature on N. caninum. The tools used were SWIFT-Review, VOSviewer and SciMAT, along with the published papers found in the MEDLINE, Dimensions and Web of Science databases. A systematic review of the published Neospora literature (n = 2933) was also carried out via MEDLINE and systematically appraised for publications relevant to the pathogenesis, pathology and diagnosis of Neospora abortions. Results: A total of 92 publications were included in the final analysis and grouped into four main time periods. In these four different time periods, the main research themes were “dogs”, “abortion”, “seroprevalence” and “infection”. Diagnostics, including PCR, dominated the first two time periods, with an increased focus on transmission and abortions, and its risk factors in cattle. Conclusions: Longitudinal analyses indicated that the main themes were consistently investigated over the last 30 years through a wide range of studies, with evolving emphasis initially on dogs and diagnostic test development, followed by application to cattle, the identification of the risk factors leading to abortion, and in the latter time periods, an understanding of the immunity and a search for vaccines.
Publisher: Informa UK Limited
Date: 02-1998
DOI: 10.1080/00480169.1998.36046
Abstract: To describe the kinetics of serological titres after an abortion outbreak in April-May 1995 due to Neospora caninum affected 17 dairy cows in a herd of 320. Thirty-five cows, that had either aborted, carried mummified calves, were not pregnant or calved normally were: bled several times at regular intervals and the sera tested for Neospora antibodies in the indirect fluorescence antibody test (IFAT). Maximal IFAT titres of up to 1:4000 occurred within 6 weeks of the abortion outbreak, decreased over the next 2 months to < or = 1:200 and remained at this level until the next scheduled bleed a further 2 months later. A rise in titres was subsequently observed in the cows that had aborted or were not pregnant (at the time of the abortions) or had carried mummified foetuses. Seroconversion was also observed in some of the control cows, which had, up until then, remained seronegative. A dog and cat in contact with the cows in the herd investigated were, however, negative in the IFAT. Maximal serological titres in Neospora abortions are observed within weeks of the abortion event and then quickly return to very low levels. Subsequently, a recrudescence of titres can be observed in infected cows during the next pregnancy, without it being associated with repeat abortions.
Publisher: No publisher found
Date: 1991
DOI: 10.1016/0168-1605(91)90034-M
Abstract: The hygienic performance of a commercial hot boning process for beef carcasses was assessed by a temperature function integration technique. The potential proliferation of Escherichia coli was calculated from 50 temperature histories for the persistently warmest, microbially contaminated regions of product passing through both the carcass cutting and carton cooling phases of the process. The maximum calculated proliferation was similar to, but the average proliferation was more than, the respective values previously obtained for a beef side cooling process that complied with Good Manufacturing Practice. After upgrading of the carton cooling facility the process was re-assessed. Then, for a s le of 50 temperature histories, the maximum proliferation was less than, and the average proliferation was similar to, the respective values for the side cooling process. Observed proliferations of E. coli inocula in cooling cartons of product were compared with the proliferations calculated from temperature histories obtained from sites close to inocula. The pairs of calculated and observed values mostly agree within +/- 1 generation.
Publisher: Informa UK Limited
Date: 02-1998
DOI: 10.1080/00480169.1998.36047
Abstract: Recently the first case of natural infection of deer with Brucella ovis was discovered. The aim of this study was to develop and evaluate an electrophoretic immunoblotting method for testing deer serum for specific B. ovis antibodies. An existing immunoblotting method for sheep serum was altered by using a recombinant protein G-alkaline phosphatase conjugate and Tris-buffered saline containing 3% non-fat dry milk powder for the blocking step and the serum and conjugate dilutions. The method was evaluated using 106 sheep sera from B. ovis - negative, accredited flocks, 69 sera from chronically infected rams shedding B. ovis in their semen, 110 sera from a B. ovis-infected flock, 18 sera from stags from which B. ovis was isolated, and 48 sera from deer flocks free from B. ovis infections. The immunoblotting method was applied to another 85 deer sera. The sensitivity of the new immunoblotting method was 98.6% for sheep and 94.4% for deer, and the specificity 99.1% for sheep and 100% for deer. Sixty-nine out of 97 deer sera, originating from the property from which the first B. ovis deer case had been reported, tested positive or suspicious in the complement fixation test. Of these, 53 sera exhibited staining patterns in blots typical for B. ovis infections and also one serum which was negative in the CFT. Only six out of 1498 deer sera. from throughout New Zealand had positive or suspicious reactions in the B. ovis complement fixation test. Of these, one exhibited a staining pattern in the blot suggestive of a B. ovis infection, while four showed patterns of suspicious reactions. The new immunoblotting technique is useful as a confirmatory serological test method for B. ovis infections in deer.
Publisher: Elsevier BV
Date: 12-2002
DOI: 10.1016/S0304-4017(02)00308-4
Abstract: The aim of this study was to develop an immunological method for the identification of sheep infected with Echinococcus granulosus which would allow the monitoring of animals imported into countries free from hydatidosis and as an aid to countries where control schemes for the disease are in operation. Three enzyme-linked immunosorbent assays (ELISAs) were developed and validated, using as antigen either a purified 8 kDa hydatid cyst fluid protein (8kDaELISA), a recombinant EG95 oncosphere protein (OncELISA) or a crude protoscolex preparation (ProtELISA). Sera used for the assay validations were obtained from 249 sheep infected either naturally or experimentally with E. granulosus and from 1012 non-infected sheep. The highest diagnostic sensitivity was obtained using the ProtELISA at 62.7 and 51.4%, depending on the cut-off. Assay sensitivities were lower for the 8kDaELISA and the OncELISA. Diagnostic specificities were high, ranging from 95.8 to 99.5%, depending on the ELISA type and cut-off level chosen. A few sera from 39 sheep infected with T. hydatigena and from 19 sheep infected with T. ovis were recorded as positive. Western immunoblot analysis revealed that the dominant antigenic components in the crude protoscolex antigen preparation were macromolecules of about 70-150 kDa, most likely representing polysaccharides. This study demonstrated that the ProtELISA was the most effective immunological method of those assessed for detection of infection with E. granulosus in sheep. Because of its limited diagnostic sensitivity of about 50-60%, it should be useful for the detection of the presence of infected sheep on a flock basis and cannot be used for reliable identification of in idual animals infected with E. granulosus.
Publisher: Elsevier BV
Date: 08-2004
Publisher: Elsevier BV
Date: 11-2006
DOI: 10.1016/J.VETPAR.2006.06.027
Abstract: Recent work on Neospora caninum, a protozoan parasite that causes abortions in dairy cattle has focused on a number of different control options. Modelling has suggested the most effective options for control but the present paper argues that the most effective option might not necessarily be optimal from an economic point of view. Decision trees, using published quantitative data, were constructed to choose between four different control strategies. The costs of these interventions, such as 'test and cull', therapeutic treatment with a pharmaceutical, vaccination or "doing nothing" were compared, and modelled, in the first instance, on the New Zealand and Australian dairy situation. It is argued however, that the relative costs in other countries might be similar and that only the availability of a registered vaccine will change the decision tree outcomes, as does the within-herd prevalence of N. caninum infection. To "do nothing" emerged as the optimal economic choice for N. caninum infections/abortions up to a within-herd prevalence of 18%, when viewed over a 1-year horizon, or 21% when costs were calculated over a 5 years horizon. For a higher (>or=21%) within-herd prevalence of N. caninum infection vaccination provided the best (i.e. most economic) strategy. Despite being the most efficacious solutions, 'test and cull' or therapeutic treatment never provided a viable economic alternative to vaccination or "doing nothing". Decision tree analysis thus provided clear outcomes in terms of economically optimal strategies. The same approach is likely to be applicable to other countries and the beef industry, with only minor changes expected in the relationships of decisions versus within-herd prevalence of N. caninum infection.
Publisher: Springer Science and Business Media LLC
Date: 30-12-2014
Publisher: Springer Science and Business Media LLC
Date: 07-01-2015
DOI: 10.1007/S11250-014-0748-5
Abstract: The objective of the current survey was to provide an update on pig farming practices in the Jayawijaya region, Papua Province, Indonesia. A structured semi-close-ended questionnaire was used to interview 367 farmers across the Jayawijaya region. Results showed that farms, on average, comprised of 8.8 pigs (CI 8.5-9.1). The average litter size was 6.0 (CI 5.7-6.3) piglets, the farrowing frequency was once a year, and the annual mortality rate was 50.2% (CI 48.4-51.9). On average, 43.4% farms (CI 36.4-50.7) allowed pigs to roam freely during daylight hours. Farmers used pigs for their own consumption (62.4%, CI 57.4-67.4), as a gift (56.6%, CI 51.5-61.7), or for sale (50.7%, CI 45.6-55.8). Veterinary services were used intensively by just 11.7% of farmers (CI 8.2-16.5). Furthermore, 34.2% (CI 29.3-39) of farmers would sell sick pigs, and 63.1% (CI 58.2-68.1) would slaughter and consume them. It was also recorded that 68.6% of farmers (CI 63.7-73.4) would eat sick pigs that had died naturally. These findings suggest that traditional pig farms in Jayawijaya are of low productivity. Moreover, the free roaming of pigs and the sale and consumption of sick pigs have the potential to allow pathogens to circulate between pig and human populations.
Publisher: Elsevier BV
Date: 07-2014
DOI: 10.1016/J.VETPAR.2014.04.011
Abstract: The aim of this study was to investigate how Neospora caninum serostatus may be affected by variables such as host species (water buffaloes or cattle) and age in animals cohabiting in the same ranch. A convenience cross-sectional study was performed on four ranches in the Northeast of Argentina, where water buffalo are cohabitating with beef cattle. Blood s les were collected from 1350 female water buffaloes (Bubalus bubalis) and 880 female beef cattle (Bos taurus and Bos indicus crossbreeds) from four ranches. Calving and weaning percentages at herd level for each ranch were also recorded. N. caninum antibody levels were measured by an indirect fluorescent antibody test (IFAT) (reciprocal antibody titers ≥ 100). Serological results were classified into 2 categories (0: negative 1: positive). A logistic regression model was used to describe the relationship between N. caninum serostatus and specie (water buffalo or cattle), age or ranch and their interactions. Likelihood ratio tests were used to assess the significance of the model and their terms. Odds ratios were estimated and 95% profile likelihood (LR) and Wald confidence intervals (CI) obtained. Overall, specific antibody titers were found in 43.3% (584/1350) of water buffaloes and 28.6% (252/880) of cattle. Seropositive water buffaloes and cattle were observed on all ranches. Age was statistically significant (p=0.01) with an overall estimate of logit (log odds) of age of 0.03 for both species. This indicates that for every one year increase in age, the expected change in log odds of being seropositive increased by 0.03. On three of four ranches a water buffalo was 4.48, 1.54 and 2.25 times more likely to be seropositive than cattle for animals of the same age. The N. caninum serostatus was affected by age in the first place, but also by species on at least three of the four ranches. Calving and weaning percentages were higher in water buffaloes than in beef cattle (p<0.05). Even though the low pathogenicity that N. caninum seems to have in water buffaloes, this study reinforces the importance of this specie as maintenance of the disease.
Publisher: Informa UK Limited
Date: 10-1996
DOI: 10.1080/00480169.1996.35966
Abstract: Seventy-nine suspected false-positive sera, obtained over 1 year from routine submissions for Brucella ovis serological testing, were used in this study. These sera, which exhibited titres in the complement fixation test, but which because of their epidemiological history and their reactions in the enzyme-linked immunosorbent assay and gel diffusion test were suspected to be false positives, were further analysed by immunoblotting. In blots, using B. ovis antigens, rough lipopolysaccharide was identified as the major, immuno-reactive bacterial component. Antibodies against this macromolecule were present in 46.8% of the suspected false-positive sera. In order to find out if rough lipopolysaccharides from other bacterial species could be the possible cause for the suspected false positivity, 23 sera with highest complement fixation titres were reacted in blots with cell extracts from Escherichia coli, Yersinia enterocolitica, Yersinia pseudotuberculosis, Bortedella bronchiseptica, Actinobacillus seminis, C ylobacter fetus fetus, C ylobacter jejuni, Mycobacterium paratuberculosis, Mycobacterium phlei, Corynebacterium pseudotuberculosis and pure lipopolysaccharides from Escherichia coli and Salmonella typhimurium. Despite high frequencies of antibody reaction with proteins in most of these bacterial cell extracts, which reflect the presence of infections with these bacteria, immuno-staining in the rough lipopolysaccharide region was not observed.
Publisher: Informa UK Limited
Date: 08-1996
DOI: 10.1080/00480169.1996.35960
Abstract: An indirect immunofluorescent antibody test (IFAT) and an enzyme-linked immunosorbent assay (ELISA) for specific anti-Neospora antibodies in bovine sera and foetal fluids were compared with histological examination results on aborted foetal material. The agreement between serological and histological examination results was poor, while the two serological tests showed a high degree of agreement. Serological testing of diagnostic serum s les and foetal fluids suggests that the prevalence of anti-Neospora antibodies in cattle which recently aborted is around 40%, in line with previous estimates of the number of abortions in dairy cattle caused by Neospora sp. A sero-epidemiological approach to the diagnosis of Neospora abortions in cattle may be suggested from these data.
Publisher: Wiley
Date: 05-02-2007
DOI: 10.1111/J.1748-5827.2006.00236.X
Abstract: The dog is a definitive host of the protozoan parasite Neospora caninum, and in many parts of the world, infection is relatively common as determined by serology. Reported seroprevalences usually range from 0 to 20 per cent, however, reports of clinically affected dogs are infrequent. Affected dogs are generally less than six months old and predominantly have signs of an ascending hindleg paralysis, with the associated lesions of polyradiculoneuritis and granulomatous polymyositis. Although any organ may be affected, infections are more common in the central nervous system, muscles, lungs and skin. Ante-mortem diagnosis is difficult but serology and cytology can aid diagnosis. The diagnosis can be confirmed by histology, immunohistochemistry, the use of molecular techniques on biopsy material, or on post-mortem examination. Neospora caninum oocysts are rarely found in faeces and must be differentiated from oocysts of related coccidians such as Hammondia heydorni and Toxoplasma gondii. Hammondia heydorni can cause diarrrhoea in immunosuppressed dogs. Neosporosis should be suspected in young pups with an ascending paralysis of the hindlegs. Treatment with clindamycin and potentiated sulphonamides may be useful in cases where muscular atrophy and fibrosis are absent. Feeding of raw meat is a potential risk factor for infection of dogs and should be discouraged.
Publisher: Wiley
Date: 04-2000
DOI: 10.1111/J.1751-0813.2000.TB11751.X
Abstract: To review the current state of knowledge of Neospora caninum infections with particular reference to Australia and New Zealand. Several databases were searched electronically including Medline, Current Contents, Vet CD using several key words (Neospora caninum, neosporosis, abortion, cattle, dogs) and authors names. References in original articles were also traced and use made of the author's own original research in the field. N caninum is recognised worldwide and is also widespread, in particular in dairy cattle, in Australia and New Zealand. It has been reported in both countries retrospectively (in dogs) from the early 1970s. Abortion storms in dairy herds appear to be the most common feature. Recent reports indicate that the dog is the definitive host, in which the sexual cycle is completed. Further studies are however required to establish important aspects of the epidemiology, such as mode of transmission. In the absence of an effective vaccine, the most effective control strategy is selective culling of infected animals and the prevention of access of dogs to expelled placentas and foetuses and, possibly, to raw beef.
Publisher: SAGE Publications
Date: 12-03-2014
Abstract: Testing for specific antibodies against Bovine viral diarrhea virus (BVDV) in pooled serum may present an opportunity to decrease the cost of screening for herds of high seroprevalence and increased likelihood of active infection. Experimental serum pools ( n = 280) were created by combining equal aliquots of serum from between 5 and 25 in iduals. A further 188 serum pools were generated from field serum s les. All pools and in idual sera were tested for BVDV-specific antibodies by enzyme-linked immunosorbent assay (ELISA), according to manufacturer’s instructions. Pools returned repeatable results, with coefficients of variation generally below 10%. The presence of serum from a persistently infected (PI) in idual in the pool had no significant effect on the ELISA s le-to-positive (S/P) ratio. The results revealed that a single strong antibody-positive in idual could maintain a positive result (at the manufacturer’s threshold) in pools of up to 128, while even a single weak-positive animal would generate a positive result in pools of up to 8. The S/P ratio of the pool was positively related to the within-pool prevalence of antibody-positive in iduals. However, as the strength of the in idual positive animals contributing to the pool had a large effect on the pool S/P ratio, the S/P ratio could not be used to accurately predict the within-pool prevalence of field serum pools. An alternative method of S/P ratio interpretation was pursued, and a two-graph receiver operating characteristic analysis allowed segregation of pools into low, medium, and high risk with good results when applied to field serum pools.
Publisher: The Scientific and Technological Research Council of Turkey (TUBITAK-ULAKBIM) - DIGITAL COMMONS JOURNALS
Date: 2014
DOI: 10.3906/VET-1310-36
Publisher: Elsevier BV
Date: 10-2015
DOI: 10.1016/J.PARINT.2015.05.009
Abstract: The seroprevalence of Neospora caninum infection in water buffalo (Bubalus bubalis) and domestic cattle in the Northern Territory (NT) of Australia has never been determined. A total of 480 serum s les from water buffalo and 192 serum s les from cattle, collected by the NT Government from 1993 through to 2001, at 18 different survey sites throughout the Northern Territory were tested by commercial ELISA for anti-N. caninum antibodies. The water buffalo s les demonstrated a seroprevalence of 88.3% (95% CI ± 2.9%), while 31.8% (±6.1%) of the cattle sera tested positive for N. caninum antibodies. In idual buffalo from the same herd, s led over years, showed considerable fluctuations in S/P ratios. Overall, seropositivity was consistent across buffalo herds, and showed a slight decline over the years. The study presents evidence for the first time that N. caninum infection in water buffalo in the Northern Territory is a highly endemic and that infection rates are higher than those for cattle. This is important for an understanding of any potential sylvatic life cycle of N. caninum in Northern Australia. This survey also tests cattle from that territory for the first time for evidence of N. caninum infection and makes an important contribution to the understanding of disease management issues for the beef industry in the region.
Publisher: Wiley
Date: 28-03-2016
DOI: 10.1111/AVJ.12421
Abstract: Blood s les were collected from 69 'healthy' female alpacas aged ≥12 months from 11 properties in South Australia. The 10-90 percentile ranges of the 16/19 analytes measured in this s le population were within the published ranges of four healthy alpaca populations from other geographic locations. Marginal exceptions were glutamate dehydrogenase and bicarbonate. Potassium was notably elevated, probably because of haemolysis of some s les. The s le size was insufficient to provide the appropriate statistical power to define diagnostic references ranges according to international standards. The health status of the s le population of alpacas was presumptive based on a physical examination.
Publisher: MDPI AG
Date: 09-03-2015
Publisher: Wiley
Date: 30-10-2013
DOI: 10.1111/J.1751-0813.2012.01010.X
Abstract: To compare the performance of an enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies specific to bovine viral diarrhoea virus (BVDV) with a virus neutralisation test (VNT) and agarose gel immunodiffusion (AGID) test. A total of 125 cattle serum s les were tested by a commercially available ELISA for antibodies specific to BVDV and by a VNT as the reference standard. A comparison between AGID and ELISA for detection of BVDV antibodies was also carried out, using 1182 serum s les from unvaccinated South Australian cattle. Two-graph receiver operating characteristics (TG-ROC) analysis was used to confirm that the manufacturer's recommended cut-off value for the ELISA was appropriate. Two-by-two tables were constructed to analyse the concordance of serological results among the three assays. McNemar tests were used to assess the agreement among serological tests. Using the manufacturer's cut-off threshold, supported by TG-ROC analysis, the ELISA's sensitivity and specificity were calculated to be 96.7% and 97.1%, respectively, compared with the VNT. Compared with AGID, ELISA with specific BVDV antibodies may be more sensitive and detect 5.8% more s les than AGID. McNemar test also showed a significant difference (P < 0.001) between AGID and ELISA.
Publisher: Informa UK Limited
Date: 06-1996
Publisher: Elsevier BV
Date: 02-2015
Publisher: Elsevier BV
Date: 2004
DOI: 10.1016/J.VETIMM.2003.08.002
Abstract: Interleukin 4 (IL-4) is expected to play a dominant role in the development of T helper (Th) 2 cells. Th2 immune responses with expression of relatively large amounts of interleukin 4 (IL-4) but little interferon gamma (IFN-gamma) are characteristic for chronic helminth infections. But no information is available about IL4 expression during early Fasciola hepatica (F. hepatica) infections in cattle. Therefore, we investigated F. hepatica specific IL-4 and IFN-gamma mRNA expression in peripheral blood mononuclear cells (PBMCs) from calves experimentally infected with F. hepatica. Cells were collected prior to infection and on post-inoculation days (PIDs) 10, 28 and 70. Interestingly, PBMCs responded to stimulation with F. hepatica secretory-excretory products (FhSEP) already on PID 10 and expressed high amounts of IL-4 but not of IFN-gamma mRNA suggesting that F. hepatica induced a Th2 biased early immune response which was not restricted to the site of infection. Later in infection IL-4 mRNA expression decreased whereas IFN-gamma mRNA expression increased slightly. Isolated lymph node cells (LNCs) stimulated with FhSEP and, even more importantly, non-stimulated LN tissue s les indicated highly polarized Th2 type immune responses in the draining (hepatic) lymph node, but not in the retropharyngeal lymph node. During preliminary experiments, two splice variants of bovine IL-4 mRNA, boIL-4delta2 and boIL-4delta3, were detected. Since a human IL-4delta2 was assumed to act as competitive inhibitor of IL-4, it was important to know whether expression of these splice variants of bovine IL-4 have a regulatory function during an immune response to infection with F. hepatica. Indeed, IL-4 splice variants could be detected in a number of s les, but quantitative analysis did not yield any clue to their function. Therefore, the significance of bovine IL-4 splice variants remains to be determined.
Publisher: Elsevier BV
Date: 09-2016
Publisher: Informa UK Limited
Date: 04-2008
DOI: 10.1080/00480169.2008.36809
Abstract: To provide an economic analysis of the costs of control or eradication of bovine viral diarrhoea (BVD) against the estimated costs of the disease. A decision-tree approach was adapted to an analysis of the costs of bovine viral diarrhoea virus (BVDV) infection and that of three main control options (vaccination, test-and-cull, and increased biosecurity) and their combinations, to the dairy industry in New Zealand. The model was based on an average herd of 322 milking cows. Endemic, epidemic and sporadic effects of BVDV infection were modelled in the herd, to derive an estimate of costs. The cost of BVDV infection to an infected average-sized dairy herd in New Zealand was estimated to be NZ $11,334 (or NZ $35.19 per cow) per annum, and NZ $48,311 over 10 years. Based on these calculations, the estimate of the annual cost of BVDV infection to the dairy industry in New Zealand was in excess of NZ $23 million per annum. While all of the control options required financial input, the rate of return compared with the cost of BVD, when viewed over a 10-year term, was as high as 123%. All control options offered considerable savings compared with the cost of BVD infection, and control is economically favourable. Uncertainty over the likely efficacy of the control options under field conditions in New Zealand would not allow a firm choice of one option over another at this stage, and more work on determining the efficacy of those control options in New Zealand is needed.
Publisher: SAGE Publications
Date: 08-02-2017
Abstract: Effective control and the eventual eradication of Bovine viral diarrhea virus (BVDV) from cattle populations depend on the accurate identification of infected animals. Although typically a disease agent of cattle, BVDV is known to infect a wide variety of nonbovine species, including sheep. However, validation of serologic tests in these nonbovine species, particularly sheep, is lacking. We analyzed 99 sheep sera (57 s les from Pestivirus-naive sheep, and 42 s les from BVDV-inoculated sheep) in order to investigate 3 serologic tests: the agarose gel immunodiffusion (AGID) and 2 commercial enzyme-linked immunosorbent assays (ELISAs) for detection of BVDV antibodies. At the manufacturer’s cutoff thresholds, the AGID performed with 95.2% diagnostic sensitivity ELISA-A performed with sensitivity of 90.5% and ELISA-B with 69.1%. All 3 tests performed with 100% diagnostic specificity. Two-graph receiver operating characteristic analysis showed that performance characteristics were optimized, such that both diagnostic sensitivity and diagnostic specificity were % for both ELISAs, if the thresholds were altered to 34.9% inhibition for ELISA-A and 63.5 signal-to-noise ratio for ELISA-B.
Publisher: Elsevier BV
Date: 2015
Publisher: SAGE Publications
Date: 23-12-2015
Abstract: Colostrum may have the ability to improve the diagnostic accuracy of some tests when compared to serum for important livestock diseases because of the high concentrations of immunoglobulins present within this s le type. The ELISA for Johne’s disease is one such test, as it suffers from low sensitivity when testing serum s les collected during the subclinical stage of infection. Blood and colostrum s les were collected from 34 Jersey dairy cows and tested for antibodies against Mycobacterium avium subspecies paratuberculosis (MAP) by ELISA. Fecal s les were also collected and tested by a high-throughput Johne’s polymerase chain reaction (HT-J PCR) assay and fecal culture (FC), with the latter being used as the reference test. A receiver operating characteristic (ROC) analysis was performed, and the area under the curve (AUC) was calculated. The HT-J PCR and FC results were also compared. Of the 34 cows in this study, 4 had FC results consistent with MAP infection. The HT-J PCR did not identify any FC-positive cows. Using a 1:20 dilution and s le-to-positive (S/P) ratio cutoff threshold of 0.15, the relative sensitivity values of both serum (AUC 0. 56) and colostrum (AUC 0.63) were 0%. With lower s le dilutions, the relative sensitivity values of serum were 0% (1:2, AUC 0.62 1:5, AUC 0.55) however, the relative sensitivity value of colostrum was 75% (95% confidence interval [CI]: 19–99%) at a dilution of 1:5, S/P ratio cutoff threshold of 0.15, and AUC of 0.73 (95% CI: 0.55–0.87). The testing of colostrum s les for MAP-specific antibodies by ELISA may provide improved identification of animals in the early stages of infection with MAP when compared with serum s les.
Publisher: Elsevier BV
Date: 09-2009
DOI: 10.1016/J.IJPARA.2009.05.007
Abstract: Neospora caninum is a protozoan parasite that causes abortion in cattle around the world. Although the clinical signs of disease in both dogs and cattle have now been recognised for over 20years, treatment and control options are still limited, despite the availability of a commercial vaccine in some countries of the world. The case for an efficacious vaccine has not been convincingly waged by farmers, veterinarians and other members of the agricultural and rural communities. In recent times, however, economic modelling has been used to estimate the industry losses due to Neospora-associated abortion, providing, in turn, the business case for forms of control for this parasite, including the development of vaccines. In this review, we document progress in all areas of the vaccine development pipeline, including live, killed and recombinant forms and the animal models available for vaccine evaluation. In addition, we summarise the main outcomes on the economics of Neospora control and suggest that the current boom in the global dairy industry increases the specific need for a vaccine against N. caninum-associated abortion.
Publisher: Wiley
Date: 24-01-2021
DOI: 10.1002/VETR.6
Abstract: Background : Acute bovine viral diarrhoea virus (BVDV) infections in sheep are largely sub‐clinical although infections of pregnant ewes have shown to result in significant fetal losses and persistently infected lambs. However, the extent and severity of abnormalities in lambs infected with BVDV in utero is still largely unknown. Methods : Twenty‐two ewes were experimentally infected with BVDV‐1c between 59 and 69 days of gestation. Fifteen lambs were submitted for pathological examination and the abnormalities observed in lambs and fetuses characterised. Results : Six lambs were identified as BVDV negative, and nine were identified as BVDV positive. Anasarca and cholestatic hepatopathy was observed in four BVDV positive lambs and associated with ewes with early seroconversion. One BVDV positive lamb was born with muscular tremors and a hairy coat associated with primary follicular dysplasia, a developmental abnormality normally associated with border disease infected lambs. Conclusion : If similar lambing outcomes are identified in a commercial setting then BVDV should be considered, particularly in areas where sheep regularly come in to contact with cattle. In addition, as far as the authors are aware, this is the first reported case of a ‘hairy shaker’ lamb born as a result of an infection with BVDV‐1c in Australia.
Publisher: Wiley
Date: 12-2014
DOI: 10.1136/VR.G7579
Publisher: Springer Science and Business Media LLC
Date: 24-09-2021
Publisher: Elsevier BV
Date: 04-2010
DOI: 10.1016/J.VETMIC.2009.09.047
Abstract: An increase in veterinary and farmer interest in bovine viral diarrhoea (BVD) in New Zealand over recent years led to requests for cost-effective identification of BVD virus (BVDV) infected herds and in iduals. This study was undertaken to determine if the use of real-time reverse transcriptase polymerase chain reaction (RT-PCR) technology and dairy cow production data could identify persistently infected (PI) animals in milking herds. Milk s les were collected from the vats of dairy herds and tested for the presence of BVDV by RT-PCR till four herds were found containing PI animals. In idual serum s les were then collected from every cow in the herd and tested by both RT-PCR and antigen capture enzyme-linked immunosorbent assays (ACE) to identify the PI animals. In idual animal testing found 1/223, 1/130, 2/800 and 1/275 PI's respectively in the four herds. Based on these results a maximum pool size of 400 cows contributing to the bulk tank milk was selected. After removal of the PI from the herds, further bulk milk s les were shown to be BVDV negative by RT-PCR. All the PI animals identified by this method were found in the lowest producing 10-20% of herd. This approach of targeted testing of dairy herds using PCR technology, in conjunction with animal production information, markedly reduced the cost of diagnostic testing for BVDV in dairy herds in New Zealand. Questionnaire follow-up on 81 BVDV-positive herds (15% of those tested) indicated the stratification approach identified milking PIs successfully over 90% of the time and reduced the number of in idual tests to 12% of the milking herd.
Publisher: Elsevier BV
Date: 08-2006
DOI: 10.1016/J.VETPAR.2006.03.016
Abstract: To determine the performance characteristics of two enzyme-linked immunosorbent assays (ELISAs) manufactured by Institut Pourquier (IP) for the detection of antibodies against Neospora caninum in bovine sera. Sera from 526 cattle were assayed in two ELISAs (IP) for the detection of anti-N. caninum antibodies. Results from a further ELISA (IDEXX) were used to provide the "gold standard"N. caninum infection status of the cattle and the ELISA results assessed by two-graph receiver operating characteristic (TG-ROC) analysis. TG-ROC analysis suggested changes to one of the IP ELISA protocols, arriving at a cut-off threshold that was different to the one recommended by the manufacturer. With that change, both of the ELISAs performed with high sensitivity and specificity (in excess of 98%) for bovine sera. The analysis of the two IP ELISAs when used on in idual bovine sera demonstrated high sensitivity and specificity. TG-ROC analyses optimised the cut-off point suggested by the manufacturer for one of these commercial diagnostic assays and found agreement with the manufacturer's cut-off regarding the other assay. This will help with the accurate identification of infected animals and thereby contributing to the control of neosporosis.
Publisher: Elsevier BV
Date: 09-1997
DOI: 10.1016/S0378-1135(97)00136-3
Abstract: A direct polymerase chain reaction (PCR) test was applied to DNA extracted from blood, liver, ileocecal lymph node and ileum from twelve ewes in poor condition with histologically confirmed paratuberculosis and ten clinically normal sheep which had no evidence of paratuberculosis. The assay was compared with four serological tests: complement fixation test (CFT), gel diffusion test (AGID) and two enzyme-linked immunosorbent assays (ELISA). The PCR detection rate of Mycobacterium avium subsp. paratuberculosis, when results of single tests were interpreted in duplicate, was 72% for ileocecal lymph node, 90% for liver, and 100% for ileum in sheep with confirmed paratuberculosis. A single PCR test detected the target DNA in 66% of 0.5 ml blood s les. Sensitivities of serological tests compared with histological diagnosis were: 33% for CFT, 66% for AGID, 75% for the Central Animal Health Laboratory (CAHL) ELISA, and 83% for the 'modified' Commonwealth Serum Laboratories (CSL) ELISA. The PCR assay gave no positive reaction in s les collected from 10 sheep considered to be free of paratuberculosis. Similarly, all four serological tests were also 100% specific. The results raise some hope for the development of a PCR-based test using liver biopsy specimens, or possibly blood, in the diagnosis of paratuberculosis in sheep.
Publisher: Informa UK Limited
Date: 04-1999
DOI: 10.1080/00480169.1999.36114
Abstract: To describe the performance characteristics (sensitivity and specificity) of an enzyme-linked immunosorbent assay (ELISA) for the diagnosis of Brucella ovis infection in rams. Sera from a negative (n = 2535) and a positive (n = 589) reference population were tested in an ELISA for anti-B. ovis antibodies and cut-off values calculated from the raw, log10-transformed and fitted data. Statistical methods were used to fit curves to the frequency distribution of the data and receiver-operated characteristics analysis used to optimise the cut-off values. Analysis of the frequency distribution of the positive ELISA values suggested a normal distribution of the data, whereas, in the case of the negative population, a Pearson type IV curve appeared to best fit the data. The cut-off values calculated as the mean plus 1.96 standard deviations (s.d.) from the raw, log-transformed and fitted ELISA data did not differ markedly. The differences were much greater at the mean plus 3.09 s.d. cut-off, with the cut-off value calculated from the log-transformed data giving a much better estimate of specificity. Optimisation (minimisation of classification error) of the cut-off calculated from the fitted curves suggested varying cut-off values, depending on the prevalence of B. ovis infection. Calculation of cut-off values from curves that were fitted from the observed data give more accurate estimations of the performance characteristics of an assay than traditional calculations from observed values. They also allow the calculation of optimal cut-off values taking into account the prevalence of B. ovis infection and give additional information about the performance of the assay at cut-off values varied according to the epidemiological situation.
Publisher: Public Library of Science (PLoS)
Date: 09-04-2020
Publisher: Wiley
Date: 12-10-2015
DOI: 10.1111/AVJ.12374
Abstract: Bovine viral diarrhoea virus (BVDV) and Neospora caninum may cause clinical disease in alpacas. Both diseases are present in the Australian cattle population. The objective of this study was to perform a serological prevalence survey for BVDV and N. caninum exposure in a regional alpaca population of South Australia. Serum s les were taken from 182 alpacas on 10 farms, which had a combined population of 1308 alpacas. Serological analysis for BVD antibodies was performed using a competitive BVDV antibody ELISA kit. Serological analysis for N. caninum was performed using an anti-Neospora ELISA with a protein G conjugate. Of the 182 alpacas s led, 5 animals located on three properties were positive for BVDV antibodies, constituting a prevalence of 2.7% (95% confidence interval 1-6%). All s les tested negative for N. caninum antibodies. There is a low BVDV seroprevalence and N. caninum is currently either absent or present at a very low prevalence in this population of alpacas in South Australia. There is serological evidence for the presence of both organisms in South Australian beef and dairy cattle herds. Appropriate biosecurity protocols to minimise the risk of introduction and exposure should be a high priority to maintain this favourable status.
Publisher: ResearchersLinks Ltd
Date: 04-2018
Publisher: Elsevier BV
Date: 2018
DOI: 10.1016/J.ACTATROPICA.2017.10.007
Abstract: N. caninum, bovine viral diarrhoea virus, Brucella abortus and Leptospira interrogans serovar Hardjo are globally significant reproductive pathogens that cause abortion and reproductive loss in large ruminants. Prevalence information is lacking in Lao People's Democratic Republic (Laos) despite the poor reproductive performance of cattle and buffalo. Serological examination of frozen cattle (n=90) and buffalo (n=61) sera by commercially available enzyme-linked immunosorbent assays provided the first reported screening of some of these pathogens in Laos. Seroprevalence differed amongst these large ruminant species, with N. caninum, BVDV and L. interrogans serovar Hardjo antibodies found in 68.9% (95% CI±11.6), 4.9% (95% CI±5.4) and 3.3% (95% CI±4.5) of buffalo sera, respectively, and in 7.8% (95% CI±5.5), 10.0% (95% CI±6.2) and 22.2% (95% CI±8.6) of cattle sera, respectively. Buffalo sera had a significantly higher seroprevalence of N. caninum compared to cattle (p<0.001) and cattle sera had a significantly higher seroprevalence of L. interrogans serovar Hardjo compared to buffalo (p=0.003). Variability was also observed across provinces for N. caninum in buffalo (p=0.007) and for L. interrogans serovar Hardjo in cattle (p=0.071), suggesting provincial risk factors conducive to pathogen transmission. BVDV and N. caninum seropositivity were negatively associated in buffalo (p=0.018) and cattle (p=0.003). In buffalo, L. interrogans serovar Hardjo and BVDV seropositivity were associated (p=0.035, p=0.039). The identification of antibodies against three major abortifacient pathogens in Laos prompts further research to determine if infection is associated with low reproductive efficiency and the risk factors for infection. This is needed for the development of evidence based prevention strategies for improved large ruminant reproductive management among smallholders in Laos.
Publisher: Elsevier BV
Date: 02-2010
DOI: 10.1016/J.MCP.2009.08.002
Abstract: Genetic ersity of Neospora caninum was investigated through a study of repetitive sequences found in the genome of this species. Twenty different loci were studied, and three were identified that varied in repeat content amongst isolates. No relationship was found between the copy number of repetitive sequences present and host type or geographical location from which the isolates were derived. A multiplex PCR assay was developed for multilocus-strain typing using three microsatellites and three minisatellites, based on the polymorphisms found in the repetitive sequences. This study therefore extends knowledge on the repetitive sequences found in the N. caninum genome and the ersity found within the species. It also provides a second generation multiplex assay that can be used to study the biology of N. caninum. In addition, this study included Neospora hughesi (along with other closely related apicomplexans) as controls. The present study shows N. hughesi to be quite distinct from N. caninum in these repetitive sequences, thereby potentially providing a new approach for the differentiation of these two taxa.
Publisher: SAGE Publications
Date: 26-03-2016
Abstract: Antigen enzyme-linked immunosorbent assay (ELISA) is used for the detection of Bovine viral diarrhea virus persistently infected (BVDV PI) cattle however, colostrum-derived antibodies may interfere with antigen detection in serum from young PI calves. Our study aimed to assess serum pretreatment methods for reducing such interference. Dilution of PI serum with serum containing specific antibody showed that antibody levels equivalent to those observed in colostrum-fed calves were able to eliminate all antigen signals in a serum s le. Serum was treated with ethylenediamine tetra-acetic acid at pH 4.5, 5.5, 6.5, and 7.5, then boiled, centrifuged, and the supernatant-recovered. BVDV antibody was undetectable by ELISA in supernatants from treated s les, and the antigen ELISA signal was improved. Maximum antigen signal recovery of % was achieved at pH 5 ± 0.5. When this optimal treatment method was applied to field s les from 3 PI calves (which were negative in the antigen-capture ELISA without treatment), the antigen signal improved and gave a positive result in each case. Pretreatment may provide an improvement in the detection of young PI calves.
Publisher: Elsevier BV
Date: 10-2008
Publisher: Elsevier BV
Date: 04-2005
DOI: 10.1016/J.VETPAR.2004.12.013
Abstract: To determine the performance characteristics of an enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies against liver fluke (Fasciola hepatica) in bovine milk. Serum and milk from liver fluke infected and non-infected cattle was assayed in a commercially available enzyme-linked immunosorbent assay. Serum test results were used to determine the "gold standard" infection status of cattle and milk ELISA results assessed by ROC analysis. ROC analysis suggested changes to the ELISA protocol, arriving at milk dilutions assayed considerably higher than those suggested by the manufacturer. With those changes, the ELISA performed with high sensitivity and specificity, 95 and 98.2%, respectively, for in idual bovine milks (relative to sera). For bovine tank milks, sensitivity was lower, with bulk milks only testing positive if 60% or more of cattle milking in the herd were infected. The analysis of the ELISA's performance when used on in idual bovine milks demonstrated high sensitivity and specificity. ROC analyses optimised the assay conditions and cut-off point suggested by the manufacturer for this commercial diagnostic assay. This would help with the identification and control of fasciolosis, enabling simpler s le collection.
Publisher: Scientific Research Publishing, Inc.
Date: 2015
Publisher: Elsevier BV
Date: 03-2005
DOI: 10.1016/J.VETPAR.2004.12.012
Abstract: To determine the contribution of Neospora caninum to abortions on a dairy farm in NSW (Australia), determine the mode of transmission and develop and trial a control option for infection. Two whole herd bleeds were conducted 12 months apart and the association between serological status and abortion events were calculated for a number of bovine abortifacients. Family trees were constructed for N. caninum seropositive cattle in the herd. Some N. caninum seropositive cows were culled from the herd and no female offspring was retained from seropositive cows. At the first whole-herd bleed in December 2002 a seroprevalence of 10.2% for N. caninum infection was detected. Cows with N. caninum infection were 13 times more likely to abort than uninfected ones. Seventy-five percent of seropositive animals in the herd were related, suggesting a high degree of congenital infection/transmission. Only 15% of infections were likely to be postnatally acquired. Selective culling of seropositive cows and not breeding from them reduced the number of seropositive animals. Only one newly sero-converted cow was detected at the second whole-herd bleed 12 months later. Seroepidemiological approaches were able to establish a high degree of association between N. caninum infection and low-level abortion in the dairy herd. Vertical transmission of infection was the predominant mode of infection and hence control efforts aimed at selectively culling seropositive animals from the herd were highly successful in reducing the level of infection.
Publisher: Wiley
Date: 24-04-2015
Publisher: MDPI AG
Date: 07-02-2022
DOI: 10.3390/PATHOGENS11020215
Abstract: This review aims to update the knowledge of the epidemiology of Bovine viral diarrhoea virus (BVDV) in Indonesia and Southeast Asia and provide a perspective on the control options for BVDV in the Indonesian cattle population in the future. Studies on BVDV in Indonesia, since its first report in that country, and the updated beef and dairy cattle industries are reviewed. In ten of 34 provinces, BVDV is endemic. The subgenotypes of BVDV-1a and BVDV-1c are predominant in Indonesian cattle. However, BVDV is currently not a priority disease to control in Indonesia. Cattle imports from Australia appear to be potentially the most significant source of transmission of BVDV into native cattle, but the control of BVDV conducted in the local quarantine facilities is currently not achieving the aim of controlling BVDV thus, complementary measures are needed. With the small-scale nature of the vast majority of cattle breeding in the country, the control of BVDV in provinces in which cattle breeding is economically essential may need to be organised by regional and provincial governments. Gaps in our knowledge of BVDV are identified in this review, and strategies for the control of BVDV in Indonesia are discussed.
Publisher: Elsevier BV
Date: 06-2005
DOI: 10.1016/J.IJPARA.2005.03.006
Abstract: Infection with the protozoan parasite Neospora caninum is an important cause of abortion in cattle. A major source of infection is transplacental transfer of the parasite from mother to offspring during pregnancy. This study describes investigations on the immunisation of outbred Qs mice before pregnancy with live or a crude lysate of N. caninum (NC-Nowra isolate) to prevent transplacental transfer of a challenge infection administered during pregnancy. Parasites present in the brains of pups from mice challenged with N. caninum (NC-Liverpool) were detected by PCR. Injection of live NC-Nowra tachyzoites before pregnancy dramatically reduced transplacental transfer from 75 to 0.8% in one experiment and from 76 to 8% in a second experiment. Injection of a crude lysate of NC-Nowra tachyzoites reduced transplacental transfer from 67 to 53% in one experiment and from 76 to 63% in a second experiment. Analysis of N. caninum-specific IgG1 and IgG2a antibody levels prior to pregnancy and challenge showed that NC-Nowra lysate induced a response skewed towards IgG1 whereas live parasites induced both IgG1 and IgG2a antibodies. After pregnancy and a challenge infection, a similar IgG1/IgG2a response was seen in all challenged groups. These results provide further positive support for the hypothesis that transplacental transmission of this parasite is preventable by vaccination.
Publisher: American Society of Parasitologists
Date: 02-2012
DOI: 10.1645/GE-2863.1
Publisher: MDPI AG
Date: 21-08-2023
DOI: 10.3390/PATHOGENS12081067
Abstract: Infectious diseases of cattle, including bovine viral diarrhea (BVD), pose a significant health threat to the global livestock industry. This study aimed to investigate the prevalence and risk factors associated with bovine viral diarrhea virus (BVDV) infections in cattle populations through a systematic review and meta-analysis. PubMed, Web of Science, and Scopus were systematically searched for relevant articles reporting the prevalence of and associated risk factors in studies published between 1 January 2000 and 3 February 2023. From a total of 5111 studies screened, 318 studies were included in the final analysis. BVDV prevalence in cattle populations was estimated using various detection methods. The analysis detected heterogeneity in prevalence, attributed to detection techniques and associated risk factors. Antibody detection methods exhibited a higher prevalence of 0.43, reflecting the cumulative effect of detecting both active and past infections. Antigen detection methods showed a prevalence of 0.05, which was lower than antibody methods. A prevalence of 0.08 was observed using nucleic acid detection methods. The health status of the examined cattle significantly influenced the prevalence of BVDV. Cattle with bovine respiratory disease complex (BRDC) exhibited higher antibody (prevalence of 0.67) and antigen (prevalence 0.23) levels compared to cattle with reproductive problems (prevalence 0.13) or diarrhea (prevalence 0.01). Nucleic acid detection methods demonstrated consistent rates across different health conditions. Age of cattle influenced prevalence, with higher rates in adults compared to calves. Risk factors related to breeding and reproduction, such as natural or extensive breeding and a history of abortion, were associated with increased prevalence. Coinfections with pathogens like bovine herpesvirus-1 or Neospora caninum were linked to higher BVDV prevalence. Management practices, such as commingling, introducing new cattle, and direct contact with neighboring farms, also influenced prevalence. Herd attributes, including larger herd size, and the presence of persistently infected cattle, were associated with higher prevalence. These findings indicated the importance of detection methods and risk factors in BVDV epidemiological studies.
Publisher: Wiley
Date: 26-10-2016
DOI: 10.1111/AVJ.12517
Abstract: Farmed and feral water buffaloes (Bubalus bubalis) populations often coexist with cattle in the Northern Territory of Australia, but their level of exposure to bovine viral diarrhoea virus (BVDV) is unknown. Water buffalo (n = 245) and cattle (n = 184) serum s les were collected by the NT Government as part of an ongoing disease surveillance scheme at varying intervals between 1993 and 2001. All s les were frozen and stored at -80°C until testing. Water buffalo s les from farming properties were identified as 'farmed' animals and the remaining s les as 'feral' populations. Serum s les were analysed using commercially available ELISAs to test for the presence of BVDV antibodies. Testing of historical water buffalo sera for BVDV antibodies revealed a low level of exposure, with 4.5% (95% CI ± 2.6%) being sero-positive cattle from the same geographical area and time period had higher levels of exposure at 74.5% (95% CI ± 6.3%). This survey showed that water buffalo are susceptible to infection with BVDV. No persistently infected water buffalo were identified in this study.
Publisher: Elsevier BV
Date: 07-1996
Publisher: American Society of Parasitologists
Date: 08-2013
DOI: 10.1645/12-42.1
Abstract: The present study evaluated the therapeutic efficacy of azithromycin, co-trimoxazole and kalvangi (Nigella sativa, also known as Black Cumin) against Cryptosporidium parvum infection in calves under field conditions. The experimental calves were treated with azithromycin (group A) at 1500 mg/calf/day, co-trimoxazole (group B) at 30 mg Kg-1 and kalvangi seeds powder (group C) at 750 mg Kg-1 BW orally for 7 days. Calves in the group D were naturally infected with C. parvum , untreated animals (positive control) while the calves in the group E were uninfected negative control animals. A significant decrease (p < 0.05) in oocyst counts for calves in groups A, B and C was observed compared to group D. When the oocyst counts amongst the treatment groups A, B and C were compared, a significant decrease (p < 0.05) was observed in group A. On day 21 post-treatment, the efficacy of azithromycin, co-trimoxazole and kalvangi in calves was 88.2% (95% C.I. ± 15.4), 45% (95% C.I. ± 21.8) and 27.8% (95% C.I. ± 20.7), respectively. This study confirmed previous reports of azithromycin efficacy against C. parvum infection, but found co-trimoxazole and kalvangi to be ineffective for this infection under these treatment regimens.
Publisher: Science Publications
Date: 04-2017
Publisher: Wiley
Date: 11-2000
DOI: 10.1111/J.1751-0813.2000.TB10452.X
Abstract: To compare the diagnostic performance of a complement fixation test, an agar gel immunodiffusion test, an enzyme-linked immunosorbent assay, and a whole-blood interferon-gamma assay for paratuberculosis in 14 sheep experimentally infected with Mycobacterium avium subsp paratuberculosis. Longitudinal study. The IFN-gamma assay detected more experimentally infected sheep, and earlier, than any of the serological tests. None of the antibody assays was able to detect all sheep with histologically confirmed paratuberculosis. The superior performance of the IFN-gamma assay in detecting infected sheep in this small experimental population warrants its further evaluation in a larger population of sheep naturally exposed to M a paratuberculosis.
Publisher: SAGE Publications
Date: 16-09-2014
Abstract: The diagnosis of neonatal and young calves persistently infected (PI) with Bovine viral diarrhea virus (BVDV) by antigen-capture enzyme-linked immunosorbent assay (ACE) may be complicated by interference from colostrum-derived specific antibodies. Ten calves, with 3 calves identified as PI and 7 as non-PI were used in the current study. All non-PI calves were shown to be seropositive for BVDV-specific antibodies by antibody enzyme-linked immunosorbent assay (Ab-ELISA) on serum. Serum s les, ear notch s les, and nasal and saliva swabs were collected from each calf from birth until 12 weeks of age and tested by ELISA for BVDV-specific antigen and antibodies. Following colostrum ingestion, Ab-ELISA s le-to-positive (S/P) ratios rose by a mean of 0.95 (95% confidence interval [CI] = 0.64–1.25) and 1.72 (95% CI = 1.55–1.89) in seropositive, non-PI calves and in PI calves, respectively. The mean S/P ratios then declined to approximately 1.1 in non-PI calves and 0.5 in PI calves at between 60 and 80 days of age. In PI calves, testing for antigen in serum and nasal and saliva swabs was subject to interference by colostrum-derived antibodies in calves up to 3 weeks of age. Nasal swabs were less affected than serum and saliva swabs. Ear notches maintained positive ACE corrected optical densities at all s le times, despite a drop in the signal following the ingestion of colostrum.
Publisher: Wiley
Date: 11-2002
DOI: 10.1111/J.1751-0813.2002.TB11303.X
Abstract: To assess the efficacy of two formulations of triclabendazole and ivermectin in combination against liver fluke (Fasciola hepatica), gastro-intestinal nematodes and sucking louse species in cattle and sheep. A study of 540 cattle and 428 sheep at 18 sites throughout Victoria and New South Wales was undertaken. At each site, one group of cattle or sheep was treated with a combined formulation (Fasimec Cattle or Fasimec Sheep), another received ivermectin and triclabendazole separately. In trials on lice infestation, an additional group remained untreated. S les for faecal egg counts were collected on days -7, 0 (treatment day), +7, +14 and +21 after treatment. Lice assessments were carried out on days -7, 0, +7, +14, +28, +42 and +56. Both treatments were highly efficacious (> 98% efficacy) against liver fluke in cattle and sheep, against three sucking lice species of cattle and against gastro-intestinal nematodes in sheep. There was also no significant difference between treatments in efficacy. Against gastro-intestinal nematodes, Fasimec Cattle was significantly (P < 0.01) more effective than the separately applied ivermectin and triclabendazole treatment. Mean efficacy for the Fasimec Cattle and Ivomec/Fasinex 120 groups respectively, was 97.6% and 94.2% on Day +7, 98.9% and 91% on Day +14 and 98.5% and 92.6% on Day +21. The efficacy of Fasimec' Cattle and Fasimec Sheep was at least equal to that of currently registered products (with the same active ingredients) used to control these parasites.
Publisher: Elsevier BV
Date: 06-2009
Publisher: Elsevier BV
Date: 02-2008
DOI: 10.1016/J.VETPAR.2007.11.002
Abstract: Neospora caninum has recently been shown to be a cause of abortions of sheep in New Zealand. A commercially available enzyme-linked immunosorbent assay (ELISA) was validated for use in sheep with sera from experimentally infected sheep. A cut-off threshold was established that demonstrated sero-conversion between 7 and 14 days post-infection. Higher inocula led to earlier sero-conversion. This ELISA was applied to 640 sera collected from rams across New Zealand and 0.625% (+/-0.61%) (4/640) were shown to be serologically positive. The four positive sera were also demonstrated to be positive by indirect fluorescent antibody test (IFAT). The ELISA evaluated here lends itself more readily to large-scale investigations than IFAT. The low background of N. caninum infection in the New Zealand sheep population suggests that N. caninum abortions could be more easily diagnosed by serological means than in populations with higher background sero-prevalence.
Publisher: JSTOR
Date: 12-1997
DOI: 10.2307/3284361
Publisher: Elsevier BV
Date: 09-2015
DOI: 10.1016/J.VETPAR.2015.08.008
Abstract: A number of countries in the world have reported infections with Neospora caninum in water buffalo (Bubalus bubalis), from Africa to Asia, Europe and South America and recently Australia. In general, clinical manifestations (such as abortion) seem rare, which has raised the prospect that buffalo may be inherently resistant to clinical effects of N. caninum infection. Worldwide, the seroprevalence of N. caninum infection (as a measure of exposure determined by the detection of antibody) in buffalo is high, at approximately 48%. This reported seroprevalence is three or four times higher than that reported from the world's cattle populations, which have collective seroprevalence rates of 16.1% for dairy cattle and 11.5% for beef cattle. However, there is a lack of standardisation in seroprevalence studies and some studies may well under-estimate the true level of infection. Epidemiologic evidence supports post-natal transmission, and in utero transmission has also been demonstrated. The causes for water buffalo to have markedly higher seroprevalence but apparently lower neosporosis abortion rates than cattle warrant further investigation.
Publisher: Elsevier BV
Date: 02-2013
DOI: 10.1016/J.IJPARA.2012.10.022
Abstract: Neospora caninum is regarded as one of the most important infectious causes of abortions in cattle worldwide, yet the global economic impact of the infection has not been established. A systematic review of the economic impact of N. caninum infections/abortions was conducted, searching PubMed with the terms 'cattle' and 'Neospora'. This yielded 769 publications and the abstracts were screened for economically relevant information (e.g. abortion prevalence and risk, serological prevalence). Further analysis was restricted to countries with at least five relevant publications. In total, 99 studies (12.9%) from 10 countries contained data from the beef industry (25 papers (25.3%)) and 72 papers (72.8%) from the dairy industry (with the remaining two papers (2.0%) describing general abortion statistics). The total annual cost of N. caninum infections/abortions was estimated to range from a median US $1.1 million in the New Zealand beef industry to an estimated median total of US $546.3 million impact per annum in the US dairy population. The estimate for the total median N. caninum-related losses exceeded US $1.298 billion per annum, ranging as high as US $2.380 billion. Nearly two-thirds of the losses were incurred by the dairy industry (US $842.9 million). Annual losses on in idual dairy farms were estimated to reach a median of US $1,600.00, while on beef farms these costs amounted to just US $150.00. Pregnant cows and heifers were estimated to incur, on average, a loss due to N. caninum of less than US $20.00 for dairy and less than US $5.00 for beef. These loss estimates, however, rose to ∼US $110.00 and US $40.00, respectively, for N. caninum-infected pregnant dairy and beef cows. This estimate of global losses due to N. caninum, with the identification of clear target markets (countries, as well as cattle industries), should provide an incentive to develop treatment options and/or vaccines.
Publisher: Elsevier BV
Date: 04-2018
DOI: 10.1016/J.PARINT.2017.12.001
Abstract: Fleas are commonly recorded on stray as well as domestic dogs and cats in Hong Kong. Fleas can be a major cause of pruritus in dogs and cats and also vectors of potentially zoonotic bacteria in the genera Rickettsia and Bartonella. Morphological examination of 174 fleas from dogs and cats living in Hong Kong revealed only cat fleas (Ctenocephalides felis). Cytochrome c oxidase subunit 1 gene (cox1) genotyping of 20 randomly selected specimens, revealed three cox1 haplotypes (HK-h1 to HK-h3). The most common haplotype was HK-h1 with 17 specimens (17/20, 85%). HK-h1 was identical to cox1 sequences of fleas in Thailand and Fiji. HK-h1 and HK-h2 form a distinct cat flea cox1 clade previously recognized as the Clade 3. HK-h3 forms a new Clade 6. A multiplex Bartonella and Rickettsia real-time PCR of DNA from 20 C. felis found Bartonella and Rickettsia DNA in three (15%) and ten (50%) C. felis, respectively. DNA sequencing confirmed the presence of R. felis, B. clarridgeiae and Bartonella henselae. This is the first reported study of that kind in Hong Kong, and further work is required to expand the survey of companion animals in the geographical region. The s ling of fleas on domestic cats and dogs in Hong Kong revealed them to be exclusively infested by the cat flea and to be harbouring pathogens of zoonotic potential.
Publisher: Elsevier BV
Date: 1999
DOI: 10.1016/S0166-0934(98)00143-8
Abstract: An electrophoretic immunoblotting technique which was developed recently was evaluated for the identification of serum antibodies against the bovine leukaemia virus core protein p24 by using 167 sera from a bovine leukaemia virus-negative herd, and 144 sera from herds naturally infected with the virus. The sensitivity of the immunoblot was 97.4%, relative to sera which were positive in the polymerase chain reaction and in a commercial EBL-ELISA. The specificity of the immunoblot was 99.4%, for the sera from a cattle herd in which all animals were negative by a commercial EBL-ELISA, and it was 96.7% relative to sera which were negative by the polymerase chain reaction and by the agar gel immunodiffusion test from bovine leukaemia virus-infected cattle herds. A p24-specific ELISA was developed, using a monoclonal anti-p24 antibody for coating microtitre plates, a crude antigen preparation, and a monoclonal anti-bovine IgG-horse radish peroxidase conjugate as components. All reagents were commercially available. While the p24-ELISA worked well with sera from serial bleeds from calves infected experimentally with the bovine leukaemia virus and its sensitivity with sera from the naturally-infected cattle was 96.5%, its specificity was relatively low at 85.0 or 53.3%, respectively for the two negative sera groups.
Publisher: Springer Science and Business Media LLC
Date: 11-01-2022
DOI: 10.1007/S11250-021-03037-Y
Abstract: In mid-2016, the local government of Papua, Indonesia, launched a subsidised program to improve pig farming in the area, with 250 participants. This study aimed to investigate factors associated with enduring participation in pig farming among the program participants. Two years after the commencement of the program, one hundred of the 250 participants were recruited into the study and ided into two groups: participants who continued to engage in pig farming ("remain") and those who had quit pig farming ("quit"). Data were collected from interviews, including personal data and events on the farms between April 2017 and March 2018. Multiple correspondence analysis, followed by a two-step cluster analysis and multivariate regression, was used to explore factors associated with the durability of pig farmings. Results indicated that associated factors included feed and water security, the use of concrete material for the pig house floor, the avoidance of swill feeding, reduced pig mortality, and continued pig husbandry training. This study highlights that a good feeding regimen and effective control of pig diseases should be priority pig husbandry techniques to be extended through training and assistance to improve traditional pig farming in Papua.
Publisher: Elsevier BV
Date: 12-2020
Publisher: MDPI AG
Date: 22-03-2010
DOI: 10.3390/D2030411
Publisher: Public Library of Science (PLoS)
Date: 08-08-2019
Publisher: Elsevier BV
Date: 03-2015
Publisher: Wiley
Date: 25-09-2012
DOI: 10.1002/SMI.2458
Publisher: Wiley
Date: 03-2018
DOI: 10.1136/VR.104468
Abstract: This study investigated the transmission of bovine viral diarrhoea virus (BVDV)-1c from a persistently infected (PI) neonate lamb to naïve sheep and cattle using three treatment groups: four naïve ewes and their five lambs, which were copaddocked with the PI lamb five steers, which were housed in a paddock adjacent to the PI lamb and five steers, which had direct but limited exposure to the PI lamb. Serum s les were collected and tested for BVDV-specific antibodies. Serum s les from the PI lamb, from day of birth to eight weeks of age, were tested for BVDV-specific antibodies and antigen and submitted for quantitative PCR to determine the viral load present at each week of age. Only one lamb from the copaddocked group developed BVDV-specific antibodies following comingling while all the steers in both the cattle treatment groups remained BVDV antibody negative. Quantitative PCR results from the PI lamb showed lower viral loads from day of birth to six weeks of age, compared with the results at seven and eight weeks of age. This may reflect maternal colostral BVDV antibody concentrations in the neonate lamb or other viral properties.
Publisher: Frontiers Media SA
Date: 02-10-2018
Publisher: Elsevier BV
Date: 05-2012
DOI: 10.1016/J.VETPAR.2011.11.032
Abstract: A serological survey for Neospora caninum and Besnoitia besnoiti was carried out in beef and dairy cattle in South Australia. Serum s les of dairy cattle (n=133) from 9 properties and tank milk s les from a further 122 dairy herds were tested. An additional 810 sera from beef cattle from 51 properties were also tested. Testing at the in idual animal level by IDEXX NEOSPORA X2 Ab test ELISA revealed a low prevalence of N. caninum antibodies of only 2.7% (95% CI 1.6-3.7%) sera positive, as did the milk testing that showed 2.5% (95% CI 1.4-3.6%) of tank milks being positive. At the herd level, 29.4% (95% CI 16.9-41.9%) of beef, and 44.4% (95% CI 12.0-76.9%) of dairy cattle herds showed serum antibodies. The highest within-herd prevalence in beef was 20% and 25%in dairy, which explains the low herd prevalence in dairy detected by bulk milk testing. Testing for B. besnoiti antibodies by PrioCHECK(®) Besnoitia Ab 2.0 ELISA initially identified 18.4% (95% CI: 15.8-21.0%) of 869 in idual cattle sera as positive by ELISA at the manufacturer's suggested cut-off threshold (15 PP). Additional tests by immunoblot and IFAT, however, could not confirm any of the ELISA results. The use of a higher (40 PP) threshold in the ELISA is suggested to improve specificity. There is thus no evidence of B. besnoiti infection in South Australian cattle.
Publisher: Elsevier BV
Date: 10-2009
DOI: 10.1016/J.VETPAR.2009.05.019
Abstract: Toxoplasma gondii was isolated from the brain of a young dog for the first time in Australia. The identity of the parasite was confirmed by PCR, Western blotting, electron microscopy and cat bioassay. Genotyping of the isolate (TgDgAu1) was determined by PCR-RFLP markers that showed it to be a Type II strain. Western blotting demonstrated the presence of IgM antibodies to T. gondii suggesting the bitch was probably infected during pregnancy and the T. gondii was transmitted to the pups congenitally. We believe this represents the first description of a natural case of congenital transmission of T. gondii in the dog.
Publisher: Elsevier BV
Date: 12-1994
DOI: 10.1016/0001-706X(94)90012-4
Abstract: An ELISA was used to screen a dog population in Uruguay (Sarandi Del Yi, Durazno District) for the prevalence of specific serum antibodies (IgG, IgA and IgE) to Echinococcus granulosus. The sensitivity (61%) and specificity (97%) of the ELISA were determined using well-defined serum groups. A total of 408 dogs from Sarandi del Yi and environs were screened serologically, and 29.7% (8.6-13.8% for each antibody class) of dogs had positive levels of antibody to E. granulosus. This antibody prevalence (exposure) was significantly higher than the percentage of dogs found to be positive for E. granulosus worms by arecoline purgation (7.6%). This level of exposure to E. granulosus determined by ELISA is considered unacceptable from a public health perspective. Measures will now focus on obtaining data on the true prevalence of current infection in this dog population and on determining the transmission patterns of the disease in this endemic region.
Publisher: SAGE Publications
Date: 22-01-2015
Abstract: Due to relatively high concentrations of immunoglobulins, colostrum has the potential to improve the sensitivity of diagnostic tests for diseases in pigs when compared with serum. It is possible that colostrum could improve the sensitivity of the antibody enzyme-linked immunosorbent assay (ELISA) compared with serum. Colostrum is also essential for piglets, providing protection against infections in the first few weeks and months of life. The sensitivity of 2 commercially available ELISAs, one for the detection of Erysipelothrix rhusiopathiae and the second for Mycoplasma hyopneumoniae antibodies, when used with sow colostrum in comparison with serum was investigated. The correlation of maternal E. rhusiopathiae– and M. hyopneumoniae–specific antibody levels with specific-antibody serum levels in the piglet was also determined. The sensitivity was defined as the proportion of vaccinated sows that were correctly identified as vaccinated at a given cutoff point. The true disease status of the sows with regard to the 2 infections was unknown. Blood and colostrum s les were collected from 20 sows, 10 primiparous and 10 multiparous, and blood s les were also collected from the piglets of each sow, 48–72 hr post-farrowing. The sensitivities of both ELISAs were significantly improved when using colostrum compared with serum. Sow serum and colostrum optical density (OD) values were significantly correlated. The mean sow OD values for serum for E. rhusiopathiae and M. hyopneumoniae and colostrum for E. rhusiopathiae were significantly correlated with piglet serum OD levels. If the improved sensitivity of colostrum can be demonstrated in infected animals, this will increase the ability of the test to identify infected animals using both in idual and pooled colostrum. Testing serum and/or colostrum using ELISA can be useful predictors of piglet disease–specific OD values.
Publisher: Elsevier BV
Date: 04-1999
DOI: 10.1016/S0378-1135(98)00311-3
Abstract: Three hundred and forty-one sera from cattle in Western Australia and 106 sera from Mycobacterium paratuberculosis faecal culture positive cattle were used to evaluate the performance of two absorbed enzyme-linked immunosorbent assays (ELISA) (one locally produced, the other a commercial test) and a complement fixation test (CFT) for the detection of Johne's disease in cattle. The diagnostic sensitivity (47.2%) of the local ELISA was significantly higher than that of the commercial ELISA (31.1%), and significantly higher than that for the complement fixation test (17.9%) and immunoblot (20.8%). Diagnostic specificity for the two ELISAs was 99.7% and 97.9% and similar for CFT and immunoblot (97.1% and 97.7%, respectively). The diagnostic sensitivity rose for both ELISAs and the CFT as the number of M. paratuberculosis isolated from the faeces increased. The ELISA antigen was characterised by polyacrylamide gel electrophoresis and electrophoretic immunoblotting and was found to consist mostly of a carbohydrate-type macromolecule of 32-42 kDa. This macromolecule was identified as lipoarabinomannan (LAM) by using a LAM-specific monoclonal antibody in immunoblots and purified LAM in absorption experiments. By applying more complex antigen preparations in immunoblots, serum antibodies against proteins of 47, 37, 30, 24 and 21 kDa, and against the 32-42 kDa carbohydrate component were frequently found in infected cattle, and of these the 47 kDa protein and the 32-42 kDa antigen were immuno-dominant. Pre-absorption of the sera with M. phlei sonicate indicated that the protein antigens contributed markedly to non-specific serological cross-reactions, while the 32-42 kDa non-protein macromolecule appeared to be specific.
Publisher: American Society for Microbiology
Date: 2013
DOI: 10.1128/CVI.00225-12
Abstract: Infection of cattle with Neospora caninum may result in abortion or the birth of a congenitally infected calf. Vaccination with live N. caninum protects against experimental infection of cattle and mice, and the naturally attenuated Nc-Nowra strain of N. caninum is of particular interest as a potential vaccine candidate. Vaccination of heifers prior to breeding with live Nc-Nowra tachyzoites by either the subcutaneous or the intravenous route reduced the rate of abortion and the presence of the parasite in calves as determined by PCR and serology after infection of cows with a virulent isolate. Protected fractions were 55.6% to 85.2% depending on the route of vaccination and growth conditions of the vaccine strain, with cryopreserved Nc-Nowra tachyzoites being less effective, with a 25.9% protected fraction. Vaccination appeared to reduce the rate of pregnancy after artificial insemination in some groups compared to nonvaccinated, nonchallenged controls. One animal that was vaccinated but not challenged experienced an abortion, but Nc-Nowra could not be detected in any of the cows in this group or their progeny. This study confirms that live vaccination can be an effective method of preventing neosporosis in cattle and yet highlights the technical hurdle of preservation of live parasites that must be overcome for a vaccine to be commercially successful.
Publisher: Wiley
Date: 26-06-2014
DOI: 10.1111/AVJ.12188
Abstract: The aims of this study were to evaluate a commercially available ELISA for the detection of bovine viral diarrhoea virus (BVDV)-specific antibodies in in idual milk compared with in idual serum s les, and in bulk milk s les compared with within-herd antibody prevalence and bulk milk quantitative reverse transcription polymerase chain reaction (qRT-PCR) results. Paired in idual serum and in idual milk s les were collected from 125 lactating cows and tested by ELISA 96 bulk milk s les were also tested. Within-herd antibody prevalence was calculated based on milk ELISA results for 25 in idual cows in each herd. Additionally, 167 bulk milk s les were tested for BVDV-specific antibodies by ELISA and for the presence of BVDV by qRT-PCR to establish the correlation between antibody result and virus presence. Good agreement was observed between in idual milk and serum results (Kappa = 0.865). The ELISA was observed to detect BVDV-specific antibodies in in idual milk s les with a relative sensitivity of 96.6% and specificity of 89.2%. The bulk milk s les revealed a strong (r(2) = 0.95) relationship between the ELISA result and the within-herd antibody prevalence. The proportion of herds that tested positive by bulk milk qRT-PCR increased as the bulk milk antibody S/P ratio increased. Commercially available ELISA testing of in idual and bulk milk s les is an appropriate alternative to serum testing with good test performance in these s les. Determining a threshold for the detection of herds containing active BVD infection by testing bulk milk is a novel use for an antibody ELISA kit and provides more practical, relevant test results.
Publisher: Elsevier BV
Date: 09-1996
DOI: 10.1016/0166-0934(96)02065-4
Abstract: Six antigen preparations of bovine leukemia virus, including affinity-purified glycoprotein gp51, gradient-purified fetal lamb kidney-bovine leukemia virus antigen, and four crude antigens, were used in combination with several groups of cattle sera, for the evaluation of electrophoretic immunoblotting as a serological test method. Sera (89) from cattle naturally-infected with bovine leukosis virus, a panel of reference sera from infected and uninfected cattle (18), and serial bleedings from experimentally-infected cows (4) were used. Major differences between the six antigen preparations were observed in their reactivity with the various sera. The immunological variabilities of these antigens were confirmed further by their reactions with a gp51-specific monoclonal antibody. The known immunodominant gp51 failed as a reliable indicator for the serological status of the sera in blots when compared to the results on the same sera, two gp51-specific ELISAs and the agar gel immunodiffusion test were used as reference tests. There was a lack of staining of gp51 antigen by many sera, probably due to the labile nature of the gp51 molecule. On the other hand, non-specific staining in the gp51 region appeared with high frequency in some antigens. Antibody staining of the internal viral protein p24 correlated well with the results of the three reference tests. Other bands stained infrequently and were of no diagnostic value.
Publisher: Elsevier BV
Date: 2021
Publisher: Informa UK Limited
Date: 04-01-1997
DOI: 10.1080/00480169.1997.35995
Abstract: Two antigen preparations, the routinely used Brucella ovis sodium dodecylsulfate-mercapto ethanol extract and a B. ovis Triton X-114-derived detergent-rich phase, were compared under standard conditions for their use in electrophoretic immunoblotting for confirmafory, serological testing for B. ovis infections, by using 88 sera from ram flocks with a history of freedom from B. ovis infections, 80 sera from chronically infected rams, which were shedding B. ovis in their semen at the time of s ling, and 104 sera from a naturally infected ram flock. Blots with the detergent-rich phase as antigen gave better correlation with the serological results from naturally infected rams, exhibited no non-specific staining with sera from the negative group, gave clearer visualisation of specific bands for positive sera, and were equally sensitive when compared to the standard antigen for sera from chronically infected rams.
Publisher: Informa UK Limited
Date: 08-1998
DOI: 10.1080/00480169.1998.36078
Abstract: To evaluate commercially available enzyme-linked immunosorbent assays (ELISAs) and the polymerase chain reaction (PCR) for their ability to detect antibodies against or nucleic acid of the bovine leukaemia virus (BLV), the causal agent of enzootic bovine leukosis (EBL), and to assess their usefulness in a national eradication programme. Eighty-two well-defined sera (including 18 from an OIE reference laboratory) and 399 field sera from New Zealand cattle were tested in five ELISAs and the results compared with the agar gel immunodiffusion (AGID) test and electrophoretic immunoblotting (EIB) results. A polymerase chain reaction-based technique, which could detect BLV-RNA and proviral-DNA, was also evaluated on a subs le of the field cases. Two commercial ELISAs classified 99% of the defined sera correctly, with the other three ranging in their correct classification between 88% and 95%. The ELISAs agreed in their general classification on the majority of the 399 blood s les (91.7%), and with the AGID for more than 95 % of the sera. In a dilution series of the international reference serum E4, the highest dilution with a positive (or suspicious) result ranged from 1:80 to 1:5120. A dilution series of 202 field positive s les tested in the preferred ELISA detected 98% of positive sera at a 15 and 1: 10 dilution, reducing to 78% at a 1:80 dilution of the sera. Agreement between serological tests and PCR was poor, mainly due to failure of the PCR to detect a number of serologically positive animals. ELISA tests detected about 10% more reactors than the AGID and the EIB combined. Some ELISA-positive animals were not detected by PCR, raising doubts about the usefulness of PCR-based technology in EBL eradication programmes.
Publisher: Elsevier BV
Date: 02-2014
DOI: 10.1016/J.TVJL.2013.07.024
Abstract: Bovine viral diarrhoea virus (BVDV) is the most prevalent infectious disease of cattle. It causes financial losses from a variety of clinical manifestations and is the subject of a number of mitigation and eradication schemes around the world. The pathogenesis of BVDV infection is complex, with infection pre- and post-gestation leading to different outcomes. Infection of the dam during gestation results in fetal infection, which may lead to embryonic death, teratogenic effects or the birth of persistently infected (PI) calves. PI animals shed BVDV in their excretions and secretions throughout life and are the primary route of transmission of the virus. These animals can usually be readily detected by virus or viral antigen detection assays (RT-PCR, ELISA), except in the immediate post-natal period where colostral antibodies may mask virus presence. PI calves in utero (the 'Trojan cow' scenario) currently defy detection with available diagnostic tests, although dams carrying PI calves have been shown to have higher antibody levels than seropositive cows carrying non-PI calves. Acute infection with BVDV results in transient viraemia prior to seroconversion and can lead to reproductive dysfunction and immunosuppression leading to an increased incidence of secondary disease. Antibody assays readily detect virus exposure at the in idual level and can also be used in pooled s les (serum and milk) to determine herd exposure or immunity. Diagnostic tests can be used to diagnose clinical cases, establish disease prevalence in groups and detect apparently normal but persistently infected animals. This review outlines the pathogenesis and pathology of BVD viral infection and uses this knowledge to select the best diagnostic tests for clinical diagnosis, monitoring, control and eradication efforts. Test methods, types of s les and problems areas of BVDV diagnosis are discussed.
Publisher: Elsevier BV
Date: 05-2010
DOI: 10.1016/J.VETPAR.2010.01.030
Abstract: Presence of Neospora caninum DNA was detected in the brain and spinal cord of an adult Merino sheep suspected of dying with acute non-suppurative meningoencephalitis and mild to moderate non-suppurative myelitis. The most severe neurological lesions were found in the midbrain at the rostral coliculi with moderate to severe multifocal vasculitis and gliosis. As this was the first known occurrence of cerebral disease in sheep in Australia caused by N. caninum, we surveyed sera from five sheep properties in New South Wales (NSW) to obtain information on the likely prevalence of N. caninum infection in NSW sheep flocks. Serology using a commercial indirect enzyme-linked immunosorbent assay (ELISA) revealed no N. caninum antibody-positive sheep (n=184). However an observed prevalence for N. caninum antibodies using a commercially available competitive ELISA was 2.2% (5/232). We conclude that although the diagnosis of fatal ovine cerebral neosporosis is of importance to our surveillance program for transmissible spongiform encephalopathy (TSE) exclusion, sheep in NSW are not commonly infected with N. caninum and this species likely plays only a minor role in the life cycle of this parasite in Australia.
Publisher: Springer Science and Business Media LLC
Date: 30-11-2015
Publisher: Elsevier BV
Date: 07-2002
DOI: 10.1016/S0304-4017(02)00095-X
Abstract: To validate an enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies against liver fluke (Fasciola hepatica) in sheep and cattle sera. Gold-standard sera from sheep and cattle of known infection status, i.e. sera from non-infected animals and from animals known to be infected with F. hepatica were assayed with a commercially available ELISA and results analysed by ROC analysis. The ROC analysis suggested cut-offs that were considerably lower than those suggested by the manufacturer, yet the ELISA performed with high sensitivity and specificity, 98 to 100%, respectively for sheep and cattle sera. For bovine sera, particularly good discrimination between positive and negative sera was observed. Infection in experimentally infested animals could be demonstrated 7-8 weeks earlier than with classical parasitological techniques. The analysis of the ELISA's performance demonstrated high sensitivity and specificity. ROC analyses optimised the cut-off point suggested by the manufacturer of the commercial diagnostic assay. Diagnosis of infection with F. hepatica was achieved much earlier than is possible with current parasitological techniques. This could help with the control of fasciolosis, enabling treatment before clinical manifestation of the disease.
Publisher: Elsevier BV
Date: 11-2008
DOI: 10.1016/J.VACCINE.2008.08.043
Abstract: Abortion, resulting from infections by the parasite Neospora caninum, is a major cause of economic loss to both the dairy and beef industries of cattle-producing countries of the world. Vaccination as a means of preventing abortion and/or infection represents a viable control strategy indeed a commercial vaccine is available in some countries, albeit of unknown efficacy. The commercial vaccine is based on inactivated tachyzoites of N. caninum but other approaches based on lysates and recombinant antigens of N. caninum may also be feasible. In this study we have used an immunisation/challenge model of transplacental transmission, based on the Qs mouse with an Nc-Liverpool challenge, to investigate the vaccine potential of a number of formulations based on four recombinant proteins of N. caninum (GRA1, GRA2, MIC10, and p24B). All formulations studied were immunogenic in the mouse when assessed by ELISA using sonicated tachyzoite antigen as the target antigen. In one experiment, a mixture of MIC10 and p24B produced partial protection against transplacental transmission of N. caninum in this mouse model in contrast a live infection of tachyzoites of NC-Nowra given before pregnancy always induces very high levels of protective immunity. The field of vaccines against Neospora-associated abortion in cattle is discussed.
Publisher: Wiley
Date: 17-06-2014
DOI: 10.1111/AVJ.12208
Abstract: Acute infection with bovine viral diarrhoea virus (BVDV) usually causes only mild clinical disease in cattle, but infection of animals of breeding age can result in immune suppression (resulting in an increased incidence and severity of secondary disease) and decreased reproductive performance. If infection occurs during pregnancy, the virus may cross the placenta and either cause abortion, establish immunotolerance and persistent infection (PI) in the fetus or cause congenital deformities. These outcomes depend on the stage of pregnancy at the time of infection. BVDV is recognised as a disease of significant financial impact in a number of countries. As a result, national and regional BVDV control programs are now in place in several regions around the world. In Europe, these programs largely rely on the identification and removal of the PI animals, whereas vaccination has tended to be the chosen method of control in the United States. BVDV is endemic in Australian cattle populations, with more than 80% of herds surveyed showing some level of exposure to the pathogen. The cost to the national industry is estimated to be AUD57.9 million annually. This review identifies and discusses the challenges to BVDV control in Australia, including farmer attitudes, herd size, sheep as a potential reservoir host and diagnostic capabilities. We conclude that systematic BVDV control in Australia is, or soon will be, an option however, detailed cost-benefit analyses will need to be undertaken.
Publisher: Elsevier BV
Date: 04-2022
Publisher: Elsevier BV
Date: 04-2017
Publisher: Elsevier BV
Date: 03-2000
DOI: 10.1016/S0169-4758(99)01604-X
Abstract: Neospora caninum is an apicomplexan protozoan that has become the focus of significant research attention worldwide. This organism infects a range of host species, including dogs, from which it was originally reported in 1984, but it is most important as a major cause of bovine abortion. As a result of the global importance of N. caninum, researchers have developed a number of serological tests to investigate the epidemiology of infection and disease. In this article, Robert Atkinson, Peter Harper, Michael Reichel and John Ellis consider progress made in the serodiagnosis of N. caninum.
Publisher: Springer Science and Business Media LLC
Date: 17-09-2015
DOI: 10.1007/S11250-015-0913-5
Abstract: Village pig husbandry is an important part of livestock production in Papua Province, Eastern Indonesia. However, high level of disease and mortality constrains production. The aim of this study was to investigate the prevalence of the selected pathogens in village pigs in the Jayawijaya Region of Papua Province, Indonesia. Two studies were conducted: Study 1 determined the prevalence of selected pathogens in dead or moribund pigs sent to the main local market for sale. Study 2 recorded the prevalence of the selected pathogens, on pig farms in the Subdistrict of Wamena that had not recorded a case of pig mortality during the duration of Study 1. Blood s les of in iduals from both groups were tested for CSF antigen and antibody, as well as antibody against PCV2. Organs with evident pathological changes from Study 1 and tonsilar swabs from Study 2 were subjected to bacteriological culture and identification of Streptococcus suis and Streptococcus zooepidemicus. Faecal s les from both studies were examined for eggs of strongyle parasites, Trichuris suis, Ascaris suum, Strongyloides ransomi and coccidia. The main infections in both studies were CSF, PCV2 and strongyle parasites, but prevalence was higher in Study 1 (P < 0.05). T. suis and S. zooepidemicus were prevalent in pigs in Study 1, but rare in healthy pigs (P < 0.05). Infections with coccidia, A. suum and S. ransomi were common but did not differ between groups (P < 0.05), with S. suis infections uncommon in both studies. This suggests that infections with CSF, PCV2, strongyle and T. suis are important pathogens in village pig farms in Jayawijaya. Local pig husbandry practices, such as confining pigs and heat-treating pig feeds, may be practical solutions to help minimize infection in village pigs in Jayawijaya.
Publisher: Elsevier BV
Date: 12-1989
Publisher: MDPI AG
Date: 22-01-2018
Publisher: Elsevier BV
Date: 05-2002
DOI: 10.1016/S0167-5877(02)00011-9
Abstract: A 600-cow New Zealand dairy herd experienced an abortion storm in 1997 and was monitored (blood s ling at about 3-month intervals) from May 1997 until January 1999. Abortion risk reached 9% in 1997 and was highest in heifers at 19%. The abortion risk decreased in 1998 to 3.2% (still somewhat higher than during the years prior to the outbreak). The serological reaction pattern for Neospora caninum showed an association with abortion risk only around the time of the 1997 outbreak when seropositive cows were 4.2 times more likely to abort than negative ones. Over the whole study period, only 27% of cows that were s led on all nine visits always tested negative. Offspring from dams which had positive tests for Neospora caninum were 2.4 times more likely to abort than those from dams testing consistently negative. Controlling for age and breed, seropositive cows produced more milk than those that were consistently negative. Infection might have been present endemically within this herd prior to the epidemic, but in 1997 an additional factor appeared to have triggered the outbreak.
Publisher: Informa UK Limited
Date: 06-1998
DOI: 10.1080/00480169.1998.36069
Abstract: A 13-week-old female boxer pup was found to be suffering from rigidity of the left hindleg. Antibiotic and anti-inflammatory treatment over a 3-week period failed to improve the condition and the pup was humanely killed. Serological examination for Neospora antibodies was carried out by the indirect fluorescent antibody test and for Toxoplasma gondii antibodies with a latex agglutination test. A variety of tissues were examined histologically, and the central nervous system by immunohistochemistry and the polymerase chain reaction. The IFAT for anti-Neospora antibodies showed a titre of 1:51 200 in the clinically affected pup while the latex agglutination test for Toxoplasma antibodies was negative. The dam and one of two tested litter-mates had anti-Neospora IFAT titres of 1:1600, the other litter mate was negative. All three were not clinically affected. Histological, immunohistochemical and polymerase chain reaction examinations of the affected pup confirmed the diagnosis of Neospora infection. In the live animal, serological examination is thought to be the most useful specific test. Post-mortem examination by traditional histology, immunohistochemistry and the polymerase chain reaction confirmed the diagnosis. The case is discussed in the context of present knowledge about Neospora infection in New Zealand.
Publisher: Springer Science and Business Media LLC
Date: 08-2013
Publisher: Cambridge University Press (CUP)
Date: 25-03-2014
DOI: 10.1017/S0031182014000158
Abstract: Recent work has highlighted and enumerated the economic annual losses due to Neospora caninum abortions worldwide, which should provide strong motivation for the control of bovine neosporosis. However, with the recent withdrawal from sale of the only commercially available vaccine, control options for N. caninum have become more restricted. While researchers continue to work on developing alternative efficacious vaccines, what are the control options presently available for the cattle industries? At the practical level, recommendations for ‘Test-and-cull’, or ‘not breeding from seropositive dams’ stand diametrically opposed to alternative options put forward that suggest a primary producer is better advised to keep those cows in the herd that are already seropositive, i.e. assumed to be chronically infected, and indeed those that have already aborted once. Treatment with a coccidiostat has been recommended as the only economically viable option, yet no such treatment has gained official, regulatory approval. Dogs are central to the life cycle of N. caninum and have repeatedly been associated with infection and abortions in cattle by epidemiological studies. Knowledge and understanding of that pivotal role should be able to be put to use in control programmes. The present review canvasses the relevant literature for evidence for control options for N. caninum (some of them proven, many not) and assesses them in the light of the authors’ knowledge and experience with control of N. caninum .
Publisher: Springer Science and Business Media LLC
Date: 17-01-2013
DOI: 10.1007/S11250-013-0353-Z
Abstract: This work estimates the economic losses due to Neospora abortions in the humid p a region of Argentina.The total dairy and beef cattle population at risk of abortion is 1,771,326 and 9,726,684 head, respectively. In dairy cattle, there was an 8 % risk of experiencing abortion due to a variety of causes, but 16.5 % of them were due to Neospora caninum. The economic losses were estimated at US$1,415 (1,400-1,431) per abortion, which equates to a total loss of US$33,097,221 (15,622,600-119,349,693) for the dairy industry at the humid p a region of Argentina. In beef cattle, the overall risk of abortion was estimated to be 4.5 % for all pregnancies,whereas 6.7 % are specifically due to N. caninum, with an economic loss of US$440 (range, 150-730) per abortion.This amounts to an annual loss to the beef industry of US$12,903,440 (range, 1,130,700-42,070,630) in the same area. The results of this study show that Neospora infections and thus abortions cause severe economic impacts in the dairy and beef industries in the humid p a region of Argentina, which is one the most important areas of cattle production in the world [corrected].
Publisher: Mary Ann Liebert Inc
Date: 06-2003
DOI: 10.1089/104454903767650667
Abstract: Parasitic organisms remain the scourge of the developed and underdeveloped worlds. Malaria, schistosomiasis, leishmaniasis, and trypanosomiasis, for ex le, still result in a large number of human deaths each year worldwide, while drug resistance among nematodes still poses a major problem to the livestock industries. Genome projects involving parasitic organisms are now abundant, and technologies for the investigations of the parasite transcriptome and proteome are well established. There is no doubt the era of the "omics" is with parasitology, and current trends in the discipline are addressing fundamental biological questions that can make best use of the new technologies, as well as the vast amount of new data being generated. Will this become the "golden age of molecular parasitology," leading to the control of parasitic diseases that have plagued mankind for hundreds of years? The primary aim of this paper is to review advances in the general area of parasite genomics, and to outline where the application of "omics" technologies can and have impacted on the development of new control methods for parasitic organisms.
Publisher: Informa UK Limited
Date: 10-2000
DOI: 10.1080/00480169.2000.36182
Abstract: To estimate the prevalence of Neospora infection in a s le of New Zealand beef cattle. The prevalence of Neospora caninum infection in New Zealand beef cattle was estimated by collecting blood at slaughter from 499 beef cattle from 40 different farms at 2 slaughter plants in the North Island and 1 in the lower South Island . Sera were tested using an ELISA against Neospora tachyzoite antigen. The prevalence of seropositive cattle was 2.5% (n=120), 3.6% (n=166) and 2.3% (n=213) at the plants surveyed, the overall prevalence being 2.8%. The serologically positive cattle came from 9 farms, 3 of which had more than 1 positive animal. The highest prevalence recorded amongst animals from 1 farm was 4/13 (31%), in a group of young steers. Neosporosis appears to be present at a lower level in the New Zealand beef cattle population than in the New Zealand dairy cattle population. Nevertheless, from the high seroprevalence evident amongst young cattle on 1 farm, we suggest that Neospora may be a cause of infertility in beef cattle in this country.
Publisher: Elsevier BV
Date: 10-1999
DOI: 10.1016/S0020-7519(99)00104-6
Abstract: Serological methods developed to detect Neospora caninum specific bovine antibodies were compared using sera from an abortion outbreak on a dairy farm in New Zealand. These methods included four ELISAs, IFAT and immunoblot. The abortions (n = 16) on the farm were restricted to one of two groups of the herd which consisted of 194 adult dairy cows. All ELISAs, IFAT and immunoblot (applying stringent cut-off levels) revealed a statistically significant association between seropositivity and abortion among the adult cows from the afflicted group 1. The strength of this association varied between different tests, and different seroprevalences were determined for various animal groups. Among the different ELISAs, the strength of the relationship between single test results was characterised by a considerable variation in the determinants of correlation. Discrepancies in positive-negative classification between the two commercial ELISAs and one of the in-house ELISAs were due mainly to differences in the cut-off selection.
Publisher: Elsevier BV
Date: 08-2008
DOI: 10.1016/J.MCP.2008.03.001
Abstract: The development of a novel nested polymerase chain reaction is described and used for detecting the presence of Neospora caninum and Hammondia heydorni DNA in DNA extracted from feral rodent tissues. A unique strategy was used for design of an assay that could be adapted for detecting DNA from more than one member of Toxoplasmatinae simultaneously with a minimal number of additional steps. The level of sensitivity described for this assay is comparable to real time-PCR and other nested PCR assays. Twenty-eight of 104 feral mice tested positive for N. caninum in at least one tissue (the brain, heart or liver) studied. In this study, eight instances are reported where the brain tested negative to N. caninum while at least one other tissue was positive. This suggests that prior studies, which screened only the brain, describe prevalence levels that are under-represented. None of 54 mouse brains tested positive for H. heydorni DNA. This suggests that mice are rarely infected by H. heydorni although this hypothesis needs to be explored further. Data obtained in the current study suggest that N. caninum is a common parasite of feral rodents which may be important in the epidemiology of the disease.
Publisher: Springer Science and Business Media LLC
Date: 12-05-2016
Location: Germany
Location: Australia
No related grants have been discovered for Michael Reichel.