ORCID Profile
0000-0003-4277-9983
Current Organisations
European College of Veterinary Public Health
,
Universität Zürich
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Publisher: Elsevier BV
Date: 02-2017
DOI: 10.1016/J.VETPAR.2016.12.007
Abstract: The prevalence of anthelmintic resistance has increased in recent years, as a result of the extensive use of anthelmintic drugs to reduce the infection of parasitic worms in livestock. In order to detect the resistance, the number of parasite eggs in animal faeces is counted. Typically a subs le of the diluted faeces is examined, and the mean egg counts from both untreated and treated animals are compared. However, the conventional method ignores the variabilities introduced by the counting process and by different infection levels across animals. In addition, there can be extra zero counts, which arise as a result of the unexposed animals in an infected population or animals. In this paper, we propose the zero-inflated Bayesian hierarchical models to estimate the reduction in faecal egg counts. The simulation study compares the Bayesian models with the conventional faecal egg count reduction test and other methods such as bootstrap and quasi-Poisson regression. The results show the Bayesian models are more robust and they perform well in terms of both the bias and the coverage. We further illustrate the advantages of our proposed model using a case study about the anthelmintic resistance in Swedish sheep flocks.
Publisher: Elsevier BV
Date: 2014
Abstract: Foodborne diseases (FBDs) are a major cause of morbidity and mortality in the human population. Accurate information on the burden of FBDs is needed to inform policy makers and allocate appropriate resources for food safety control and intervention. Consequently, in 2006 the WHO launched an initiative to estimate the global burden of FBDs in terms of Disability Adjusted Life Years (DALYs). This review gives an update of the progress on evaluating the burden of foodborne parasitic diseases that has been generated by this study. Results to date indicate that parasitic diseases that can be transmitted through food make a substantial contribution to the global burden of disease.
Publisher: Public Library of Science (PLoS)
Date: 23-12-2015
Publisher: American Veterinary Medical Association (AVMA)
Date: 03-2018
Abstract: OBJECTIVE To characterize delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) features of healthy hyaline cartilage of the distal interphalangeal joint (DIPJ) of horses, to determine whether dGEMRIC can be used to differentiate various stages of naturally occurring osteoarthritis of the DIPJ, and to correlate relaxation times determined by dGEMRIC with the glycosaminoglycan concentration, water content, and macroscopic and histologic findings of hyaline cartilage of DIPJs with and without osteoarthritis. SAMPLE 1 cadaveric forelimb DIPJ from each of 12 adult warmblood horses. PROCEDURES T1-weighted cartilage relaxation times were obtained for predetermined sites of the DIPJ before (T1 preGd ) and after (T1 postGd ) intra-articular gadolinium administration. Corresponding cartilage sites underwent macroscopic, histologic, and immunohistochemical evaluation, and cartilage glycosaminoglycan concentration and water content were determined. Median T1 preGd and T1 postGd were correlated with macroscopic, histologic, and biochemical data. Mixed generalized linear models were created to evaluate the effects of cartilage site, articular surface, and macroscopic and histologic scores on relaxation times. RESULTS 122 cartilage specimens were analyzed. Median T1 postGd was lower than the median T1 preGd for normal and diseased cartilage. Both T1 preGd and T1 postGd were correlated with macroscopic and histologic scores, whereby T1 preGd increased and T1 postGd decreased as osteoarthritis progressed. There was topographic variation of T1 preGd and T1 postGd within the DIPJ. Cartilage glycosaminoglycan concentration and water content were significantly correlated with T1 preGd and macroscopic and histologic scores but were not correlated with T1 postGd . CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that dGEMRIC relaxation times varied for DIPJs with various degrees of osteoarthritis. These findings may help facilitate early detection of osteoarthritis.
Publisher: Wiley
Date: 05-2013
DOI: 10.1136/VR.F3308
Publisher: O.I.E (World Organisation for Animal Health)
Date: 08-2021
Publisher: Cambridge University Press (CUP)
Date: 16-07-2015
DOI: 10.1017/S0022149X15000395
Abstract: Canids, particularly dogs, constitute the major source of cystic echinococcosis (CE) infection to humans, with the majority of cases being caused by Echinococcus granulosus (G1 genotype). Canine echinococcosis is an asymptomatic disease caused by adult tapeworms of E. granulosus sensu lato (s.l.). Information on the population structure and genetic variation of adult E. granulosus is limited. Using sequenced data of the mitochondrial cytochrome c oxidase subunit 1 ( cox1 ) we examined the genetic ersity and population structure of adult tapeworms of E. granulosus (G1 genotype) from canid definitive hosts originating from various geographical regions and compared it to that reported for the larval metacestode stage from sheep and human hosts. Echinococcus granulosus (s.s) was identified from adult tapeworm isolates from Kenya, Libya, Tunisia, Australia, China, Kazakhstan, United Kingdom and Peru, including the first known molecular confirmation from Gaza and the Falkland Islands. Haplotype analysis showed a star-shaped network with a centrally positioned common haplotype previously described for the metacestode stage from sheep and humans, and the neutrality indices indicated population expansion. Low Fst values suggested that populations of adult E. granulosus were not genetically differentiated. Haplotype and nucleotide ersities for E. granulosus isolates from sheep and human origin were twice as high as those reported from canid hosts. This may be related to self-fertilization of E. granulosus and/or to the longevity of the parasite in the respective intermediate and definitive hosts. Improved nuclear single loci are required to investigate the discrepancies in genetic variation seen in this study.
Publisher: Elsevier BV
Date: 08-2018
Publisher: Public Library of Science (PLoS)
Date: 03-12-2015
Publisher: Elsevier
Date: 2017
DOI: 10.1016/BS.APAR.2016.11.001
Abstract: Alveolar echinococcosis (AE) and cystic echinococcosis (CE) are severe helminthic zoonoses. Echinococcus multilocularis (causative agent of AE) is widely distributed in the northern hemisphere where it is typically maintained in a wild animal cycle including canids as definitive hosts and rodents as intermediate hosts. The species Echinococcus granulosus, Echinococcus ortleppi, Echinococcus canadensis and Echinococcus intermedius are the causative agents of CE with a worldwide distribution and a highly variable human disease burden in the different endemic areas depending upon human behavioural risk factors, the ersity and ecology of animal host assemblages and the genetic ersity within Echinococcus species which differ in their zoonotic potential and pathogenicity. Both AE and CE are regarded as neglected zoonoses, with a higher overall burden of disease for CE due to its global distribution and high regional prevalence, but a higher pathogenicity and case fatality rate for AE, especially in Asia. Over the past two decades, numerous studies have addressed the epidemiology and distribution of these Echinococcus species worldwide, resulting in better-defined boundaries of the endemic areas. This chapter presents the global distribution of Echinococcus species and human AE and CE in maps and summarizes the global data on host assemblages, transmission, prevalence in animal definitive hosts, incidence in people and molecular epidemiology.
Publisher: Springer Science and Business Media LLC
Date: 18-04-2019
Publisher: Elsevier BV
Date: 06-2022
Publisher: Elsevier BV
Date: 07-2012
DOI: 10.1016/J.ACTATROPICA.2012.02.066
Abstract: This paper is based on the experience of the authors, with the aim to define the challenges for Echinococcus granulosus (E.g./CE) diagnosis and control for those countries that may now or in the future be contemplating control of hydatid disease. A variety of methods are available for diagnosis in humans but a universal gold standard is lacking. Diagnosis in definitive hosts can avoid necropsy by the use of methods such as coproantigen detection but test performance is variable between populations. A sylvatic cycle adds challenges in some countries and the epidemiology of the parasite in these hosts is poorly understood. Control by solely administering praziquantel to dogs is not effective in developing countries where the disease is endemic. Additional avenues to pursue include the instigation of participatory planning, use of an existing vaccination for intermediate hosts and development of a vaccine and long-acting anthelmitic implants for definitive hosts. Promoting public acceptance of control of the dog population by humane euthanasia and reduced reproduction is also essential.
Publisher: Public Library of Science (PLoS)
Date: 06-06-2019
Publisher: Wiley
Date: 10-2013
DOI: 10.1136/VR.F6079
Publisher: Springer Science and Business Media LLC
Date: 07-05-2020
DOI: 10.1186/S13071-020-04095-1
Abstract: Taenia saginata is an important zoonotic parasite, causing taeniosis in humans and cysticercosis in bovines, the latter being a significant concern for the global beef industry. Many countries in East, Southeast and South Asia are experiencing rapid economic growth, and an increasing number of people in these countries are dependent on the livestock industry. Currently, however, an overview of the prevalence of T. saginata in this region is lacking. In this review, we analysed the available literature on T. saginata taeniosis and bovine cysticercosis for East, Southeast and South Asia. A systematic review was conducted, based on both published and grey literature. Articles published between 1990 and 2017 were mined for information on the occurrence, prevalence, and geographical distribution of T. saginata taeniosis and bovine cysticercosis in East, Southeast and South Asia. The presence of T. saginata was described in 15 of 27 countries of the region, including Afghanistan, Cambodia, China, India, Indonesia, Japan, Lao PDR, Malaysia, Mongolia, Nepal, Pakistan, Philippines, South Korea, Thailand and Vietnam. The only country that reported an absence of T. saginata is Japan, although sporadic reports of imported cases and unconfirmed reports of autochthonous infections were identified. Nationwide surveys of taeniosis with systematic s le collection and high s le numbers were available for Cambodia, China, Lao PDR, and South Korea, although speciation of Taenia was not always performed. Regional prevalence of taeniosis and bovine cysticercosis in endemic regions ranged between 0.02–42.6%, and 0.76–46.7%, respectively. However, data for bovine cysticercosis were only available for five countries (Japan, Lao PDR, Mongolia, Pakistan and Vietnam). The data indicate a widespread occurrence of T. saginata throughout East, Southeast and South Asia. Identification of Taenia spp. in human infections was frequently not performed, leading to gaps in knowledge about the distribution of human tapeworm infections, mainly in regions where different human Taenia species co-occur. A high prevalence of T. saginata taeniosis and bovine cysticercosis may reflect insufficiencies in sanitation, limited health education standards, and insufficient food safety measures. Therefore, there is a need to improve local surveillance, notification, and overall control systems.
Publisher: Public Library of Science (PLoS)
Date: 14-09-2017
Publisher: Cold Spring Harbor Laboratory
Date: 10-05-2022
DOI: 10.1101/2022.05.10.22274867
Abstract: Foodborne and zoonotic diseases such as brucellosis present many challenges to public health and economic welfare. Increasingly, researchers and public health institutes use disability-adjusted life years (DALYs) to generate a comprehensive comparison of the population health impact of these conditions. DALYs calculations, however, entail a number of methodological choices and assumptions, with data gaps and uncertainties to accommodate. The following review identifies existing brucellosis burden studies and analyzes their methodological choices, assumptions, and uncertainties. The review supports the Global Burden of Animal Diseases programme in the development of a systematic methodology to describe the impact of animal diseases on society, including human health. A systematic search for brucellosis burden calculations was conducted in pre-selected international and grey literature databases. Using a standardized reporting framework, we evaluated each estimate on a variety of key methodological assumptions necessary to compute a DALY. Thirteen studies satisfied the inclusion criteria (human brucellosis and quantification of DALYs). One study reported estimates at the global level, the rest were national or subnational assessments. Data regarding different methodological choices were extracted, including detailed assessments of the adopted disease models. Most studies retrieved brucellosis epidemiological data from administrative registries. Incidence data were often estimated on the basis of laboratory-confirmed tests. Not all studies included mortality estimates (Years of Life Lost) in their assessments due to lack of data or the assumption that brucellosis is not a fatal disease. Only two studies used a model with variable health states and corresponding disability weights. The rest used a simplified singular health state approach. Wide variation was seen in the duration chosen for brucellosis, ranging from 2 weeks to 4.5 years, irrespective of the whether a chronic state was included. Available brucellosis burden assessments vary widely in their methodology and assumptions. Further research is needed to better characterize the clinical course of brucellosis and to estimate case-fatality rates. Additionally, reporting of methodological choices should be improved to enhance transparency and comparability of estimates. These steps will increase the value of these estimates for policy makers. Brucellosis is a bacterial disease transmitted to humans by consumption of contaminated, unpasteurized milk or through direct contact with infected animals and their excretions. This disease causes production losses and has major economic impacts on in iduals and communities. The disability-adjusted life year (DALY) is a metric for measuring the burden. It summarizes mortality (years of life lost) and morbidity (years lived with disability) into a single metric. This review aimed to identify existing brucellosis burden studies and analyse their methodological choices, assumptions, and uncertainties. The results suggested that some parameters carry considerable uncertainty, particularly mortality and disease duration. This highlights the importance of strengthening routine reporting systems, collecting better mortality data and conducting further research on the course of brucellosis. Additionally, estimates of DALYs will benefit from a deeper understanding of the symptoms and the different sources of attribution. Finally, current reporting of methodological choices should be improved to enhance transparency, comparability, and consistency of brucellosis burden.
Publisher: Elsevier BV
Date: 12-2018
Publisher: Springer Science and Business Media LLC
Date: 12-2018
Publisher: Public Library of Science (PLoS)
Date: 13-05-2020
Publisher: Elsevier BV
Date: 09-2013
DOI: 10.1016/J.IJPARA.2013.05.011
Abstract: The diagnostic values of seven serological tests (ELISAs) and of the obligatory European Union-approved routine visual meat inspection for the detection of Taenia saginata cysticercosis were investigated. A total of 793 slaughtered dairy cows were selected in three European Union approved abattoirs in Switzerland, an endemic area (apparent prevalence by enhanced meat inspection up to 4.5%) with typically low parasite burdens. ELISAs based on a somatic larval antigen, isoelectric focused somatic larval antigen, larval excretory/secretory antigens, peptide HP6-2, peptide Ts45S-10, pooled peptide solution and a monoclonal antibody antigen capture assay were initially screened. As there is no perfect diagnostic 'gold standard' reference test, the obligatory meat inspection and four selected serological tests were further analysed using Bayesian inference to estimate the "true" prevalence and the diagnostic test sensitivities and specificities. The ELISA for specific antibody detection based on excretory/secretory antigens showed highest sensitivity and specificity with 81.6% (95% credible interval: 70-92) and 96.3% (95% credible interval: 94-99), respectively. The Bayesian model estimated the specificity of the ELISA, based on the synthetic peptide Ts45S-10 as 55.2% (95% credible interval: 46-65) and sensitivity as 84.7% (95% credible interval: 82-88). The sensitivity of the ELISA based on mAbs, detecting circulating antigen, was 14.3% (95% credible interval: 9-23) with a specificity of 93.7% (95% credible interval: 92-96). The diagnostic sensitivity of the obligatory standard European Union meat inspection procedure for the detection of T. saginata cysticercus infection at the abattoir was estimated to be 15.6% (95% credible interval: 10-23). Based on these data, the modelled prevalence of cysticercosis in dairy cows presented at abattoirs in Switzerland was estimated to be 16.5% (95% credible interval: 13-21). These cattle also had a high prevalence of infection with Dicrocoelium dendriticum (60.8%) and Fasciola hepatica (13.5%).
Publisher: Elsevier BV
Date: 03-2021
Publisher: Springer Science and Business Media LLC
Date: 27-06-2019
Publisher: Elsevier BV
Date: 05-2021
Publisher: Public Library of Science (PLoS)
Date: 03-12-2015
Publisher: Public Library of Science (PLoS)
Date: 03-12-2015
Publisher: Public Library of Science (PLoS)
Date: 03-12-2015
Publisher: Public Library of Science (PLoS)
Date: 19-01-2016
Location: United Kingdom of Great Britain and Northern Ireland
Location: Saint Kitts and Nevis
No related grants have been discovered for Paul Torgerson.