ORCID Profile
0000-0002-4529-102X
Current Organisations
Duke University
,
University of Otago
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Publisher: Oxford University Press (OUP)
Date: 05-2023
DOI: 10.1093/OFID/OFAD020
Abstract: Nontyphoidal Salmonella are a leading cause of community-onset bacteremia and other serious infections in sub-Saharan African countries where large studies indicate that they are an uncommon cause of moderate-to-severe diarrhea. Approximately 535 000 nontyphoidal Salmonella invasive disease illnesses and 77 500 deaths were estimated to occur in 2017 422 000 (78.9%) illnesses and 66 500 (85.9%) deaths in countries in sub-Saharan Africa. Lineages of Salmonella enterica serovar Typhimurium sequence type (ST) 313 and lineages of Salmonella enterica serovar Enteritidis ST11 dominate as causes of invasive disease. A major reservoir for these specific strains outside of humans has not been identified to date. Human fecal shedding of such strains is common in areas where nontyphoidal Salmonella invasive disease incidence is high. The case-fatality ratio of nontyphoidal Salmonella invasive disease is approximately 15%. Early diagnosis and treatment are needed to avert fatal outcomes. Antimicrobial resistance, including multiple drug resistance, decreased fluoroquinolone susceptibility, and resistance to third-generation cephalosporins, is increasing in prevalence and is likely to further compromise patient outcomes. Naturally acquired immunity against invasive disease develops in children aged & years in endemic areas, likely mediated in part by the sequential acquisition of T-cell immunity, followed by antigen-specific immunoglobulin G antibodies. Vaccines in preclinical or clinical development include live-attenuated S. enterica serovar Typhimurium, nontyphoidal S. enterica core and O-polysaccharide glycoconjugates, multiple antigen-presenting system complexes, and generalized modules for membrane antigens vaccines. The latter are in phase I trials in Europe and Africa. Both vaccine use, and other effective, evidence-based nonvaccine interventions, are needed to prevent and control nontyphoidal Salmonella invasive disease.
Publisher: Public Library of Science (PLoS)
Date: 18-03-2018
Publisher: American Physical Society (APS)
Date: 06-03-2023
Publisher: Elsevier BV
Date: 09-2023
Publisher: Public Library of Science (PLoS)
Date: 05-07-2022
DOI: 10.1371/JOURNAL.PNTD.0010516
Abstract: Growing evidence suggests considerable variation in endemic typhoid fever incidence at some locations over time, yet few settings have multi-year incidence estimates to inform typhoid control measures. We sought to describe a decade of typhoid fever incidence in the Kilimanjaro Region of Tanzania. Cases of blood culture confirmed typhoid were identified among febrile patients at two sentinel hospitals during three study periods: 2007–08, 2011–14, and 2016–18. To account for under-ascertainment at sentinel facilities, we derived adjustment multipliers from healthcare utilization surveys done in the hospital catchment area. Incidence estimates and credible intervals (CrI) were derived using a Bayesian hierarchical incidence model that incorporated uncertainty of our observed typhoid fever prevalence, of healthcare seeking adjustment multipliers, and of blood culture diagnostic sensitivity. Among 3,556 total participants, 50 typhoid fever cases were identified. Of typhoid cases, 26 (52%) were male and the median (range) age was 22 ( –60) years 4 (8%) were aged years and 10 (20%) were aged 5 to 14 years. Annual typhoid fever incidence was estimated as 61.5 (95% CrI 14.9–181.9), 6.5 (95% CrI 1.4–20.4), and 4.0 (95% CrI 0.6–13.9) per 100,000 persons in 2007–08, 2011–14, and 2016–18, respectively. There were no deaths among typhoid cases. We estimated moderate typhoid incidence (≥10 per 100 000) in 2007–08 and low ( per 100 000) incidence during later surveillance periods, but with overlapping credible intervals across study periods. Although consistent with falling typhoid incidence, we interpret this as showing substantial variation over the study periods. Given potential variation, multi-year surveillance may be warranted in locations making decisions about typhoid conjugate vaccine introduction and other control measures.
Publisher: Cold Spring Harbor Laboratory
Date: 26-08-2021
DOI: 10.1101/2021.08.23.457407
Abstract: Livestock abortion is an important cause of productivity losses worldwide and many infectious causes of abortion are zoonotic pathogens that impact on human health. Little is known about the relative importance of infectious causes of livestock abortion in Africa, including in subsistence farming communities that are critically dependent on livestock for food, income, and wellbeing. We conducted a prospective cohort study of livestock abortion, supported by cross-sectional serosurveillance, to determine aetiologies of livestock abortions in livestock in Tanzania. This approach generated several important findings including detection of a Rift Valley fever virus outbreak in cattle high prevalence of C. burnetii infection in livestock and the first report of Neospora caninum , Toxoplasma gondii, and pestiviruses associated with livestock abortion in Tanzania. Our approach provides a model for abortion surveillance in resource-limited settings. Our findings add substantially to current knowledge in sub-Saharan Africa, providing important evidence from which to prioritise disease interventions.
Publisher: Cold Spring Harbor Laboratory
Date: 30-12-2022
DOI: 10.1101/2022.12.28.22283969
Abstract: The Global Typhoid Genomics Consortium was established to bring together the typhoid research community to aggregate and analyse Salmonella enterica serovar Typhi (Typhi) genomic data to inform public health action. This analysis, which marks twenty-one years since the publication of the first Typhi genome, represents the largest Typhi genome sequence collection to date (n=13,000), and provides a detailed overview of global genotype and antimicrobial resistance (AMR) distribution and temporal trends, generated using open analysis platforms (GenoTyphi and Pathogenwatch). Compared with previous global snapshots, the data highlight that genotype 4.3.1 (H58) has not spread beyond Asia and Eastern/Southern Africa in other regions, distinct genotypes dominate and have independently evolved AMR. Data gaps remain in many parts of the world, and we show potential of travel-associated data to provide informal “sentinel” surveillance for such locations. The data indicate ciprofloxacin non-susceptibility ( resistance determinant) is widespread across geographies and genotypes, with high-level resistance (≥3 determinants) reaching 20% prevalence in South Asia. Extensively drug-resistant (XDR) typhoid has become dominant in Pakistan (70% in 2020), but has not yet become established elsewhere. Ceftriaxone resistance has emerged in eight non-XDR genotypes, including a ciprofloxacin-resistant lineage (4.3.1.2.1) in India. Azithromycin resistance mutations were detected at low prevalence in South Asia, including in two common ciprofloxacin-resistant genotypes. The Consortium’s aim is to encourage continued data sharing and collaboration to monitor the emergence and global spread of AMR Typhi, and to inform decision-making around the introduction of typhoid conjugate vaccines (TCVs) and other prevention and control strategies.
Publisher: eLife Sciences Publications, Ltd
Date: 03-07-2023
Publisher: Wiley
Date: 14-05-2021
DOI: 10.1002/SIM.8999
Abstract: It is difficult to estimate sensitivity and specificity of diagnostic tests when there is no gold standard. Latent class models have been proposed as a potential solution as they provide estimates without the need for a gold standard. Using a motivating ex le of the evaluation of point of care tests for leptospirosis in Tanzania, we show how a realistic violation of assumptions underpinning the latent class model can lead directly to substantial bias in the estimates of the parameters of interest. In particular, we consider the robustness of estimates of sensitivity, specificity, and prevalence, to the presence of additional latent states when fitting a two‐state latent class model. The violation is minor in the sense that it cannot be routinely detected with goodness‐of‐fit procedures, but is major with regard to the resulting bias.
Publisher: Oxford University Press (OUP)
Date: 07-03-2019
DOI: 10.1093/CID/CIY1094
Abstract: Contemporary incidence estimates of typhoid fever are needed to guide policy decisions and control measures and to improve future epidemiological studies. We systematically reviewed 3 databases (Ovid Medline, PubMed, and Scopus) without restriction on age, country, language, or time for studies reporting the incidence of blood culture–confirmed typhoid fever. Outbreak, travel-associated, and passive government surveillance reports were excluded. We performed a meta-analysis using a random-effects model to calculate estimates of pooled incidence, stratifying by studies that reported the incidence of typhoid fever and those that estimated incidence by using multipliers. Thirty-three studies were included in the analysis. There were 26 study sites from 16 countries reporting typhoid cases from population-based incidence studies, and 17 sites in 9 countries used multipliers to account for underascertainment in sentinel surveillance data. We identified Africa and Asia as regions with studies showing high typhoid incidence while noting considerable variation of typhoid incidence in time and place, including in consecutive years at the same location. Overall, more recent studies reported lower typhoid incidence compared to years prior to 2000. We identified variation in the criteria for collecting a blood culture, and among multiplier studies we identified a lack of a standardization for the types of multipliers being used to estimate incidence. Typhoid fever incidence remains high at many sites. Additional and more accurate typhoid incidence studies are needed to support country decisions about typhoid conjugate vaccine adoption. Standardization of multiplier types applied in multiplier studies is recommended.
Publisher: American Psychological Association (APA)
Date: 10-2022
DOI: 10.1037/EMO0000984
Abstract: Threat-based awe, or threat-awe, has been conceptualized as a fear-centric, negative-valenced variant of awe, although awe is a positive emotion embodying wonder and amazement. This research, however, argues that threat-awe is a mixed emotion rather than a negatively valenced subaspect of awe. We tested this conceptualization using two methodologies: (a) the theoretical framework of cognitive appraisals and (b) measures of ambivalence (an emotion co-occurrence index of bivalence, the Evaluative Space Grid, and a four-item scale to measure mixed emotions). Five studies (N = 1,140) compared threat-awe's appraisal profile and valence perceptions to univalenced, positive (awe, pride, happiness) and negative (fear) emotions. Research suggests that appraisal profiles of mixed emotions are close to their component emotions but distinct on certain appraisal dimensions. The empirical measures of valence demonstrate that threat-awe is felt as awe and fear in concert. Further, in terms of appraisals, threat-awe's appraisal profile is distinct from awe and fear on the dimensions of vastness, pleasantness, and situational control. Together, the two approaches-cognitive appraisals and measures of valence-provide convergent evidence that threat-awe is a mixed emotion. In conceptually clarifying threat-awe, we contribute to the nascent literature on mixed emotions. (PsycInfo Database Record (c) 2022 APA, all rights reserved).
Publisher: BMJ
Date: 08-2021
DOI: 10.1136/BMJGH-2021-005659
Abstract: Invasive non-typhoidal Salmonella (iNTS) is one of the leading causes of bacteraemia in sub-Saharan Africa. We aimed to provide a better understanding of the genetic characteristics and transmission patterns associated with multi-drug resistant (MDR) iNTS serovars across the continent. A total of 166 iNTS isolates collected from a multi-centre surveillance in 10 African countries (2010–2014) and a fever study in Ghana (2007–2009) were genome sequenced to investigate the geographical distribution, antimicrobial genetic determinants and population structure of iNTS serotypes–genotypes. Phylogenetic analyses were conducted in the context of the existing genomic frameworks for various iNTS serovars. Population-based incidence of MDR-iNTS disease was estimated in each study site. Salmonella Typhimurium sequence-type (ST) 313 and Salmonella Enteritidis ST11 were predominant, and both exhibited high frequencies of MDR Salmonella Dublin ST10 was identified in West Africa only. Mutations in the gyrA gene (fluoroquinolone resistance) were identified in S . Enteritidis and S . Typhimurium in Ghana an ST313 isolate carrying bla CTX-M-15 was found in Kenya. International transmission of MDR ST313 (lineage II) and MDR ST11 (West African clade) was observed between Ghana and neighbouring West African countries. The incidence of MDR-iNTS disease exceeded 100/100 000 person-years-of-observation in children aged years in several West African countries. We identified the circulation of multiple MDR iNTS serovar STs in the s led sub-Saharan African countries. Investment in the development and deployment of iNTS vaccines coupled with intensified antimicrobial resistance surveillance are essential to limit the impact of these pathogens in Africa.
Publisher: Springer Science and Business Media LLC
Date: 02-07-2018
Publisher: Informa UK Limited
Date: 2014
DOI: 10.1080/07359683.2014.874854
Abstract: Weather and its fluctuations have been found to influence the consumption of negative hedonic goods. However, such findings are of limited use to health marketers who cannot control the weather, and hence, its effects. The current research utilizes data obtained at the zip-code level to study geographical variations in the effect of weather on tobacco consumption across the entire continental United States. The results allow health marketers to identify areas that will be most responsive to marketing efforts aimed at curtailing negative hedonic consumption and thus implement more effective, region-specific initiatives.
Publisher: Cold Spring Harbor Laboratory
Date: 13-06-2023
DOI: 10.1101/2023.06.13.23291315
Abstract: To inform vaccine development strategies, we aimed to systematically review evidence on the prevalence and distribution of non-typhoidal Salmonella enterica serogroups and serovars. We searched four databases from inception through 4 June 2021. We included articles that reported at least one non-typhoidal Salmonella enterica strain by serogroup or serovar isolated from a normally sterile site. Of serogrouped isolates, we pooled the prevalence of serogroup O:4, serogroup O:9, and other serogroups using random-effects meta-analyses. Of serotyped isolates, we pooled the prevalence of Salmonella Typhimurium (member of serogroup O:4), Salmonella Enteritidis (member of serogroup O:9), and other serovars. Of 82 studies yielding 24,258 serogrouped isolates, pooled prevalence (95% CI) was 44.7% (36.3%-48.3%) for serogroup O:4, 45.4% (36.9%-49.0%) for serogroup O:9, and 9.9% (6.1%-13.3%) for other serogroups. Pooled prevalence (95%CI) was 36.8% (29.9%-44.0%) for Salmonella Typhimurium, 37.8% (33.2%-42.4%) for Salmonella Enteritidis, and 18.4% (11.4%-22.9%) for other serovars. Of global serogrouped non-typhoidal Salmonella isolates from normally sterile sites, serogroup O:4 and O:9 together accounted for 90%. Of global serotyped isolates, serovars Typhimurium and Enteritidis together accounted for 75%. Vaccine development strategies covering serogroups O:4 and O:9, or serovars Typhimurium and Enteritidis, have the potential to prevent the majority of non-typhoidal Salmonella invasive disease. PROSPERO:CRD42022376658. Invasive infections in normally sterile sites caused by non-typhoidal Salmonella have a case fatality ratio of 15%. Vaccine products for human non-typhoidal Salmonella are in currently in development. For future vaccine strategies, we provide global non-typhoidal Salmonella serogroup and serovar coverage by region and by age groups. Serogroups O:4 and O:9 account for 90% of isolates of non-typhoidal Salmonella enterica from normally sterile sites. Serovars Typhimurium and Enteritidis, members of serogroup O:4 and O:9, respectively, cover 75% of isolates of non-typhoidal Salmonella enterica from normally sterile sites.
Publisher: Oxford University Press (OUP)
Date: 10-08-2020
DOI: 10.1093/CID/CIAA1153
Abstract: Salmonella Enteritidis and Salmonella Typhimurium are major causes of bloodstream infection and diarrheal disease in East Africa. Sources of human infection, including the role of the meat pathway, are poorly understood. We collected cattle, goat, and poultry meat pathway s les from December 2015 through August 2017 in Tanzania and isolated Salmonella using standard methods. Meat pathway isolates were compared with nontyphoidal serovars of Salmonella enterica (NTS) isolated from persons with bloodstream infections and diarrheal disease from 2007 through 2017 from Kenya by core genome multi-locus sequence typing (cgMLST). Isolates were characterized for antimicrobial resistance, virulence genes, and ersity. We isolated NTS from 164 meat pathway s les. Of 172 human NTS isolates, 90 (52.3%) from stool and 82 (47.7%) from blood, 53 (30.8%) were Salmonella Enteritidis sequence type (ST) 11 and 62 (36.0%) were Salmonella Typhimurium ST313. We identified cgMLST clusters within Salmonella Enteritidis ST11, Salmonella Heidelberg ST15, Salmonella Typhimurium ST19, and Salmonella II 42:r:- ST1208 that included both human and meat pathway isolates. Salmonella Typhimurium ST313 was isolated exclusively from human s les. Human and poultry isolates bore more antimicrobial resistance and virulence genes and were less erse than isolates from other sources. Our findings suggest that the meat pathway may be an important source of human infection with some clades of Salmonella Enteritidis ST11 in East Africa, but not of human infection by Salmonella Typhimurium ST313. Research is needed to systematically examine the contributions of other types of meat, animal products, produce, water, and the environment to nontyphoidal Salmonella disease in East Africa.
Publisher: SAGE Publications
Date: 21-02-2021
Abstract: Across two studies, this research examines the effects of positive versus negative framing of health messages on food consumption, in the relatively short and long run. Specifically, it studies the effects of multiple exposures to health messages over time (Study 1), using daily food consumption diary data. It replicates and extends those findings in a cross-sectional, single exposure setting to tease out the in idual effects of positive and negative framing with consumption intentions as the dependent variable (Study 2). With this combination of an externally and internally valid setup, our research provides robust evidence of the associations of message effectiveness and behavioral outcomes. Our findings suggest that negative messages are more effective than positive messages in the short term but importantly, in the long term as well, suggesting that transforming consumption in the long term can be a viable social marketing objective with the appropriate message tactics. JEL Classification: M31, M37
Publisher: Wiley
Date: 29-09-2022
DOI: 10.1111/RISA.13826
Abstract: East Africa is a hotspot for foodborne diseases, including infection by nontyphoidal Salmonella (NTS), a zoonotic pathogen that may originate from livestock. Urbanization and increased demand for animal protein drive intensification of livestock production and food processing, creating risks and opportunities for food safety. We built a probabilistic mathematical model, informed by prior beliefs and dedicated stakeholder interviews and microbiological research, to describe sources and prevalence of NTS along the beef supply chain in Moshi, Tanzania. The supply chain was conceptualized using a bow tie model, with terminal livestock markets as pinch point, and a forked pathway postmarket to compare traditional and emerging supply chains. NTS was detected in 36 (7.7%) of 467 s les throughout the supply chain. After combining prior belief and observational data, marginal estimates of true NTS prevalence were 4% in feces of cattle entering the beef supply and 20% in raw meat at butcheries. Based on our model and sensitivity analyses, true NTS prevalence was not significantly different between supply chains. Environmental contamination, associated with butchers and vendors, was estimated to be the most likely source of NTS in meat for human consumption. The model provides a framework for assessing the origin and propagation of NTS along meat supply chains. It can be used to inform decision making when economic factors cause changes in beef production and consumption, such as where to target interventions to reduce risks to consumers. Through sensitivity and value of information analyses, the model also helps to prioritize investment in additional research.
Publisher: BMJ
Date: 05-2022
DOI: 10.1136/BMJOPEN-2021-056696
Abstract: To examine the world’s population, development, and health by condensed Coordinated Universal Time (UTC) offset to support a normative position on how to most defensibly schedule global health teleconferences with the primary goal of advancing equitable regard for participants by health condition. Spatial exploration examined through the lens of equitable regard for participants. The Earth. The global population. Global population, countries, Human Development Index (HDI), and health measured in total and disease-specific disability-adjusted life years (DALYs) per 100 000 per year by UTC offset. Strengths and weaknesses of scheduling teleconferences accordingly to alternative approaches. The UTC offset with the largest population of approximately 1 724 million persons occurred in UTC+5, largest country count of approximately 40 countries in UTC+1, and the lowest median HDI of 0.527 occurred in UTC0. The highest median total DALYs per 100 000 per year of 41 873 occurred in UTC+11, highest median HIV/AIDS DALYs per 100 000 per year of 941 in UTC0, and highest median typhoid and paratyphoid fevers DALYs per 100 000 per year of 279 occurred in UTC+5. Hypothetical teleconference scheduling scenarios generated temporal distances of up to 11 hours to UTC offsets representing the most countries and greatest number of DALYs per 100 000 per year. Teleconference scheduling based on egoism was considered to be problematic, and contractualism as unrealistically demanding. Utilitarianism resulted in the risk of systematically disadvantaging small, temporally remote groups. Egalitarianism offered equality, but prioritarianism offered the possibility of addressing health inequities. Global health teleconferences may generate great temporal distances between participants compromising representative participation, as well as the well-being of attendees. Our spatial exploration of the world’s population and health by UTC offset may be used to support a normative position on scheduling global health teleconferences that enhance progress towards health equity.
Publisher: Public Library of Science (PLoS)
Date: 30-04-2020
Publisher: Springer Science and Business Media LLC
Date: 28-04-2017
Publisher: Cold Spring Harbor Laboratory
Date: 12-12-2020
DOI: 10.1101/2020.12.11.422246
Abstract: Invasive nontyphoidal Salmonella (iNTS) is one of the leading causes of bacteraemia in sub-Saharan Africa. Multi-drug resistance (MDR) and further resistance to third generation cephalosporins and fluoroquinolones have emerged in multiple iNTS serotypes. Molecular epidemiological investigations of nontyphoidal Salmonella are needed to better understand the genetic characteristics and transmission dynamics associated with major MDR iNTS serotypes across the continent. A total of 166 nontyphoidal Salmonella isolates causing invasive disease were collected from a multi-centre study in eight African countries between 2010 and 2014, and whole-genome sequenced to investigate the geographical distribution, antimicrobial genetic determinants and population structure of iNTS serotypes-genotypes. Phylogeographical reconstruction was further conducted in context of the existing genomic framework of iNTS serotypes Typhimurium and Enteritidis. Population-based incidence of MDR-iNTS disease was also estimated. Salmonella enterica subsp. Enterica serotype Typhimurium ( S . Typhimurium) sequence-type (ST) 313 and Salmonella enterica subsp. Enterica serotype Enteritidis ( S . Enteritidis) ST11 were predominant, and both exhibited high frequencies of MDR. Salmonella enterica subsp. Enterica serotype Dublin ( S . Dublin) ST10 emerged in West Africa. Mutations in the gyrA gene were identified in S . Enteritidis and S . Typhimurium in Ghana and ST313 carrying bla CTX-M-15 was found in Kenya. Inter-country transmission of MDR ST313 lineage II and the West African Clade of MDR ST11 between Ghana and neighbouring countries including Mali, Burkina Faso, and Nigeria were evident. The incidence of MDR-iNTS disease exceeded 100/100,000-person years-of-observation (PYO) in children aged years in several West African countries. Multiple MDR iNTS serotypes-sequence types, predominantly S . Typhimurium ST313 and S . Enteritidis ST11, are co-circulating in sub-Saharan Africa with evidence of transmission between West African countries. The development of safe and effective iNTS vaccines coupled with appropriate antimicrobial stewardship and adequate epidemiological monitoring are essential to limit the impact of these pathogens in Africa.
Publisher: Elsevier BV
Date: 06-2015
Publisher: Elsevier BV
Date: 09-2022
DOI: 10.1016/J.IJID.2022.07.018
Abstract: In this study, we aimed to conduct a systematic review to characterize antimicrobial resistance (AMR) patterns for bacterial causes of febrile illness in Africa and Asia. We included published literature from 1980-2015 based on data extracted from two recent systematic reviews of nonmalarial febrile illness from Africa, South Asia, and Southeast Asia. Selection criteria included articles with full bacterial identification and antimicrobial susceptibility testing (AST) results for key normally sterile site pathogen-drug combinations. Pooled proportions of resistant isolates were combined using random effects meta-analysis. Study data quality was graded using the Microbiology Investigation Criteria for Reporting Objectively (MICRO) framework. Of 3475 unique articles included in the previous reviews, 371 included the target pathogen-drug combinations. Salmonella enterica tested against ceftriaxone and ciprofloxacin were the two highest reported combinations (30,509 and 22,056 isolates, respectively). Pooled proportions of resistant isolates were high for third-generation cephalosporins for Klebsiella pneumoniae and Escherichia coli in all regions. The MICRO grading showed an overall lack of standardization. This review highlights a general increase in AMR reporting and in resistance over time. However, there were substantial problems with diagnostic microbiological data quality. Urgent strengthening of laboratory capacity, standardized testing, and reporting of AST results is required to improve AMR surveillance.
Publisher: eLife Sciences Publications, Ltd
Date: 12-09-2023
DOI: 10.7554/ELIFE.85867
Publisher: Elsevier BV
Date: 07-2022
Publisher: BMJ
Date: 08-2023
DOI: 10.1136/BMJGH-2023-012369
Abstract: Liberia was heavily affected by the 2014–2016 Ebola virus disease (EVD) outbreak. With substantial investments in interventions to combat future outbreaks, it is hoped that Liberia is well prepared for a new incursion. We assessed the performance of the current EVD surveillance system in Liberia, focusing on its ability to promptly detect a new EVD outbreak. We integrated WHO and US Centers for Disease Control and Prevention guidelines for public health surveillance system evaluation and used standardised indicators to measure system performance. We conducted 23 key informant interviews, 150 health facility assessment surveys and a standardised patient (SP) study (19 visits) from January 2020 to January 2021. Data were summarised and a gap analysis conducted. We found basic competencies of case detection and reporting necessary for a functional surveillance system were in place. At the higher (national, county and district) levels, we found performance gaps in 2 of 6 indicators relating to surveillance system structure, 3 of 14 indicators related to core functions, 1 of 5 quality indicators and 2 of 8 indicators related to support functions. The health facility assessment found performance gaps in 9 of 10 indicators related to core functions, 5 of 6 indicators related to support functions and 3 of 7 indicators related to quality. The SP simulations revealed large gaps between expected and actual practice in managing a patient warranting investigation for EVD. Major challenges affecting the system’s operations across all levels included limited access to resources to support surveillance activities, persistent stock out of s le collection materials and attrition of trained staff. The EVD surveillance system in Liberia may fail to promptly detect a new EVD outbreak. Specific improvements are required, and regular evaluations recommended. SP studies could be crucial in evaluating surveillance systems for rarely occurring diseases that are important to detect early.
Publisher: Elsevier BV
Date: 09-2016
Publisher: Cold Spring Harbor Laboratory
Date: 03-10-2023
Publisher: Informa UK Limited
Date: 12-2017
Publisher: Public Library of Science (PLoS)
Date: 24-08-2021
DOI: 10.1371/JOURNAL.PNTD.0009630
Abstract: Brucellosis is a neglected zoonosis endemic in many countries, including regions of sub-Saharan Africa. Evaluated diagnostic tools for the detection of exposure to Brucella spp. are important for disease surveillance and guiding prevention and control activities. Bayesian latent class analysis was used to evaluate performance of the Rose Bengal plate test (RBT) and a competitive ELISA (cELISA) in detecting Brucella spp. exposure at the in idual animal-level for cattle, sheep, and goats in Tanzania. Median posterior estimates of RBT sensitivity were: 0.779 (95% Bayesian credibility interval (BCI): 0.570–0.894), 0.893 (0.636–0.989), and 0.807 (0.575–0.966), and for cELISA were: 0.623 (0.443–0.790), 0.409 (0.241–0.644), and 0.561 (0.376–0.713), for cattle, sheep, and goats, respectively. Sensitivity BCIs were wide, with the widest for cELISA in sheep. RBT and cELISA median posterior estimates of specificity were high across species models: RBT ranged between 0.989 (0.980–0.998) and 0.995 (0.985–0.999), and cELISA between 0.984 (0.974–0.995) and 0.996 (0.988–1). Each species model generated seroprevalence estimates for two livestock subpopulations, pastoralist and non-pastoralist. Pastoralist seroprevalence estimates were: 0.063 (0.045–0.090), 0.033 (0.018–0.049), and 0.051 (0.034–0.076), for cattle, sheep, and goats, respectively. Non-pastoralist seroprevalence estimates were below 0.01 for all species models. Series and parallel diagnostic approaches were evaluated. Parallel outperformed a series approach. Median posterior estimates for parallel testing were ≥0.920 (0.760–0.986) for sensitivity and ≥0.973 (0.955–0.992) for specificity, for all species models. Our findings indicate that Brucella spp. surveillance in Tanzania using RBT and cELISA in parallel at the animal-level would give high test performance. There is a need to evaluate strategies for implementing parallel testing at the herd- and flock-level. Our findings can assist in generating robust Brucella spp. exposure estimates for livestock in Tanzania and wider sub-Saharan Africa. The adoption of locally evaluated robust diagnostic tests in setting-specific surveillance is an important step towards brucellosis prevention and control.
Publisher: Public Library of Science (PLoS)
Date: 09-06-2022
DOI: 10.1371/JOURNAL.PONE.0269725
Abstract: Timely health care seeking with access to quality health care are crucial to improve child survival. We conducted a study which aimed to identify factors influencing timely health care seeking and choice of first source of health care in Ethiopia. A total of 535 caregivers who sought health care for febrile children aged under 5 years at a tertiary hospital, and one urban and two rural health centres in Hawassa, southern Ethiopia were recruited to participate in the study from August to November 2019. Caregivers were interviewed using pretested structured questionnaires on socio-demographic and clinical factors to identify associations with health care seeking practice and first source of care, and reasons for particular practices. Delayed care seeking was defined as seeking care from a health facility after 24 hours of onset of fever. Of 535 caregivers who participated, 271 (50.7%) had sought timely health care 400 (74.8%) utilized a primary health care (PHC) facility as first source and 282 (52.7%) bypassed the nearest PHC facility. Rural residents (adjusted odds ratio (AOR) 1.85 95% CI 1.11–3.09), and those who reported cough (AOR 1.87 95% CI 1.20–2.93) as a reason for consultation were more likely to delay seeking health care. While caregivers were less likely delayed for children aged 24–35 months (AOR 0.50 95% CI 0.28–0.87) compared to infants. Utilizing higher-level hospitals as the first source of care was less frequent among rural residents (AOR 0.15 95% CI 0.06–0.39) and in those with no formal education (AOR 0.03 95% CI 0.01–0.27). Those having a longer travel time to the provider (AOR 2.11 95% CI 1.09–4.08) more likely utilized higher hospitals. We identified a need to improve timely health seeking among rural residents, infants, and those presenting with respiratory symptoms. Improvements may be achieved by educating communities on the need of early care seeking, and ensuring the communities members’ expectations of services at each level consistent with the services capacity.
Publisher: Cambridge University Press (CUP)
Date: 18-10-2023
Publisher: Springer Science and Business Media LLC
Date: 11-05-2015
DOI: 10.1038/NG.3281
Publisher: No publisher found
Date: 2023
Publisher: Elsevier BV
Date: 03-2022
Publisher: Oxford University Press (OUP)
Date: 08-2023
DOI: 10.1093/OFID/OFAD448
Abstract: We describe antibacterial use in light of microbiology data and treatment guidelines for common febrile syndromes in Moshi, Tanzania. We compared data from 2 hospital-based prospective cohort studies, cohort 1 (2011–2014) and cohort 2 (2016–2019), that enrolled febrile children and adults. A study team member administered a standardized questionnaire, performed a physical examination, and collected blood cultures. Participants with bloodstream infection (BSI) were categorized as receiving effective or ineffective therapy based upon antimicrobial susceptibility interpretations. Antibacterials prescribed for treatment of pneumonia, urinary tract infection (UTI), or presumed sepsis were compared with World Health Organization and Tanzania Standard Treatment Guidelines. We used descriptive statistics and logistic regression to describe antibacterial use. Among participants, 430 of 1043 (41.2%) and 501 of 1132 (44.3%) reported antibacterial use prior to admission in cohorts 1 and 2, respectively. During admission, 930 of 1043 (89.2%) received antibacterials in cohort 1 and 1060 of 1132 (93.6%) in cohort 2. Inpatient use of ceftriaxone, metronidazole, and icillin increased between cohorts (P ≤ .002 for each). BSI was detected in 38 (3.6%) participants in cohort 1 and 47 (4.2%) in cohort 2. Of 85 participants with BSI, 81 (95.3%) had complete data and 52 (64.2%) were prescribed effective antibacterials. Guideline-consistent therapy in cohort 1 and cohort 2 was as follows: pneumonia, 87.4% and 56.8% UTI, 87.6% and 69.0% sepsis, 84.4% and 61.2% (P ≤ .001 for each). Receipt of antibacterials for febrile illness was common. While guideline-consistent prescribing increased over time, more than one-third of participants with BSI received ineffective antibacterials.
Publisher: Wiley
Date: 13-09-2021
DOI: 10.1002/SIM.9157
Publisher: American Psychological Association (APA)
Date: 07-2023
DOI: 10.1037/XGE0001372
Publisher: Wiley
Date: 12-04-2023
DOI: 10.1002/JCPY.1349
Abstract: Given its multi‐faceted nature, consumer research has evinced interest from scholars both within and outside the marketing domain, resulting in ongoing knowledge contributions from a erse range of disciplines. We conduct a comprehensive review and comparison across both marketing (“inside”) and non‐marketing (“outside”) disciplines to identify which topics are most and least focused on within each disciplinary domain and which are emerging as the most impactful. We also identify which of the marketing (FT50) journals are at the forefront of cutting‐edge research and demonstrate their contributions to the progression of the most impactful topics in the field. Based on our findings, we identify key gaps and under‐researched areas of substantive interest, highlight impactful emerging topics in non‐marketing journals where marketing could offer unique perspectives, and provide concrete suggestions and directions to further progress and stimulate consumer research.
Publisher: Public Library of Science (PLoS)
Date: 27-06-2018
Publisher: Public Library of Science (PLoS)
Date: 12-02-2019
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 03-08-2021
Abstract: Rigorous incidence data for acute myocardial infarction (AMI) in sub‐Saharan Africa are lacking. Consequently, modeling studies based on limited data have suggested that the burden of AMI and AMI‐associated mortality in sub‐Saharan Africa is lower than in other world regions. We estimated the incidence of AMI in northern Tanzania in 2019 by integrating data from a prospective surveillance study (681 participants) and a community survey of healthcare‐seeking behavior (718 participants). In the surveillance study, adults presenting to an emergency department with chest pain or shortness of breath were screened for AMI with ECG and troponin testing. AMI was defined by the Fourth Universal Definition of AMI criteria. Mortality was assessed 30 days following enrollment via in‐person or telephone interviews. In the cluster‐based community survey, adults in northern Tanzania were asked where they would present for chest pain or shortness of breath. Multipliers were applied to account for AMI cases that would have been missed by our surveillance methods. The estimated annual incidence of AMI was 172 (207 among men and 139 among women) cases per 100 000 people. The age‐standardized annual incidence was 211 (263 among men and 170 among women) per 100 000 people. The estimated annual incidence of AMI‐associated mortality was 87 deaths per 100 000 people, and the age‐standardized annual incidence was 102 deaths per 100 000 people. The incidence of AMI and AMI‐associated mortality in northern Tanzania is much higher than previously estimated and similar to that observed in high‐income countries.
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for John A. Crump.