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1.
Risk Anal ; 2024 May 22.
Article in English | MEDLINE | ID: mdl-38777618

ABSTRACT

Qualitative frameworks are widely employed to tackle urgent animal or public health issues when data are scarce and/or urgent decisions need to be made. In qualitative models, the degree of belief regarding the probabilities of the events occurring along the risk pathway(s) and the outcomes is described in nonnumerical terms, typically using words such as Low, Medium, or High. The main methodological challenge, intrinsic in qualitative models, relates to performing mathematical operations and adherence to the rule of probabilities when probabilities are nonnumerical. Although methods to obtain the qualitative probability from the conditional realization of n events are well-established and consistent with the multiplication rule of probabilities, there is a lack of accepted methods for addressing situations where the probability of an event occurring can increase, and the rule of probability P(AUB) = P(A) + P(B) - P(A∩B) should apply. In this work, we propose a method based on the pairwise summation to fill this methodological gap. Our method was tested on two qualitative models and compared by means of scenario analysis to other approaches found in literature. The qualitative nature of the models prevented formal validation; however, when using the pairwise summation, results consistently appeared more coherent with probability rules. Even if the final qualitative estimate can only represent an approximation of the actual probability of the event occurring, qualitative models have proven to be effective in providing scientific-based evidence to support decision-making. The method proposed in this study contributes to reducing the subjectivity that characterizes qualitative models, improving transparency and reproducibility.

2.
Am J Trop Med Hyg ; 2024 May 14.
Article in English | MEDLINE | ID: mdl-38744272

ABSTRACT

Nontyphoidal Salmonella is one of the major causes of self-limiting diarrheal disease and the most common foodborne pathogen worldwide. It is an important contributor to the burden of foodborne illness in South America, including Peru, where chicken and pork are important vehicles for Salmonella infection. Salmonella infections are underreported, particularly in low- and middle-income countries where concerted action tackling Salmonella along the chicken and pork chains, from primary production to retail, is urgently needed. To support and inform the implementation of new strategies to reduce Salmonella contamination of chicken and pork, this study describes the frequency and distribution of foodborne outbreaks attributed to Salmonella in Peru and evaluates the level of Salmonella in chicken and pork meat sold in markets of three regions of Peru. To that end, we analyzed historical reports of foodborne outbreaks, levels of Salmonella in chicken and pork sold in markets, and the number of mesophiles in the collected meat samples. As a result, the microbiological analysis reveals a widespread contamination of chicken (77.1%) and pork (26.8%) with Salmonella. It also pinpoints Salmonella as the causative agent in nearly half of the outbreaks (47.0%) where the potential origin is identified over a 11-year period with chicken, mayonnaise, and pork being the most likely food vehicles. These results suggest that Salmonella is a major contributor to foodborne illness in Peru and that the monitoring of mesophiles could be a good strategy for surveillance, generating data to support source attribution studies and ultimately evidence-informed policies.

3.
IJID Reg ; 9: 95-101, 2023 Dec.
Article in English | MEDLINE | ID: mdl-38020182

ABSTRACT

Objectives: This study aimed to ascertain which factors are associated with higher risk of mortality among hospitalized COVID-19 Bolivian patients. Methods: This retrospective observational study assessed risk factors associated with mortality in patients (n = 549) hospitalized for SARS-CoV-2 infection in a Bolivian hospital between April 6, 2020, and August 18, 2022. Results: The results provide evidence of association between male sex (odds ratio [OR] = 1.6, 95% confidence interval [CI] 1.06-2.6), older age, 51-61 years-old (OR = 5.2, 95% CI 2.2-12.6), 62-70 years-old (OR = 8.7, 95% CI 3.7-20.5), >70 years-old (OR = 16.9, 95% CI 7.1-39.9), and blood group A (OR = 1.9, 95% CI: 1.1-3.4) with higher mortality risk. The strong association between mortality and relatively young age, may be due to high frequency of undiagnosed comorbidities. Vaccination was associated with a reduction in mortality only when time period of hospitalization was not adjusted for. Conclusion: Among hospitalized patients in Bolivia male sex, older age, and blood group A are associated with higher mortality risk. Mortality risk increased markedly from a relatively young age and decreased in parallel to the uptake of the vaccination program. However, the gradual reduction in mortality can also be due to improved patient management and changes in natural immunity and virulence of circulating strains as the pandemic progressed.

4.
BMC Vet Res ; 19(1): 228, 2023 Nov 02.
Article in English | MEDLINE | ID: mdl-37919680

ABSTRACT

BACKGROUND: Middle East respiratory syndrome coronavirus (MERS-CoV) was identified in humans in 2012. Since then, 2605 cases and 937 associated deaths have been reported globally. Camels are the natural host for MERS-CoV and camel to human transmission has been documented. The relationship between MERS-CoV shedding and presence of neutralizing antibodies in camels is critical to inform surveillance and control, including future deployment of camel vaccines. However, it remains poorly understood. The longitudinal study conducted in a closed camel herd in Egypt between December 2019 and March 2020 helped to characterize the kinetics of MERS-CoV neutralizing antibodies and its relation with viral shedding. RESULTS: During the 100-day longitudinal study, 27 out of 54 camels (50%) consistently tested negative for presence of antibodies against MERS-CoV, 19 (35.2%) tested positive and 8 (14.8%) had both, positive and negative test results. Fourteen events that could be interpreted as serological indication of probable infection (two seroconversions and twelve instances of positive camels more than doubling their optical density ratio (OD ratio) in consecutive samples) were identified. Observed times between the identified events provided strong evidence (p = 0.002) against the null hypothesis that they occurred with constant rate during the study, as opposed to clustering at certain points in time. A generalized additive model showed that optical density ratio (OD ratio) is positively associated with being an adult and varies across individual camels and days, peaking at around days 20 and 90 of the study. Despite serological indication of probable virus circulation and intense repeated sampling, none of the tested nasal swab samples were positive for MERS-CoV RNA, suggesting that, if the identified serological responses are the result of virus circulation, the virus may be present in nasal tissue of infected camels during a very narrow time window. CONCLUSIONS: Longitudinal testing of a closed camel herd with past history of MERS-CoV infection is compatible with the virus continuing to circulate in the herd despite lack of contact with other camels. It is likely that episodes of MERS-CoV infection in camels can take place with minimal presence of the virus in their nasal tissues, which has important implications for future surveillance and control of MERS-CoV in camel herds and prevention of its zoonotic transmission.


Subject(s)
Coronavirus Infections , Middle East Respiratory Syndrome Coronavirus , Animals , Humans , Middle East Respiratory Syndrome Coronavirus/genetics , Camelus , Longitudinal Studies , Coronavirus Infections/epidemiology , Coronavirus Infections/veterinary , Antibodies, Neutralizing
5.
Prev Vet Med ; 219: 106022, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37738751

ABSTRACT

Johne's disease (JD) is a chronic disease of ruminants endemic in the UK and other countries and responsible for large economic losses for the dairy sector. JD is caused by Mycobacterium avium subspecies paratuberculosis (MAP), which typically infects calves that remain latently infected during a long period, making early detection of infection challenging. Cow to calf transmission can occur in-utero, via milk/colostrum or faecal-orally. Understanding of the different transmission routes to calves is important in informing control recommendations. Our aim in this longitudinal study was to measure the association between the transmission routes via the dam and the environment on a calf subsequently testing serologically positive for MAP. The study population comprised of 439 UK dairy calves from 6 herds enrolled between 2012 and 2013. These calves were followed up from birth until 2023. At birth individual calf data was captured. During follow-up, individuals entering the milking herd were quarterly tested for the presence of MAP antibodies using milk ELISA. Cox regression models were used to measure the association between exposure from the dam (in-utero and/or colostrum) or from the environment (long time in dirty yard) and time to first detection of MAP infection. An association between calves born to positive dams and probability of having a MAP positive test result remained after excluding potential MAP transmission via colostrum (Hazard ratio: 2.24; 95% CI: 1.14 - 4.41). Calves unlikely to be infected with MAP via the in-utero or colostrum route, had 3.68 (95% CI: 3.68 1.45-9.33) higher hazard of a positive test result when they stayed longer in a dirty calving area. The effect of the dam infection status on transmission to calves precedes the dam's seroconversion and persists after excluding the potential role of transmission via colostrum. The association between time spent in a dirty calving area and probability of a MAP positive test result highlights the role of environmental contamination as a source of infection in addition to the dam.


Subject(s)
Cattle Diseases , Mycobacterium avium subsp. paratuberculosis , Paratuberculosis , Humans , Female , Animals , Cattle , Longitudinal Studies , Cattle Diseases/prevention & control , Paratuberculosis/microbiology , Milk/microbiology , Enzyme-Linked Immunosorbent Assay/veterinary
6.
Philos Trans R Soc Lond B Biol Sci ; 378(1887): 20220407, 2023 10 09.
Article in English | MEDLINE | ID: mdl-37598706

ABSTRACT

Zoonotic diseases (zoonoses) originating from domestic animals pose a significant risk to people's health and livelihoods, in addition to jeopardizing animal health and production. Effective surveillance of endemic zoonoses at the animal level is crucial to assessing the disease burden and risk, and providing early warning to prevent epidemics in animals and spillover to humans. Here we aimed to prioritize and characterize zoonoses for which surveillance in domestic animals is important to prevent human infections at a global scale. A multi-criteria qualitative approach was used, where disease-specific information was obtained across literature of the leading international health organizations. Thirty-two zoonoses were prioritized, all of which have multi-regional spread, cause unexceptional human infections and have domestic animal hosts as important sources or sentinels of zoonotic infections. Most diseases involve multiple animal hosts and/or modes of zoonotic transmission, where a lack of specific clinical signs in animals further complicates surveillance. We discuss the challenges of animal health surveillance in endemic and resource-limited settings, as well as potential avenues for improvement such as the multi-disease, multi-sectoral and digital surveillance approaches. Our study will support global capacity-building efforts to strengthen the surveillance and control of endemic zoonoses at their animal sources. This article is part of the theme issue 'Challenges and opportunities in the fight against neglected tropical diseases: a decade from the London Declaration on NTDs'.


Subject(s)
Epidemics , Public Health , Animals , Humans , Animals, Domestic , Zoonoses/epidemiology , Zoonoses/prevention & control , Cost of Illness , Neglected Diseases
7.
Am J Trop Med Hyg ; 109(3): 568-570, 2023 09 06.
Article in English | MEDLINE | ID: mdl-37487566

ABSTRACT

Shiga toxin-producing Escherichia coli (STEC) O157:H7 is a food and waterborne pathogen with severe public health implications. We report the first-time isolation of this pathogen in the Central Highlands of Peru through standardized culture procedures and polymerase chain reaction (PCR). Escherichia coli strains were cultured from rectal-anal swabs from dairy calves and beef from food markets. The latex agglutination test was used to detect O157 and H7 antigens, and multiplex real-time PCR was carried out to detect virulence-related genes. The STEC O157:H7 strains were isolated from 3.5% (1/28) of beef samples and from 6.0% (3/50) of dairy calves that also carried both eaeA and stx1 genes. Therefore, this pathogen is a potential cause of food/waterborne disease in the region, and its surveillance in both livestock and their products should be improved to characterize the impact of its zoonotic transmission. From 2010 to 2020, E. coli was suspected in 10 outbreaks reported to the Peruvian Ministry of Health. Isolates from future outbreaks should be characterized to assess the burden posed by STEC O157:H7 in Peru.


Subject(s)
Escherichia coli O157 , Food Microbiology , Red Meat , Escherichia coli O157/genetics , Escherichia coli O157/isolation & purification , Escherichia coli O157/pathogenicity , Red Meat/microbiology , Feces/microbiology , Animals , Cattle , Dairying , Peru , Polymerase Chain Reaction , Latex Fixation Tests , Virulence Factors/genetics
8.
Front Vet Sci ; 10: 1143375, 2023.
Article in English | MEDLINE | ID: mdl-37089403

ABSTRACT

A workforce with the adequate field epidemiology knowledge, skills and abilities is the foundation of a strong and effective animal health system. Field epidemiology training is conducted in several countries to meet the increased global demand for such a workforce. However, core competencies for field veterinary epidemiology have not been identified and agreed upon globally, leading to the development of different training curricula. Having a set of agreed core competencies can harmonize field veterinary epidemiology training. The Food and Agriculture Organization of the United Nations (FAO) initiated a collective, iterative, and participative process to achieve this and organized two expert consultative workshops in 2018 to develop core competencies for field veterinary epidemiology at the frontline and intermediate levels. Based on these expert discussions, 13 competencies were identified for the frontline and intermediate levels. These competencies were organized into three domains: epidemiological surveillance and studies; field investigation, preparedness and response; and One Health, communication, ethics and professionalism. These competencies can be used to facilitate the development of field epidemiology training curricula for veterinarians, adapted to country training needs, or customized for training other close disciplines. The competencies can also be useful for mentors and employers to monitor and evaluate the progress of their mentees, or to guide the selection process during the recruitment of new staff.

9.
IJID Reg ; 6: 159-166, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36721772

ABSTRACT

Objectives: The global reported cumulative case-fatality ratios (rCFRs) and excess mortality rates of the 20 countries with the highest coronavirus disease 2019 (COVID-19) vaccination rates, the rest of the world and Sub-Saharan Africa (SSA) were compared before and after the commencement of vaccination programmes. Methods: A time series model was used to understand the trend of rCFR over time, and a generalized linear mixed model was used to understand the effect of vaccination on rCFR. Results: By 31 December 2022, an average of 260.3 doses of COVID-19 vaccine per 100 population had been administered in the top 20 vaccinated countries, compared with 152.1 doses in the rest of the world and 51.2 doses in SSA. The mean rCFR of COVID-19 had decreased by 69.0% in the top 20 vaccinated countries, 26.5% in the rest of the world and 7.6% in SSA. Excess mortality had decreased by 48.7% in the top 20 vaccinated countries, compared with 62.5% in the rest of the world and 60.7% in SSA. In a generalized linear mixed model, the reported number of vaccine doses administered (/100 population) (odds ratio 0.64) was associated with a steeper reduction in COVID-19 rCFR. Conclusions: Vaccine equity and faster roll-out across the world is critically important in reducing COVID-19 transmission and CFR.

10.
Zoonoses Public Health ; 70(3): 238-247, 2023 05.
Article in English | MEDLINE | ID: mdl-36601879

ABSTRACT

Q fever represents an important 'neglected zoonosis', with high prevalences recorded across the Middle East region. Among rural desert-dwelling communities in the region, camel milk is largely consumed raw, due to perceptions of dromedaries as a uniquely clean livestock species mentioned in the Qur'an and Islamic hadith, while milk from other livestock species is usually boiled. As a result, camels present a unique public health threat among such communities from milk-borne pathogens, including Coxiella burnetii. In view of this, a cross-sectional study was conducted among dromedary herds in southern Jordan between September 2017 and October 2018, including 404 camels from 121 randomly selected herds. In addition, 510 household members associated with these herds were interviewed regarding potential high-risk practices for zoonotic transmission. Weight adjusted camel population seroprevalence for C. burnetii was 49.6% (95% CI: 44.7-54.5), with evidence of maternally derived immunity in calves ≤6 months old. Adjusted herd-level prevalence was 76.0% (95% CI 72.7-80.2). It was estimated 30.4% (144/477) of individuals consumed raw milk from infected herds monthly or more. Following multivariable logistic regression analysis, seropositive status in camels was found to be associated with increasing age, high herd tick burdens, keeping the herd together throughout the year including when calving, and owning larger (>50) sheep and goat flocks, with goats presenting a higher risk than sheep. Racing camel status was found to be protective. Socioculturally appropriate interventions aimed at raising awareness of potential risks associated with drinking raw camel milk, alongside appropriate livestock management interventions, should be considered.


Subject(s)
Coxiella burnetii , Goat Diseases , Q Fever , Animals , Sheep , Q Fever/epidemiology , Q Fever/veterinary , Camelus , Cross-Sectional Studies , Public Health , Seroepidemiologic Studies , Ruminants , Goats , Risk Factors , Goat Diseases/epidemiology
11.
Proc Biol Sci ; 289(1976): 20220400, 2022 06 08.
Article in English | MEDLINE | ID: mdl-35703046

ABSTRACT

Food poisoning caused by Campylobacter (campylobacteriosis) is the most prevalent bacterial disease associated with the consumption of poultry, beef, lamb and pork meat and unpasteurized dairy products. A variety of livestock industry, food chain and public health interventions have been implemented or proposed to reduce disease prevalence, some of which entail costs for producers and retailers. This paper describes a project that set out to summarize the natural science evidence base relevant to campylobacteriosis control in as policy-neutral terms as possible. A series of evidence statements are listed and categorized according to the nature of the underlying information. The evidence summary forms the appendix to this paper and an annotated bibliography is provided in the electronic supplementary material.


Subject(s)
Campylobacter Infections , Campylobacter , Natural Science Disciplines , Animals , Campylobacter Infections/epidemiology , Campylobacter Infections/microbiology , Campylobacter Infections/veterinary , Cattle , Humans , Meat/microbiology , Prevalence , Sheep
12.
J Vet Med Educ ; : e20220013, 2022 Jun 22.
Article in English | MEDLINE | ID: mdl-35737887

ABSTRACT

Previously, pig production was not covered in the Jordan University of Science and Technology's (JUST) veterinary curriculum due to Jordan being a predominantly Muslim country, with few graduates practicing outside the Middle East. However, pig production, management, and health (PPMH) education is increasingly recognized as needed to meet the requirements to obtain European Association of Establishments for Veterinary Education (EAEVE) accreditation. This study assessed the introduction of pig-related teaching into JUST's veterinary curriculum and student perceptions of this content. A teaching intervention consisted of lectures, group sessions, and a virtual reality (VR) tour of a pig production (PP) unit. To ascertain participants' level of understanding of PPMH, perceptions of different teaching styles, and changes in perception and understanding of the topics, they answered a survey before and after the intervention. Students' knowledge of PP, husbandry, and perceived importance of PP awareness increased significantly, with 90% (n = 17) agreeing that the intervention improved comprehension of the areas mentioned. Participants' interest in PPMH learning increased, with 75% (n = 14) stating they would want to learn more about the topic. VR was significantly ranked the most useful in terms of learning (p = .029), and all participants stated the VR tour had a positive impact on their learning experience. Based on the findings, the focus of pig-related teaching in settings with limited awareness because of sociocultural reasons should be directed toward student-led exercises, group work, and use of technology such as VR. As a result of this intervention, blended PP has now been introduced to the JUST Veterinary curriculum.

13.
Int J Infect Dis ; 122: 107-111, 2022 Sep.
Article in English | MEDLINE | ID: mdl-35640830

ABSTRACT

We explain research gaps on Monkeypox (MPX) virus epidemiology in endemic countries and present hypotheses for the recent increase of MPX cases in West Africa as a possible explanation for the current epidemic in Europe, America, and Australia. The detection of >400 MPX cases in less than a month in May 2022, across many countries underscores the epidemic potential of MPX in humans and demonstrates several important research gaps. First, the true burden of MPX in West and Central Africa is poorly understood, although it is critical for prevention and control of future outbreaks. Second, the diversity and extent of the animal reservoir remain unknown. We hypothesize that the synanthropic rodent population has increased in recent years in Africa leading to more human-rodent interactions and thus increased transmission of MPXV. We further hypothesise that nearly 45 years after the end of routine smallpox vaccination, the larger and more interconnected immune-naïve population has crossed a threshold resulting in more sustainable human-to-human transmission of MPXV. The current epidemic in the Western World is possibly a consequence of increased local transmission of MPXV in Africa. A new estimation of the basic and effective reproduction rate (R0 and Re) in different populations is required. National, regional, and international collaborations are needed to address research gaps related to MPX outbreaks.


Subject(s)
Mpox (monkeypox) , Africa, Central , Animals , Cost of Illness , Disease Outbreaks , Humans , Mpox (monkeypox)/epidemiology , Mpox (monkeypox)/prevention & control , Monkeypox virus , Rodentia
14.
PLoS One ; 17(3): e0264898, 2022.
Article in English | MEDLINE | ID: mdl-35286329

ABSTRACT

Taenia solium is an important cause of acquired epilepsy worldwide and remains endemic in Asia, Africa, and Latin America. Transmission of this parasite is still poorly understood despite the design of infection experiments to improve our knowledge of the disease, with estimates for critical epidemiological parameters, such as the probability of human-to-pig infection after exposure to eggs, still lacking. In this paper, a systematic review was carried out and eight pig infection experiments were analyzed to describe the probability of developing cysts. These experiments included different pathways of inoculation: with ingestion of proglottids, eggs, and beetles that ingested eggs, and direct injection of activated oncospheres into the carotid artery. In these experiments, different infective doses were used, and the numbers of viable and degenerated cysts in the body and brain of each pig were registered. Five alternative dose-response models (exponential, logistic, log-logistic, and exact and approximate beta-Poisson) were assessed for their accuracy in describing the observed probabilities of cyst development as a function of the inoculation dose. Dose-response models were developed separately for the presence of three types of cysts (any, viable only, and cysts in the brain) and considered for each of the four inoculation methods ("Proglottids", "Eggs", "Beetles" and "Carotid"). The exact beta-Poisson model best fit the data for the three types of cysts and all relevant exposure pathways. However, observations for some exposure pathways were too scarce to reliably define a dose-response curve with any model. A wide enough range of doses and sufficient sample sizes was only found for the "Eggs" pathway and a merged "Oral" pathway combining the "Proglottids", "Eggs" and "Beetles" pathways. Estimated parameter values from this model suggest that a low infective dose is sufficient to result in a 50% probability for the development of any cyst or for viable cyst infections. Although this is a preliminary model reliant on a limited dataset, the parameters described in this manuscript should contribute to the design of future experimental infections related to T. solium transmission, as well as the parameterization of simulation models of transmission aimed at informing control.


Subject(s)
Coleoptera , Cysticercosis , Cysts , Swine Diseases , Taenia solium , Animals , Cysticercosis/epidemiology , Swine , Swine Diseases/epidemiology
15.
Transbound Emerg Dis ; 69(3): 1479-1505, 2022 May.
Article in English | MEDLINE | ID: mdl-33876579

ABSTRACT

Brucellosis is regarded as one of the highest burden zoonotic diseases to persist in many regions globally. While sustained vaccination against B. abortus in an endemic setting can markedly reduce the prevalence of large ruminant and human brucellosis and benefit local livelihoods, the implementation of effective and sustainable control programmes has often failed in the worst affected areas. In a cross-sectional study of 728 peri-urban dairy farmers in nine areas of six West and Central African countries, levels of commercialization and farm characteristics were examined alongside B. abortus seroprevalence estimates to hypothesize the most appropriate model for brucellosis vaccination delivery in each country. Demographic and economic data were collated and used to describe the farming systems currently in place. Furthermore, these data were utilized in a likelihood assessment to generate a quantitative score to hypothesize which of three private-public partnership (PPP) vaccine delivery models, that is 1) transformative, 2) transactional or 3) collaborative, would be most appropriate in each setting. The study sites had substantial differences in their levels of dairy commercialization and the farming practices employed; the heterogeneity across the study sites was evident in the conclusions of which models would be appropriate for vaccination delivery. While Lomé (Togo) had a strong indication for a transformative PPP model, Burkina Faso had strong indication for the collaborative PPP model. Of the remaining study sites, the scores were less dominant for any one model with Cameroon and Ivory Coast sites only just scoring highest on the transformative model and Senegal and Mali sites only just scoring highest on the collaborative model. Interestingly, none of the countries included in the study scored highest on the transactional model which currently is the most commonplace delivery model in the majority of sub-Saharan African countries.


Subject(s)
Brucellosis , Africa, Central/epidemiology , Animals , Brucellosis/epidemiology , Brucellosis/prevention & control , Brucellosis/veterinary , Cross-Sectional Studies , Farms , Seroepidemiologic Studies , Vaccination/veterinary
16.
Emerg Infect Dis ; 27(9): 2301-2311, 2021 09.
Article in English | MEDLINE | ID: mdl-34423762

ABSTRACT

After the first detection of Middle East respiratory syndrome coronavirus (MERS-CoV) in camels in Jordan in 2013, we conducted 2 consecutive surveys in 2014-2015 and 2017-2018 investigating risk factors for MERS-CoV infection among camel populations in southern Jordan. Multivariate analysis to control for confounding demonstrated that borrowing of camels, particularly males, for breeding purposes was associated with increased MERS-CoV seroprevalence among receiving herds, suggesting a potential route of viral transmission between herds. Increasing age, herd size, and use of water troughs within herds were also associated with increased seroprevalence. Closed herd management practices were found to be protective. Future vaccination strategies among camel populations in Jordan could potentially prioritize breeding males, which are likely to be shared between herds. In addition, targeted management interventions with the potential to reduce transmission between herds should be considered; voluntary closed herd schemes offer a possible route to achieving disease-free herds.


Subject(s)
Coronavirus Infections , Middle East Respiratory Syndrome Coronavirus , Animals , Camelus , Coronavirus Infections/epidemiology , Coronavirus Infections/veterinary , Jordan/epidemiology , Male , Risk Factors , Seroepidemiologic Studies
17.
Viruses ; 13(5)2021 05 15.
Article in English | MEDLINE | ID: mdl-34063385

ABSTRACT

In foot-and-mouth disease (FMD)-endemic countries, vaccination is commonly used to control the disease, whilst in FMD-free countries, vaccination is considered as an option, in addition to culling the infected and in contact animals. FMD vaccines are mainly comprised of inactivated virions and stimulate protective antibodies to virus structural proteins. In contrast, infection with FMD virus leads to virus replication and additional antibody responses to viral nonstructural proteins (NSP). Therefore, antibodies against NSPs are used to differentiate infection in vaccinated animals (DIVA), in order to estimate the prevalence of infection or its absence. Another advantage of NSP antibody tests is that they detect FMD infection in the field, irrespective of the serotypes of virus in circulation. In cattle, the NSP tests that target the 3ABC polyprotein provides the highest sensitivity, detecting up to 90% of vaccinated animals that become carriers after exposure to infection, with a specificity of around 99%. Due to insufficient diagnostic sensitivity and specificity, detection of a low level of infection is difficult at the population level with a high degree of confidence. The low level of non-specific responses can be overcome by retesting samples scored positive using a second confirmatory test, which should have at least comparable sensitivity to the first test. In this study, six in-house tests were developed incorporating different NSP antigens, and validated using bovine sera from naïve animals, field cases and experimentally vaccinated and/or infected animals. In addition, two (short and long incubation) new commercial NSP tests based on 3ABC competitive blocking ELISAs (ID Screen® FMD NSP Competition, IDvet, France) were validated in this study. The two commercial ELISAs had very similar sensitivities and specificities that were not improved by lengthening the incubation period. Several of the new in-house tests had performance characteristics that were nearly as good as the commercial ELISAs. Finally, the in-house tests were evaluated for use as confirmatory tests following screening with the PrioCHECK® and ID Screen® FMDV NS commercial kits, to assess the diagnostic performance produced by a multiple testing strategy. The in-house tests could be used in series (to confirm) or in parallel (to augment) with the PrioCHECK® and IDvet® FMDV NS commercial kits, in order to improve either the specificity or sensitivity of the overall test system, although this comes at the cost of a reduction in the counterpart (sensitivity/specificity) parameter.


Subject(s)
Antibodies, Viral/immunology , Enzyme-Linked Immunosorbent Assay/standards , Foot-and-Mouth Disease Virus/immunology , Foot-and-Mouth Disease/diagnosis , Foot-and-Mouth Disease/immunology , Vaccination/statistics & numerical data , Vaccination/veterinary , Animals , Antibody Formation , Cattle , Cattle Diseases/diagnosis , Cattle Diseases/epidemiology , Enzyme-Linked Immunosorbent Assay/methods , Sensitivity and Specificity
18.
Viruses ; 13(4)2021 03 31.
Article in English | MEDLINE | ID: mdl-33807288

ABSTRACT

Middle East respiratory syndrome-related coronavirus (MERS-CoV) is a persistent zoonotic pathogen with frequent spillover from dromedary camels to humans in the Arabian Peninsula, resulting in limited outbreaks of MERS with a high case-fatality rate. Full genome sequence data from camel-derived MERS-CoV variants show diverse lineages circulating in domestic camels with frequent recombination. More than 90% of the available full MERS-CoV genome sequences derived from camels are from just two countries, the Kingdom of Saudi Arabia (KSA) and United Arab Emirates (UAE). In this study, we employ a novel method to amplify and sequence the partial MERS-CoV genome with high sensitivity from nasal swabs of infected camels. We recovered more than 99% of the MERS-CoV genome from field-collected samples with greater than 500 TCID50 equivalent per nasal swab from camel herds sampled in Jordan in May 2016. Our subsequent analyses of 14 camel-derived MERS-CoV genomes show a striking lack of genetic diversity circulating in Jordan camels relative to MERS-CoV genome sequences derived from large camel markets in KSA and UAE. The low genetic diversity detected in Jordan camels during our study is consistent with a lack of endemic circulation in these camel herds and reflective of data from MERS outbreaks in humans dominated by nosocomial transmission following a single introduction as reported during the 2015 MERS outbreak in South Korea. Our data suggest transmission of MERS-CoV among two camel herds in Jordan in 2016 following a single introduction event.


Subject(s)
Camelus/virology , Coronavirus Infections/veterinary , Genetic Variation , Middle East Respiratory Syndrome Coronavirus/genetics , Zoonoses/virology , Animals , Coronavirus Infections/epidemiology , Coronavirus Infections/virology , Genome, Viral , Jordan/epidemiology , Middle East Respiratory Syndrome Coronavirus/classification , Middle East Respiratory Syndrome Coronavirus/isolation & purification , Phylogeny , Republic of Korea/epidemiology , Saudi Arabia/epidemiology , United Arab Emirates/epidemiology , Zoonoses/epidemiology
19.
Vet Med Sci ; 7(4): 1254-1262, 2021 07.
Article in English | MEDLINE | ID: mdl-33645902

ABSTRACT

The study was conducted from June to August 2014 in Isiolo Central division of Isiolo Sub-County and Sericho division of Garbatulla Sub-County and comprised two components: (i) a cross-sectional study on the milk-handling hygiene practices, where milk traders' households were the study units and (ii) a case-control study on the risk factors for Brucella spp. infection in humans. Results of the cross-sectional study showed that 26.74% of the respondents never washed their hands before milking, 60.47% never washed the udder before milking and 54.65% never withhold consumption of milk from animals under treatment with antibiotics. The case-control study included household units with previous cases of brucellosis (53.33%) and those without (46.67%) over the previous 5 years and identified drinking of raw milk as the main risk factor for infection (OR = 26.44; 95% CI: 8.04-86.99). Pastoralists' unhygienic handling of milk from production to market is suboptimal and this is due to poor knowledge on hygienic practices, poor knowledge on the risks associated with poor milk hygiene and lack of sufficient and potable water for cleaning of milk containers. Many pastoralists still consume milk raw and this is a major public health risk for milk-borne diseases.


Subject(s)
Brucellosis/veterinary , Farmers/statistics & numerical data , Hygiene/standards , Milk , Animals , Case-Control Studies , Cross-Sectional Studies , Kenya/epidemiology , Risk Factors
20.
PLoS Negl Trop Dis ; 15(3): e0009102, 2021 03.
Article in English | MEDLINE | ID: mdl-33735243

ABSTRACT

Brucellosis is a zoonotic disease imposing significant impacts on livestock production and public health worldwide. India is the world's leading milk producer and Punjab is the state which produces the most cattle and buffalo milk per capita. The aim of this study was to investigate the epidemiology of bovine brucellosis to provide evidence for control of the disease in Punjab State, India. A cross-sectional study of dairy farms was conducted in humans and livestock in rural Ludhiana district using a multi-stage sampling strategy. The study suggests that brucellosis is endemic at high levels in cattle and buffalo in the study area with 15.1% of large ruminants testing seropositive and approximately a third of dairy farms having at least one animal test seropositive. In total, 9.7% of those in direct contact with livestock tested seropositive for Brucella spp. Persons that assisted with calving and/or abortion within the last year on a farm with seronegative livestock and people which did not assist with calving/abortion had 0.35 (95% CI: 0.17 to 7.1) and 0.21 (0.09 to 0.46) times the odds of testing seropositive compared to persons assisting with calving/abortion in a seropositive farm, respectively. The study demonstrated that persons in direct contact with cattle and buffalo in the study area have high risk of exposure to Brucella spp. Control of the disease in livestock is likely to result in benefits to both animal and public health sectors.


Subject(s)
Brucellosis/epidemiology , Brucellosis/veterinary , Buffaloes/microbiology , Cattle Diseases/epidemiology , Cattle/parasitology , Animals , Bacterial Load , Brucella/immunology , Brucellosis/transmission , Cattle Diseases/parasitology , Cross-Sectional Studies , Dairying , Farmers , Humans , India , Livestock/microbiology , Rural Population , Seroconversion , Seroepidemiologic Studies , Serologic Tests
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