Novel Hendra Virus Variant Detected by Sentinel Surveillance of Horses in Australia.

We identified and isolated a novel Hendra virus (HeV) variant not detected by routine testing from a horse in Queensland, Australia, that died from acute illness with signs consistent with HeV infection. Using whole-genome sequencing and phylogenetic analysis, we determined the variant had ≈83% nt identity with prototypic HeV. In silico and in vitro comparisons of the receptor-binding protein with prototypic HeV support that the human monoclonal antibody m102.4 used for postexposure prophylaxis and current equine vaccine will be effective against this variant. An updated quantitative PCR developed for routine surveillance resulted in subsequent case detection. Genetic sequence consistency with virus detected in grey-headed flying foxes suggests the variant circulates at least among this species. Studies are needed to determine infection kinetics, pathogenicity, reservoir-species associations, viral-host coevolution, and spillover dynamics for this virus. Surveillance and biosecurity practices should be updated to acknowledge HeV spillover risk across all regions frequented by flying foxes.

Design and Evaluation of the Veterinary Epidemiology Teaching Skills (VETS) Workshop: Building Capacity in the Asia-Pacific Region.

Building workforce capacity in epidemiology skills for veterinarians in the Asia-Pacific region is crucial to health security. However, successful implementation of these programs requires a supply of trained veterinary epidemiology teachers and mentors. We sought to design and evaluate delivery of a 4-day Veterinary Epidemiology Teaching Skills (VETS) workshop as part of a larger project to strengthen field veterinary epidemiology capacity. Thirty-five veterinarians were selected to participate in the 4-day VETS workshop, consisting of nine modules delivered synchronously online. Participants were formatively assessed and given feedback from peers and facilitators on all activities. Data were collected with pre- and post-course questionnaires. Numeric values were categorized to convert into an ordinal scale with four categories. Qualitative data were analyzed using thematic analysis. Thirty-four veterinary epidemiologists from eight countries of the Asia-Pacific completed the workshop. Participants felt able to achieve most key learning outcomes through provision of succinct literature, teaching frameworks, and active participation in small groups, with multiple opportunities to give and receive feedback. Although the online workshop provided flexibility, participants felt the addition of face-to-face sessions would enrich their experience. Additionally, protected time from work duties would have improved their ability to fully engage in the workshop. The VETS workshop granted an effective online framework for veterinary epidemiologists to develop and practice skills in teaching, facilitation, assessment, feedback, case-based learning, program evaluation, and mentorship. A challenge will be ensuring provision of local teaching and mentoring opportunities to reinforce learning outcomes and build workforce capacity.

Detection of ostreid herpesvirus-1 in plankton and seawater samples at an estuary scale.

Ostreid herpesvirus-1 (OsHV-1) is known to associate with particles in seawater, leading to infection and disease in the Pacific oyster Crassostrea gigas. The estuarine environment is highly complex and changeable, and this needs to be considered when collecting environmental samples for pathogen detection. The aims of this study were to (1) compare different aspects of collecting natural seawater and plankton samples for detection of OsHV-1 DNA and (2) determine whether detection of OsHV-1 DNA in such environmental samples has merit for disease risk prediction. The results of one experiment suggest that sampling on the outgoing tide may improve the detection of OsHV-1 DNA in seawater and plankton tow samples (odds ratio 2.71). This statistical comparison was not possible in 2 other experiments. The method (plankton tow or beta bottle) and depth of collection (range: 250-1250 mm) had no effect on the likelihood of detection of OsHV-1. OsHV-1 DNA was found at low concentrations in plankton tow and seawater samples, and only when outbreaks of mortality associated with OsHV-1 were observed in nearby experimental or farmed populations of C. gigas. This suggests that single point in time environmental samples of seawater or plankton are not sufficient to rule out the presence of OsHV-1 in an estuary. The association of OsHV-1 with particles in seawater needs to be better understood in order to determine whether more selective and sensitive methods can be devised to detect it, before environmental samples can be reliably used in disease risk prediction.

Control of paratuberculosis: who, why and how. A review of 48 countries.

Paratuberculosis, a chronic disease affecting ruminant livestock, is caused by Mycobacterium avium subsp. paratuberculosis (MAP). It has direct and indirect economic costs, impacts animal welfare and arouses public health concerns. In a survey of 48 countries we found paratuberculosis to be very common in livestock. In about half the countries more than 20% of herds and flocks were infected with MAP. Most countries had large ruminant populations (millions), several types of farmed ruminants, multiple husbandry systems and tens of thousands of individual farms, creating challenges for disease control. In addition, numerous species of free-living wildlife were infected. Paratuberculosis was notifiable in most countries, but formal control programs were present in only 22 countries. Generally, these were the more highly developed countries with advanced veterinary services. Of the countries without a formal control program for paratuberculosis, 76% were in South and Central America, Asia and Africa while 20% were in Europe. Control programs were justified most commonly on animal health grounds, but protecting market access and public health were other factors. Prevalence reduction was the major objective in most countries, but Norway and Sweden aimed to eradicate the disease, so surveillance and response were their major objectives. Government funding was involved in about two thirds of countries, but operations tended to be funded by farmers and their organizations and not by government alone. The majority of countries (60%) had voluntary control programs. Generally, programs were supported by incentives for joining, financial compensation and/or penalties for non-participation. Performance indicators, structure, leadership, practices and tools used in control programs are also presented. Securing funding for long-term control activities was a widespread problem. Control programs were reported to be successful in 16 (73%) of the 22 countries. Recommendations are made for future control programs, including a primary goal of establishing an international code for paratuberculosis, leading to universal acknowledgment of the principles and methods of control in relation to endemic and transboundary disease. An holistic approach across all ruminant livestock industries and long-term commitment is required for control of paratuberculosis.

Antifungal Susceptibility of the Aspergillus viridinutans Complex: Comparison of Two In Vitro Methods.

Cryptic species of Aspergillus fumigatus, including the Aspergillus viridinutans species complex, are increasingly reported to be causes of invasive aspergillosis. Their identification is clinically relevant, as these species frequently have intrinsic resistance to common antifungals. We evaluated the susceptibilities of 90 environmental and clinical isolates from the A. viridinutans species complex, identified by DNA sequencing of the calmodulin gene, to seven antifungals (voriconazole, posaconazole, itraconazole, amphotericin B, anidulafungin, micafungin, and caspofungin) using the reference European Committee on Antimicrobial Susceptibility Testing (EUCAST) method. The majority of species demonstrated elevated MICs of voriconazole (geometric mean [GM] MIC, 4.46 mg/liter) and itraconazole (GM MIC, 9.85 mg/liter) and had variable susceptibility to amphotericin B (GM MIC, 2.5 mg/liter). Overall, the MICs of posaconazole and the minimum effective concentrations of echinocandins were low. The results obtained by the EUCAST method were compared with the results obtained with Sensititre YeastOne (YO) panels. Overall, there was 67% agreement (95% confidence interval [CI], 62 to 72%) between the results obtained by the EUCAST method and those obtained with YO panels when the results were read at 48 h and 82% agreement (95% CI, 78 to 86%) when the results were read at 72 h. There was a significant difference in agreement between antifungals; agreement was high for amphotericin B, voriconazole, and posaconazole (70 to 86% at 48 h and 88 to 93% at 72 h) but was very low for itraconazole (37% at 48 h and 57% at 72 h). The agreement was also variable between species, with the maximum agreement being observed for A. felis isolates (85 and 93% at 48 and 72 h, respectively). Elevated MICs of voriconazole and itraconazole were cross-correlated, but there was no correlation between the other azoles tested.

Counting the dead to determine the source and transmission of the marine herpesvirus OsHV-1 in Crassostrea gigas.

Marine herpesviruses are responsible for epizootics in economically, ecologically and culturally significant taxa. The recent emergence of microvariants of Ostreid herpesvirus 1 (OsHV-1) in Pacific oysters Crassostrea gigas has resulted in socioeconomic losses in Europe, New Zealand and Australia however, there is no information on their origin or mode of transmission. These factors need to be understood because they influence the way the disease may be prevented and controlled. Mortality data obtained from experimental populations of C. gigas during natural epizootics of OsHV-1 disease in Australia were analysed qualitatively. In addition we compared actual mortality data with those from a Reed-Frost model of direct transmission and analysed incubation periods using Sartwell's method to test for the type of epizootic, point source or propagating. We concluded that outbreaks were initiated from an unknown environmental source which is unlikely to be farmed oysters in the same estuary. While direct oyster-to-oyster transmission may occur in larger oysters if they are in close proximity (< 40 cm), it did not explain the observed epizootics, point source exposure and indirect transmission being more common and important. A conceptual model is proposed for OsHV-1 index case source and transmission, leading to endemicity with recurrent seasonal outbreaks. The findings suggest that prevention and control of OsHV-1 in C. gigas will require multiple interventions. OsHV-1 in C. gigas, which is a sedentary animal once beyond the larval stage, is an informative model when considering marine host-herpesvirus relationships.

Experimental infections of Pacific oyster Crassostrea gigas using the Australian ostreid herpesvirus-1 (OsHV-1) µVar strain.

In Australia, the spread of the ostreid herpesvirus-1 microvariant (OsHV-1 µVar) threatens the Pacific oyster industry. There is an urgent need to develop an experimental infection model in order to study the pathogenesis of the virus under controlled laboratory conditions. The present study constitutes the first attempt to use archived frozen oysters as a source of inoculum, based on the Australian OsHV-1 µVar strain. Experiments were conducted to test (1) virus infectivity, (2) the dose-response relationship for OsHV-1, and (3) the best conditions in which to store infective viral inoculum. Intramuscular injection of a viral inoculum consistently led to an onset of mortality 48 h post-injection and a final cumulative mortality exceeding 90%, in association with high viral loads (1 × 105 to 3 × 107 copies of virus mg-1) in dead individuals. For the first time, an infective inoculum was produced from frozen oysters (tissues stored at -80°C for 6 mo). Storage of purified viral inoculum at +4°C for 3 mo provided similar results to use of fresh inoculum, whereas storage at -20°C, -80°C and room temperature was detrimental to infectivity. A dose-response relationship for OsHV-1 was identified but further research is recommended to determine the most appropriate viral concentration for development of infection models that would be used for different purposes. Overall, this work highlights the best practices and potential issues that may occur in the development of a reproducible and transferable infection model for studying the pathogenicity of the Australian OsHV-1 strain in Crassostrea gigas under experimental conditions.

Environmental survival of Mycobacterium avium subsp. paratuberculosis in different climatic zones of eastern Australia.

The duration of survival of both the S and C strains of Mycobacterium avium subsp. paratuberculosis in feces was quantified in contrasting climatic zones of New South Wales, Australia, and detailed environmental temperature data were collected. Known concentrations of S and C strains in feces placed on soil in polystyrene boxes were exposed to the environment with or without the provision of shade (70%) at Bathurst, Armidale, Condobolin, and Broken Hill, and subsamples taken every 2 weeks were cultured for the presence of M. avium subsp. paratuberculosis. The duration of survival ranged from a minimum of 1 week to a maximum of 16 weeks, and the provision of 70% shade was the most important factor in extending the survival time. The hazard of death for exposed compared to shaded samples was 20 and 9 times higher for the S and C strains, respectively. Site did not affect the survival of the C strain, but for the S strain, the hazard of death was 2.3 times higher at the two arid zone sites (Broken Hill and Condobolin) than at the two temperate zone sites (Bathurst and Armidale). Temperature measurements revealed maximum temperatures exceeding 60°C and large daily temperature ranges at the soil surface, particularly in exposed boxes.

The use of a modified Delphi approach to engage stakeholders in zoonotic disease research priority setting.

BACKGROUND: After the 2011 cluster of Hendra virus cases in horses in Australia, public health targeted education initiatives at people in the equine industry to reduce human exposure to potentially infected horses. 'Horse owners and Hendra Virus: A Longitudinal cohort study To Evaluate Risk' aims to enhance public health measures through improved understanding of Hendra virus risk perception and risk mitigation strategies among horse owners and horse care providers. This paper describes the stakeholder consultation that was undertaken to ensure the cohort study outcomes were relevant to diverse groups who play a role in Hendra virus policy development and implementation. METHODS: A two-round modified Delphi study with online questionnaires was conducted. In round one, stakeholders identified priority research areas. In round two, stakeholders rated and ranked topics that emerged from thematic analysis of the round one responses. Round two data were analysed using logistic regression. RESULTS: Of the 255 stakeholders contacted, 101 responded to round one. Over 450 topics were proposed. These were organized into 18 themes. Approximately two thirds of the round one respondents participated in round two. 'Hendra virus-related risk awareness and perception', 'personal health and safety', 'emergency preparedness', 'risk prevention, mitigation, and biosecurity', and 'Hendra virus vaccination in horses--attitudes/uptake' were the top five areas identified according to probability of being ranked extremely important. CONCLUSIONS: In this study, a modified Delphi approach was effective in guiding research into Hendra virus, a zoonotic disease of animal and human health significance. The findings support the notion that stakeholders should be engaged in zoonotic disease research priority setting. Such consultation will help to ensure that research initiatives are relevant and useful to stakeholders in the position to make use of new findings.

Capacity and needs assessment of veterinary services in Vietnam in biosecurity, biosafety and One Health.

The Asia-Pacific region is recognised as an epicentre of emerging infectious diseases (EIDs), of which 75% are zoonotic in nature. Vietnam is recognised as a potential hotspot for zoonotic EIDs. There is a growing recognition that progress towards global health security requires greater focus on collaboration between the human health and animal health sectors to control diseases at their animal source and prevent against human health impacts. Assessment of veterinary epidemiology capacity in Vietnam is paramount to strengthening the health security of Asia-Pacific. This study aims to evaluate the national capacity and needs of veterinary services in Vietnam in biosecurity, biosafety and One Health. A cross-sectional, convergent mixed-methods study was conducted between November 2020 and April 2021. An online questionnaire was administered to government-employed field veterinarians. Descriptive analyses and logistic regression models were performed using survey responses to understand capacity in the field. Semi-structured interviews were also conducted with stakeholders in veterinary services including government, academia, research institutes, non-profit and international organisations. Coding and thematic analysis using a deductive approach was used for data collected from interviews to contextualise findings from the survey and understand institutional capacity. In total, 178 field veterinarians completed the online survey and 25 stakeholders were interviewed. The majority of participants had reported receiving training in biosecurity and biosafety, including use of personal protective equipment. Most respondents reported practicing good biosecurity measures (92%) and good biosafety measures (88%). Physical and socioeconomic barriers to practicing biosecurity were reported to be prevalent for smallholder farmers, which may suggest a gap in the capacity of veterinary services to provide cost-effective and practical biosecurity strategies. Seventy five percent of participants had never or rarely participated in One Health approaches in the field in the last 12 months and 69% reported further training as a high priority. There was a knowledge gap reported amongst district and commune-level veterinary staff about the need for, and awareness of multisectoral collaboration. Respondents that completed postgraduate qualifications in epidemiology or Field Epidemiology Training Programs (adjusted OR: 3.06; 95% CI: 1.01, 9.23, p = 0.046) and had longer job tenure between 10-12 years (OR: 10.38; 95% CI: 3.06, 35.15, p = <0.001) were more likely to have higher levels of experience in One Health. This study identified gaps in knowledge, attitudes and adoption of practices related to biosecurity, biosafety and One Health specifically in lower-level or less experienced veterinary staff without further training opportunities in epidemiology. These findings enable prioritisation of training, policy, and planning activities to further enhance the national capacity of veterinary services in Vietnam.

Perceptions of vulnerability to a future outbreak: a study of horse managers affected by the first Australian equine influenza outbreak.

BACKGROUND: A growing body of work shows the benefits of applying social cognitive behavioural theory to investigate infection control and biosecurity practices. Protection motivation theory has been used to predict protective health behaviours. The theory outlines that a perception of a lack of vulnerability to a disease contributes to a reduced threat appraisal, which results in poorer motivation, and is linked to poorer compliance with advised health protective behaviours. This study, conducted following the first-ever outbreak of equine influenza in Australia in 2007, identified factors associated with horse managers' perceived vulnerability to a future equine influenza outbreak. RESULTS: Of the 200 respondents, 31.9% perceived themselves to be very vulnerable, 36.6% vulnerable and 31.4% not vulnerable to a future outbreak of equine influenza. Multivariable logistic regression modelling revealed that managers involved in horse racing and those on rural horse premises perceived themselves to have low levels of vulnerability. Managers of horse premises that experienced infection in their horses in 2007 and those seeking infection control information from specific sources reported increased levels of perceived vulnerability to a future outbreak. CONCLUSION: Different groups across the horse industry perceived differing levels of vulnerability to a future outbreak. Increased vulnerability contributes to favourable infection control behaviour and hence these findings are important for understanding uptake of recommended infection control measures. Future biosecurity communication strategies should be delivered through information sources suitable for the horse racing and rural sectors.

Spatial distribution of mortality in Pacific oysters Crassostrea gigas: reflection on mechanisms of OsHV-1 transmission.

The ostreid herpesvirus OsHV-1 has the potential to devastate Pacific oyster Crassostrea gigas culture in Australia as it has done in many other countries, highlighting the need for a better understanding of disease expression and transmission. The aim of this study was to assess the spatial distribution of OsHV-1-associated mortalities in one of only two infected areas in Australia, Woolooware Bay (Botany Bay, New South Wales). In October 2011, healthy sentinel Pacific oysters were placed in 3 different locations at 3 different tidal levels, and OsHV-1 associated mortalities were closely monitored over 7 mo. The outbreak started in November 2011, and the disease remained active until April 2012. Three major mortality events were detected. Rather than being a propagating epizootic, it appeared that most oysters were infected from a common environmental source. The distribution of OsHV-1-associated mortalities was spatially clustered, highly variable and clearly dependent on the age of oysters and their position in the water column. Non-random distribution of mortalities at macro scale (sites several km apart) and micro scale (within rearing trays), and vertical clustering patterns in the water column are discussed in regard to factors known to influence mechanism of disease transmission in aquatic environments (hydrodynamics, physical disturbances, host density/distribution, and variations of environmental parameters). A new hypothesis proposing that OsHV-1 may be carried through water by particles, possibly plankton, is also suggested to explain the patchy distribution of mortalities in Woolooware Bay.

Host characteristics and their influence on zoonosis, disease emergence and multi-host pathogenicity.

The interplay between agent-host-environment characteristics is responsible for the emergence and zoonotic potential of infectious disease pathogens. Many studies have investigated key agent characteristics and environmental factors responsible for these phenomena. However, little is known about the role played by host characteristics in zoonoses, disease emergence and the ability of pathogens to infect multiple hosts. We compiled a dataset of 8114 vertebrate host-agent interactions from published literature. Multiple host characteristics and the pathogen's zoonotic, emergence and multi-host potential were then linked to the dataset. The associations between zoonotic, emerging human pathogen and multi-host pathogenicity and several host characteristics were explored using logistic regression models. The numbers of publications and sequences from the agent-host combinations were used to control for the research effort. Hosts in the class Aves (odds ratio [OR] 20.87, 95% CI 2.66-163.97) and Mammalia (OR 26.09, 95% CI 3.34-203.87) were more likely to host a zoonotic pathogen compared to the class Amphibia. Similarly, hosts having Bursa fabricii (i.e., birds) (OR 1.8, 95% CI 1.4-2.3) were more likely to host an emerging human pathogen. The odds of being a zoonotic pathogen were highest when the host female required a greater number of days for maturity, and the pathogen was able to affect a greater number of host species. In contrast, the hosts from which a higher number of pathogens were reported were less likely (OR 0.39, 95% CI 0.31-0.49) to be associated with an emerging human pathogen. The odds of an emerging human pathogen were highest when the host had a higher adult body mass, and the specific pathogen could affect more host species. The odds of a pathogen infecting multiple hosts were highest when a host had shorter female maturity days (>670-2830 days) and lower birth/hatching weight (>42.2-995 g) compared to longer female maturity days (>2830-6940 days) and greater birth/hatching weight (>3.31-1160 kg). We conclude that several host characteristics - such as mass, maturity, immune system and pathogen permissiveness- are linked with zoonoses, disease emergence or multi-host pathogenicity. These findings can contribute to preparedness for emerging infections and zoonotic diseases.

A randomised control trial to evaluate the effectiveness of a commercial vaccine for pinkeye in Australian beef cattle.

Pinkeye (a generic term to describe infectious bovine keratoconjunctivitis) is a significant disease of cattle worldwide, impacting productivity and animal welfare. One commercial pinkeye vaccine, a systematically administered Moraxella bovis bacterin, has been available in Australia since 2007. This is the first field trial of the effectiveness of this vaccine for the prevention of naturally occurring disease in Australia. Extensively run beef herds in southwest Queensland that regularly experienced pinkeye were enrolled in the trial and animals were randomly allocated to vaccinated and control groups in different proportions in each herd. The subsequent incidence of clinical pinkeye between the two groups was compared for animals less than one-year-old. Data were analysed from 649 cattle from five herds over two pinkeye seasons: three herds of 390 calves from 1st November 2019 to 20th January 2020 and two herds of 259 calves from 23rd September 2020 to 21st April 2021. Pinkeye was common with 24% of all calves (156/649) contracting the disease during the trial. Univariable and multivariable binary logistic mixed-effect models were fitted to account for clustered data and potential residual confounding due to sex, weight, breed, coat colour, and periocular pigmentation. The incidence of pinkeye was not significantly different between vaccinated and control groups, both alone (p = 0.67) and after adjusting for sex and weight differences (p = 0.69). The vaccine was not protective against naturally occurring pinkeye under the field conditions.

One Health activities to reinforce intersectoral coordination at local levels in India.

India's dense human and animal populations, agricultural economy, changing environment, and social dynamics support conditions for emergence/re-emergence of zoonotic diseases that necessitate a One Health (OH) approach for control. In addition to OH national level frameworks, effective OH driven strategies that promote local intersectoral coordination and collaboration are needed to truly address zoonotic diseases in India. We conducted a literature review to assess the landscape of OH activities at local levels in India that featured intersectoral coordination and collaboration and supplemented it with our own experience conducting OH related activities with local partners. We identified key themes and examples in local OH activities. Our landscape assessment demonstrated that intersectoral collaboration primarily occurs through specific research activities and during outbreaks, however, there is limited formal coordination among veterinary, medical, and environmental professionals on the day-to-day prevention and detection of zoonotic diseases at district/sub-district levels in India. Examples of local OH driven intersectoral coordination include the essential role of veterinarians in COVID-19 diagnostics, testing of human samples in veterinary labs for Brucella and leptospirosis in Punjab and Tamil Nadu, respectively, and implementation of OH education targeted to school children and farmers in rural communities. There is an opportunity to strengthen local intersectoral coordination between animal, human and environmental health sectors by building on these activities and formalizing the existing collaborative networks. As India moves forward with broad OH initiatives, OH networks and experience at the local level from previous or ongoing activities can support implementation from the ground up.

Development of core competencies for field veterinary epidemiology training programs.

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.

Geodemography, environment and societal characteristics drive the global diversity of emerging, zoonotic and human pathogens.

Understanding human disease, zoonoses and emergence is a global priority. A deep understanding of pathogen ecology and the complex inherent relationships at the agent-environment interface are essential to inform disease control and mitigation and to predict the next zoonotic pandemic. Here, we present the first analysis of social and environmental factors associated with human, zoonotic and emerging pathogen diversity at a global scale, controlling for research effort. Predictor-response associations were captured by generalized additive models. We used national level data to aid in policy development to inform control and mitigation. We show that human population density, land area, temperature and the human development index at the country level are associated with human, emerging and zoonotic pathogen diversity. Multiple models demonstrating society-agent-environment interactions demonstrate that social, environmental and geographical factors predict global pathogen diversity. The analyses demonstrate that weather variables (temperature and rainfall) have the potential to influence pathogen diversity.

Inherent virus characteristics and host range drive the zoonotic and emerging potential of viruses.

Understanding the zoonotic and emerging potential of viruses is critical to prevent and control spread that can cause disease epidemics or pandemics. We developed a database using the most up-to-date information from the International Committee on Taxonomy of Viruses (4958 virus species) and identified 1479 vertebrate virus species and their host ranges. Viral traits and host ranges were then used as predictors in generalized linear mixed models for three host-associated outcomes - confirmed zoonotic, potential zoonotic and disease emergence. We identified significant interactions between host range and viral characteristics, not previously reported, that influence the zoonotic and emergence potential of viruses. Bat- and livestock-adapted viruses posed high risk, and the risk increased substantially if these viruses were also present in other vertebrates or were not reported from invertebrates. Our model predicted 39 viruses of interest that have never been reported to have zoonotic potential (27) or to potentially become emerging human viruses (12). We conclude that nucleic acid type is important in identifying the zoonotic and emerging potential of viruses. We recommend enhanced surveillance and monitoring of these virus species identified with a zoonotic and emerging potential to mitigate disease outbreaks and future epidemics.

Evaluation of the sensitivity and specificity of three diagnostic tests for Coxiella burnetii infection in cattle and buffaloes in Punjab (India) using Bayesian latent class analysis.

Q Fever is a zoonotic disease of significant animal and public health concern, caused by Coxiella burnetii (C. burnetii), an obligate intracellular bacterium. This study was done to evaluate the diagnostic sensitivity (DSe) and diagnostic specificity (DSp) of three diagnostic methods to diagnose C. burnetii infection in cattle and buffaloes in Punjab, India: an indirect ELISA method applied in serum samples and a trans-Polymerase Chain Reaction (trans-PCR) technique applied in milk samples and genital swabs, using a Bayesian latent class analysis. Conditional independence was assumed between the tests, given (i) the different biological principle of ELISA and trans-PCR and (ii) the fact that the trans-PCR was performed on different tissues. The ELISA method in the serum samples showed the highest DSe of 0.97 (95% Probability Intervals (PIs): 0.93; 0.99) compared to the trans-PCR method applied in milk samples 0.76 (0.63; 0.87) and genital swabs 0.73 (0.58; 0.85). The DSps of all tests were high, with trans-PCR in genital swabs recording the highest DSp of 0.99 (0.98; 1), while the DSp of trans-PCR in milk samples and ELISA in serum samples were 0.97 (0.95; 0.99) and 0.95 (0.93; 0.97) respectively. The study results show that none of the applied tests are perfect, therefore, a testing regimen based on the diagnostic characteristic of the tests may be considered for diagnosis of C. burnetii.