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Summary: Mortality data are routinely collected for many livestock and poultry species, and they are often used for epidemiological purposes, including estimating transmission parameters. In this study, we infer transmission rates for African swine fever virus (ASFV), an important transboundary disease of swine, using mortality data collected from nine pig herds in the Russian Federation with confirmed outbreaks of ASFV. Parameters in a stochastic model for the transmission of ASFV within a herd were estimated using approximate Bayesian computation. Estimates for the basic reproduction number varied amongst herds, ranging from 4.4 to 17.3. This was primarily a consequence of differences in transmission rate (range: 0.7–2.2), but also differences in the mean infectious period (range: 4.5–8.3 days). We also found differences amongst herds in the mean latent period (range: 5.8–9.7 days). Furthermore, our results suggest that ASFV could be circulating in a herd for several weeks before a substantial increase in mortality is observed in a herd, limiting the usefulness of mortality data as a means of early detection of an outbreak. However, our results also show that mortality data are a potential source of data from which to infer transmission parameters, at least for diseases which cause high mortality. [ABSTRACT FROM AUTHOR]

Summary: Highly pathogenic avian influenza (HPAI) viruses continue to threaten smallholder poultry producers in several South‐east Asian countries, including Vietnam. In particular, the free‐grazing duck system has been repeatedly highlighted as a major risk factor for HPAI outbreaks. Free‐grazing ducks, which scavenge on rice paddies after the harvest, account for a large proportion of the duck population in Vietnam and the wider South‐east Asian region. However, the structure and dynamics of the free‐grazing duck production from farm to consumption has not been described for Vietnam. In this study, we used a value chain approach to provide a complete picture of the actors involved in the production and marketing of free‐grazing duck eggs and spent layer ducks, as well as to investigate the governance structure of this food system. Group interviews and key informant interviews were conducted in two provinces located in the Mekong River Delta (MRD) and the Red River Delta (RRD). The results presented here highlight similarities and differences in farming and trade practices between the two provinces. The trade of spent layer ducks involved large volumes of live ducks being sent to China and Cambodia for consumption, generating a substantial risk of transboundary spread of pathogens, including HPAI viruses. We describe the major role of “duck yards”, which act as hubs in the northbound trade of spent layer ducks. These yards should be considered as essential links in the value chain of spent layer ducks when considering HPAI surveillance and control. The veterinary authorities are only marginally involved in the value chain activities, and their influence could be strengthened by increasing surveillance activities for instance in duck yards. Last, we discuss the dynamics of the duck value chain and further implications for future HPAI management policies. [ABSTRACT FROM AUTHOR]

African swine fever ( ASF) is a devastating viral disease of swine that is present in both pigs and wild boar in the western part of the Russian Federation and the eastern part of the European Union. It represents a significant threat for the European pig production industry as neither treatment nor vaccine is available. This study analysed the spatial and spatio-temporal distributions of ASF cases that were reported in domestic pigs and wild boar for assessing the likelihood of wild boar-to-domestic pig and farm-to-farm transmission routes in the epidemic that occurred from 2007 to 2014 in the Krasnodar and the Tver regions, two of the most affected areas of the Russian Federation. Results suggest that in both regions, the spatial proximity to an infectious farm was a strong risk factor for infection of a susceptible farm. In the Krasnodar region, the results of the statistical analysis suggest that the epidemics in wild boar and in domestic pigs were independent from each other. In contrast, there seemed to be a dependence between the two epidemics in the Tver region. But because outbreaks in domestic pigs were not statistically significantly clustered around wild boar cases, the joint spatial distribution of wild boar cases and of outbreaks in domestic pigs in the Tver region may be explained by regular spillovers from the domestic pig to the wild boar population. These findings confirm the need to maintain high biosecurity standards on pig farms and justify strict control measures targeted at domestic pig production such as culling of infected herds and local movement restrictions. [ABSTRACT FROM AUTHOR]

In this globalized world, the spread of new, exotic and re-emerging diseases has become one of the most important threats to animal production and public health. This systematic review analyses conventional and novel early detection methods applied to surveillance. In all, 125 scientific documents were considered for this study. Exotic (n = 49) and re-emerging (n = 27) diseases constituted the most frequently represented health threats. In addition, the majority of studies were related to zoonoses (n = 66). The approaches found in the review could be divided in surveillance modalities, both active (n = 23) and passive (n = 5); and tools and methodologies that support surveillance activities (n = 57). Combinations of surveillance modalities and tools (n = 40) were also found. Risk-based approaches were very common (n = 60), especially in the papers describing tools and methodologies (n = 50). The main applications, benefits and limitations of each approach were extracted from the papers. This information will be very useful for informing the development of tools to facilitate the design of cost-effective surveillance strategies. Thus, the current literature review provides key information about the advantages, disadvantages, limitations and potential application of methodologies for the early detection of new, exotic and re-emerging diseases. [ABSTRACT FROM AUTHOR]

Growth in the livestock sector is associated with heightened risk for epidemic diseases. The increasing spillover of new diseases from wildlife is being driven by wide-scale anthropogenic changes allowing for more frequent and closer wildlife-human and wildlife-livestock contacts. An increasing number of epidemics in livestock are associated with rapid transition of livestock systems from extensive to intensive, and local to global movement of livestock and their products through value chain networks with weak biosecurity. Major livestock epidemics in the past two decades have had substantial economic impacts, and the COVID-19 pandemic highlights the devastating socio-economic consequences that spillovers can have when not identified and controlled early in the process of emergence. This highlights the importance of Veterinary Services to integrated, whole-of-society efforts to control infectious diseases in animals. Emphasis within Veterinary Services must be placed on prevention and preparedness. The authors suggest four areas for continued improvement in Veterinary Services to meet this challenge. These are a) continued development of staff capacity for risk assessment and value chain analysis, together with improved policies and communication, b) appropriate adaptation of approaches to prevention and control in resource-poor settings, c) improved multi-sectoral and transboundary cooperation, which enables the sharing of resources and expertise, and d) systematic approaches that enable Veterinary Services to influence decisionmaking for trade, markets, business, public health, and livelihood development at the national and regional levels.

Objective: To evaluate the proportion of non-ambulatory dogs with cervical intervertebral disc herniation (IVDH) in a private clinic and to compare signalment and outcome between those that underwent single or multiple ventral slot decompression (VSD)., Design: Retrospective cohort study., Methods: After screening 43,378 medical records (January 2010-September 2016), those of 185 dogs with non-ambulatory tetraparesis or tetraplegia along with cervical IVDH that had undergone single (123) or multiple (62) VSD were included in this study. Data on signalment, preoperative neurological status, location of affected intervertebral disc(s), time to ambulation and short-term outcome were compared between single and multiple VSD groups., Results: The proportion of non-ambulatory dogs with IVDH was 35.3%. The prevalence of non-ambulation was higher in male dogs (0.56%) than in female dogs (0.26%; P < 0.001) and in neutered dogs than in unneutered dogs (0.51% and 0.27%, respectively, P < 0.001). After surgery, 96.2% of the dogs reached ambulatory status. Dogs with multiple IVDH were older than those with single IVDH. Sex, neutering status or size did not affect the outcome or ambulation status postsurgery. The Pekingese was the most commonly affected breed in both groups. There was no difference in the time to reach ambulation and the presence of neurological deficits after surgery between dogs that underwent single and multiple VSD., Conclusions: In this cohort, dogs undergoing multiple VSD had a good postoperative outcome, and their short-term functional recovery was equal to that of dogs undergoing single ventral slot compression., (© 2020 Australian Veterinary Association.)

A facultative post market monitoring of potential health impacts of genetically modified (GM) feedstuffs on livestock consuming these feeds after pre-market risk assessment is under ongoing consideration. Within the IPAFEED database, scientific studies on health effects beyond performance in livestock and the results of a systematic search for evidence of outcome effects due to GM feed are consolidated. These outcomes were reviewed and checked for consistency in order to identify plausible syndromes suitable for conducting surveillance. The 24 selected studies showed no consistent changes in any health parameter. There were no repeated studies in any species by GM crop type and animal species. As such, there is insufficient evidence to inform the design of surveillance systems for detecting known adverse effects. Animal health surveillance systems have been proposed for the post market monitoring of potential adverse effects in animals. Such systems were evaluated for their applicability to the detection of hypothetical adverse effects and their strengths and weaknesses to detect syndromes of concern are presented. For known adverse effects, applied controlled post-market studies may yield conclusive and high-quality evidence. For detecting unknown adverse effects, the use of existing surveillance systems may still be of interest. A simulation tool developed within the project can be adapted and applied to existing surveillance systems to explore their applicability to the detection of potential adverse effects of GM feed., (Copyright © 2018. Published by Elsevier Ltd.)

Background: Since its first report in 2007, avian influenza (AI) has been endemic in Bangladesh. While live poultry marketing is widespread throughout the country and known to influence AI dissemination and persistence, trading patterns have not been described. The aim of this study is to assess poultry trading practices and features of the poultry trading networks which could promote AI spread, and their potential implications for disease control and surveillance. Data on poultry trading practices was collected from 849 poultry traders during a cross-sectional survey in 138 live bird markets (LBMs) across 17 different districts of Bangladesh. The quantity and origins of traded poultry were assessed for each poultry type in surveyed LBMs. The network of contacts between farms and LBMs resulting from commercial movements of live poultry was constructed to assess its connectivity and to identify the key premises influencing it., Results: Poultry trading practices varied according to the size of the LBMs and to the type of poultry traded. Industrial broiler chickens, the most commonly traded poultry, were generally sold in LBMs close to their production areas, whereas ducks and backyard chickens were moved over longer distances, and their transport involved several intermediates. The poultry trading network composed of 445 nodes (73.2% were LBMs) was highly connected and disassortative. However, the removal of only 5.6% of the nodes (25 LBMs with the highest betweenness scores), reduced the network's connectedness, and the maximum size of output and input domains by more than 50%., Conclusions: Poultry types need to be discriminated in order to understand the way in which poultry trading networks are shaped, and the level of risk of disease spread that these networks may promote. Knowledge of the network structure could be used to target control and surveillance interventions to a small number of LBMs.

The term 'biosecurity' encompasses many measures farmers can take to reduce the risk of pathogen incursion or spread. As the best strategy will vary between settings, veterinarians play an important role in assessing risk and providing advice, but effectiveness requires farmer acceptance and implementation. The aim of this study was to assess the effectiveness of specifically-tailored biosecurity advice packages in reducing endemic pathogen presence on UK beef suckler farms. One hundred and sixteen farms recruited by 10 veterinary practices were followed for three years. Farms were randomly allocated to intervention (receiving specifically-tailored advice, with veterinarians and farmers collaborating to develop an improved biosecurity strategy) or control (receiving general advice) groups. A spreadsheet-based tool was used annually to attribute a score to each farm reflecting risk of entry or spread of bovine viral diarrhoea virus (BVDV), bovine herpesvirus-1 (BHV1), Mycobacterium avium subsp. paratuberculosis (MAP), Leptospira interrogans serovar hardjo (L. hardjo) and Mycobacterium bovis (M. bovis). Objectives of these analyses were to identify evidence of reduction in risk behaviours during the study, as well as evidence of reductions in pathogen presence, as indications of effectiveness. Risk behaviours and pathogen prevalences were examined across study years, and on intervention compared with control farms, using descriptive statistics and multilevel regression. There were significant reductions in risk scores for all five pathogens, regardless of intervention status, in every study year compared with the outset. Animals on intervention farms were significantly less likely than those on control farms to be seropositive for BVDV in years 2 and 3 and for L. hardjo in year 3 of the study. Variations by study year in animal-level odds of seropositivity to BHV1 or MAP were not associated with farm intervention status. All farms had significantly reduced odds of BHV1 seropositivity in year 2 than at the outset. Variations in farm-level MAP seropositivity were not associated with intervention status. There were increased odds of M. bovis on intervention farms compared with control farms at the end of the study. Results suggest a structured annual risk assessment process, conducted as a collaboration between veterinarian and farmer, is valuable in encouraging improved biosecurity practices. There were some indications, but not conclusive evidence, that tailored biosecurity advice packages have potential to reduce pathogen presence. These findings will inform development of a collaborative approach to biosecurity between veterinarians and farmers, including adoption of cost-effective strategies effective across pathogens., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Reporting of observational studies in veterinary research presents challenges that often are not addressed in published reporting guidelines. Our objective was to develop an extension of the STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) statement that addresses unique reporting requirements for observational studies in veterinary medicine related to health, production, welfare, and food safety. We conducted a consensus meeting with 17 experts in Mississauga, Canada. Experts completed a premeeting survey about whether items in the STROBE statement should be modified or added to address unique issues related to observational studies in animal species with health, production, welfare, or food safety outcomes. During the meeting, each STROBE item was discussed to determine whether or not rewording was recommended, and whether additions were warranted. Anonymous voting was used to determine consensus. Six items required no modifications or additions. Modifications or additions were made to the STROBE items 1 (title and abstract), 3 (objectives), 5 (setting), 6 (participants), 7 (variables), 8 (data sources and measurement), 9 (bias), 10 (study size), 12 (statistical methods), 13 (participants), 14 (descriptive data), 15 (outcome data), 16 (main results), 17 (other analyses), 19 (limitations), and 22 (funding). The methods and processes used were similar to those used for other extensions of the STROBE statement. The use of this STROBE statement extension should improve reporting of observational studies in veterinary research by recognizing unique features of observational studies involving food-producing and companion animals, products of animal origin, aquaculture, and wildlife.

The STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) statement was first published in 2007 and again in 2014. The purpose of the original STROBE was to provide guidance for authors, reviewers, and editors to improve the comprehensiveness of reporting; however, STROBE has a unique focus on observational studies. Although much of the guidance provided by the original STROBE document is directly applicable, it was deemed useful to map those statements to veterinary concepts, provide veterinary examples, and highlight unique aspects of reporting in veterinary observational studies. Here, we present the examples and explanations for the checklist items included in the STROBE-Vet statement. Thus, this is a companion document to the STROBE-Vet statement methods and process document (JVIM&#95;14575 "Methods and Processes of Developing the Strengthening the Reporting of Observational Studies in Epidemiology-Veterinary (STROBE-Vet) Statement" undergoing proofing), which describes the checklist and how it was developed., (Copyright © 2016 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.)

Fasciolosis, amphistomosis and schistosomosis, transmitted by the freshwater snail species Indoplanorbis and Lymnaea , are important snail-borne diseases in India as they affect the entire spectrum of domestic animals causing substantial mortality and economic loss. Identifying any heterogeneity in the spatial distribution of these snail-borne diseases will allow for targeted disease control and efficient use of resources. The objectives of this study were threefold: (i) to describe and explore the spatial distribution of Indoplanorbis and Lymnaea in Rohtak and Jhajjar districts of Haryana, India (ii) to identify factors associated with occurrence of these freshwater snail species and (iii) to produce a map showing the predicted risk of occurrence of Lymnaea and Indoplanorbis spp. in the study area. Snails were collected from water bodies of 99 settlements out of a total of 453 in the study area. Kernel smoothing was used to generate a kernel ratio map while Kulldorff's spatial scan statistic was used to detect clusters of settlements with a high/low risk. Multivariable logistic regression showed that snails were almost ten times more likely to be present in rice-growing areas than in those not growing rice (OR 9.24) and that snails were less likely to be present with each 1 km increase in distance from a canal (OR 0.86). The regression model was used to produce a map illustrating the predicted risk of snail occurrence. Since the distribution of vector snails mirrors the distribution of snail-borne parasitic diseases, such spatial analysis helps to determine the relative risk of snail-infestation as well as snail-borne diseases' distribution and planning of control activities.

Taenia solium cysticercosis was reported in official veterinary and medical statistics to be highly prevalent in pigs and humans in Madagascar, but few estimates are available for pigs. This study aimed to estimate the seroprevalence of porcine cysticercosis among pigs slaughtered in Antananarivo abattoirs. Firstly, the diagnostic performance of two antigen-ELISA techniques (B158B60 Ag-ELISA and HP10 Ag-ELISA) and an immunoblotting method were compared with meat inspection procedures on a sample of pigs suspected to be infected with (group 1; n=250) or free of (group 2; n=250) T. solium based on direct veterinary inspection in Madagascar. Sensitivity and specificity of the antigen ELISAs were then estimated using a Bayesian approach for detection of porcine cysticercosis in the absence of a gold standard. Then, a third set of pig sera (group 3, n=250) was randomly collected in Antananarivo slaughterhouses and tested to estimate the overall prevalence of T. solium contamination in pork meat traded in Antananarivo. The antigen ELISAs showed a high sensitivity (>84%), but the B158B60 Ag-ELISA appeared to be more specific than the HP10 Ag-ELISA (model 1: 95% vs 74%; model 2: 87% vs 71%). The overall prevalence of porcine cysticercosis in Antananarivo slaughterhouses was estimated at 2.3% (95% credibility interval [95%CrI]: 0.09-9.1%) to 2.6% (95%CrI: 0.1-10.3%) depending on the model and priors used. Since the sample used in this study is not representative of the national pig population, village-based surveys and longitudinal monitoring at slaughter are needed to better estimate the overall prevalence, geographical patterns and main risk factors for T. solium contamination, in order to improve control policies., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Despite years of biannual mass vaccination of cattle, foot-and-mouth disease (FMD) remains uncontrolled in Anatolian Turkey. To evaluate protection after mass vaccination we measured post-vaccination antibodies in a cohort of cattle (serotypes O, A and Asia-1). To obtain results reflecting typical field protection, participants were randomly sampled from across Central and Western Turkey after routine vaccination. Giving two-doses one month apart is recommended when cattle are first vaccinated against FMD. However, due to cost and logistics, this is not routinely performed in Turkey, and elsewhere. Nested within the cohort, we conducted a randomised trial comparing post-vaccination antibodies after a single-dose versus a two-dose primary vaccination course. Four to five months after vaccination, only a third of single-vaccinated cattle had antibody levels above a threshold associated with protection. A third never reached this threshold, even at peak response one month after vaccination. It was not until animals had received three vaccine doses in their lifetime, vaccinating every six months, that most (64% to 86% depending on serotype) maintained antibody levels above this threshold. By this time cattle would be >20 months old with almost half the population below this age. Consequently, many vaccinated animals will be unprotected for much of the year. Compared to a single-dose, a primary vaccination course of two-doses greatly improved the level and duration of immunity. We concluded that the FMD vaccination programme in Anatolian Turkey did not produce the high levels of immunity required. Higher potency vaccines are now used throughout Turkey, with a two-dose primary course in certain areas. Monitoring post-vaccination serology is an important component of evaluation for FMD vaccination programmes. However, consideration must be given to which antigens are present in the test, the vaccine and the field virus. Differences between these antigens affect the relationship between antibody titre and protection., (Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.)