Point of truth calibration for disease prioritisation-A case study of prioritisation of exotic diseases for the pig industry in Australia

The objective of this study was to trial point of truth calibration (POTCal) as a novel method for disease prioritisation. To illustrate the application of this method, we used a previously described case-study of prioritisation of exotic diseases for the pig industry in Australia. Disease scenarios were constructed from criteria which described potential impact and pig-producers were asked to score the importance of each scenario. POTCal was used to model participants' estimates of disease importance as a function of the criteria, to derive a predictive model to prioritise a range of exotic diseases. The best validation of producers' estimates was achieved using a model derived from all responses. The highest weighted criteria were attack rate, case fatality rate and market loss, and the highest priority diseases were the vesicular diseases followed by swine fevers and zoonotic encephalitides. Comparison of results with a previous study in which probabilistic inversion was used to prioritise diseases for the same group of producers highlighted differences between disease prioritisation methods. Overall, this study demonstrated that POTCal can be used for disease prioritisation. An advantage of POTCal is that valid models can be developed that reflect decision-makers' heuristics. Specifically, this evaluation of the use of POTCal in animal health illustrates how the judgements of participants can be incorporated into a decision-making process. Further research is needed to investigate the influence of scenarios presented to participants during POTCal evaluations, and the robustness of this approach applied to different disease issues (e.g. exotic versus endemic) and production types (e.g. intensive versus extensive). To our knowledge, this is the first report of the use of POTCal for disease prioritisation.

Roaming behaviour of dogs in four remote Aboriginal communities in the Northern Territory, Australia: preliminary investigations

OBJECTIVE

To estimate the home range (HR) and investigate the potential predictors for roaming of 58 dogs in four Aboriginal communities in the Northern Territory.

DESIGN

Prospective study.

PROCEDURE

Global positioning system (GPS) collars were attached to the dogs for 1-4 days, recording location fixes every 1-3 min. Utilisation distributions (UDs) and extended (95% isopleth) and core (50% isopleth) HRs of dogs were determined. Potential predictors of roaming were assessed.

RESULTS

Estimated core (median, 0.27 ha) and extended (median, 3.1 ha) HRs differed significantly (P = 0.0225 and 0.0345, respectively) between the four communities; dogs in the coastal community travelled significantly (P < 0.0001) more per day than dogs in the three inland communities studied. Significant associations were found between extended HR size and sex (P = 0.0050) and sex + neuter (P = 0.0218), and between core HR size and sex (P = 0.0010), neuter status (P = 0.0255) and sex + neuter (P = 0.0025). Entire males roamed more than neutered females. The core HR of dogs with poor/fair body condition scores (BCSs) was larger than dogs with ideal/obese BCSs (P = 0.0394). Neutered male dogs also travelled more per day than entire female dogs (P = 0.0475).

CONCLUSIONS

Roaming information can be used to inform the management of dogs in remote communities and to design disease control programs. Widespread data collection across the Northern Territory should be undertaken to further investigate the associations found in this study, considering that data were collected during relatively short periods of time in one season.

Pre- and post-weaning scours in southeastern Australia: A survey of 22 commercial pig herds and characterisation of Escherichia coli isolates

Diarrhoeal diseases in piglets caused by Escherichia coli are responsible for substantial losses each year in the Australian pig industry. A cross-sectional survey was conducted (September 2013–May 2014) across 22 commercial pig herds located in southeastern Australia: NSW (n = 9); VIC (n = 10); and SA (n = 3), to estimate the prevalence of E. coli associated diarrhoea in pre- and post-weaned piglets and to identify key risk factors associated with E. coli disease. A questionnaire on management and husbandry practices was included. Faecal samples (n = 50 from each herd) were tested for the presence of β-haemolytic E. coli. Species level identification was confirmed by matrix-assisted laser desorption / ionisation time-of-flight mass spectrometry (MALDI-TOF/MS). ETEC virulence and enterotoxin genes (F4, F5, F6, F18, F41, STa, STb and LT) were screened for by multiplex PCR. This study assessed 60 potential risk factors for E. coli disease in post-weaned piglets, with 2 key factors–recent disease events and the presence of bedding, statistically associated with the presence of post-weaning scours. The prevalence of diarrhea in pre-weaned pens was 17% (16/93), compared with 24% (24/102) in post-weaned pens. The most prevalent β-haemolytic ETEC genes were F18 (32%) and STb (32%) but isolates were more likely to contain F4:STb (11 of 22 herds, 23%), than F18:STb (5 of 22 herds, 6%). These findings indicate that recent disease events that have occurred within the last 12 months, and by the use of bedding or not maintaining fresh bedding can have significant impacts on piglet diarrhoea.

Comparative genomics of Enterococcus spp. isolated from bovine feces

Background

Enterococcus is ubiquitous in nature and is a commensal of both the bovine and human gastrointestinal (GI) tract. It is also associated with clinical infections in humans. Subtherapeutic administration of antibiotics to cattle selects for antibiotic resistant enterococci in the bovine GI tract. Antibiotic resistance genes (ARGs) may be present in enterococci following antibiotic use in cattle. If located on mobile genetic elements (MGEs) their dissemination between Enterococcus species and to pathogenic bacteria may be promoted, reducing the efficacy of antibiotics.

Results

We present a comparative genomic analysis of twenty-one Enterococcus spp. isolated from bovine feces including Enterococcus hirae (n = 10), Enterococcus faecium (n = 3), Enterococcus villorum (n = 2), Enterococcus casseliflavus (n = 2), Enterococcus faecalis (n = 1), Enterococcus durans (n = 1), Enterococcus gallinarum (n = 1) and Enterococcus thailandicus (n = 1). The analysis revealed E. faecium and E. faecalis from bovine feces share features with human clinical isolates, including virulence factors. The Tn917 transposon conferring macrolide-lincosamide-streptogramin B resistance was identified in both E. faecium and E. hirae, suggesting dissemination of ARGs on MGEs may occur in the bovine GI tract. An E. faecium isolate was also identified with two integrative conjugative elements (ICEs) belonging to the Tn916 family of ICE, Tn916 and Tn5801, both conferring tetracycline resistance.

Conclusions

This study confirms the presence of enterococci in the bovine GI tract possessing ARGs on MGEs, but the predominant species in cattle, E. hirae is not commonly associated with infections in humans. Analysis using additional complete genomes of E. faecium from the NCBI database demonstrated differential clustering of commensal and clinical isolates, suggesting that these strains may be specifically adapted to their respective environments.

Electronic supplementary material

The online version of this article (doi:10.1186/s12866-017-0962-1) contains supplementary material, which is available to authorized users.

Qualitative Research to Design Sustainable Community-Based Surveillance for Rabies in Northern Australia and Papua New Guinea

Given the proximity and recent spread of rabies in Indonesia, effective rabies surveillance in dogs is a priority in Northern Australia and Papua New Guinea (PNG). Reporting of potential cases requires community engagement; therefore, the value and acceptability of such a system is critical to ensure sustainable surveillance. We used qualitative research methods to identify factors that influence the acceptability and value of community-based rabies surveillance. Thirty-two semi-structured interviews were conducted with informants in 16 communities in East Arnhem, the Northern Peninsula Area, the Torres Strait in Australia, and in Western Province, PNG. Thematic analysis identified common themes including the importance of verbal communication, particularly via radio, community meetings, and direct conversation. We also found that dogs have high value to community members through connection to culture, economic (especially hunting), and companionship. The greatest barrier to the reporting of sick dogs was insufficient veterinary services and the subsequent lack of treatment response. In some regions, acceptance that sick dogs are a normal daily occurrence and lack of trust of authorities were also barriers to reporting. The findings from this study will be used to design sustainable rabies surveillance in Northern Australia and PNG by utilizing traditional communication channels and building on existing and valued animal-management services. The methods and findings of this study complement previous quantitative research, so as to target surveillance to high-risk areas within these regions.

Epidemiology and clinical presentation of canine distemper disease in dogs and ferrets in Australia, 2006-2014

OBJECTIVE

To determine the status and distribution of distemper in Australian dogs and ferrets.

DESIGN

Retrospective case series.

METHODS

Cases were identified via a national voluntary disease reporting system, veterinarian groups and a national laboratory database. The geographic distribution, seasonal distribution, signalment and clinical presentation of cases were described using maps and frequency distributions.

RESULTS

A total of 48 individually affected dogs and ferrets in 27 case groups were identified, including eight confirmed case groups (> one individual). Confirmed cases were more common in summer and on the central coast of New South Wales and southern Victoria, and occurred exclusively in young, unvaccinated dogs. For dogs there was no obvious sex predilection. A mortality rate of 100% in ferrets and up to 77% in dogs was estimated. Neurological, gastrointestinal and respiratory were the most commonly reported systems affected in dogs and ferrets. There was no evidence that any large, unreported outbreaks occurred during the study period.

CONCLUSIONS

Continuation of vaccination against canine distemper virus is justified within Australia, particularly for younger dogs. Veterinarians should continue to consider distemper in their differential diagnosis of cases with neurological, gastrointestinal and respiratory presentation.

Peste des Petits Ruminants risk factors and space-time clusters in Mymensingh, Bangladesh

Using a hospital-based case-control study design, our aim was to identify risk factors for-and space-time clusters of-Peste des Petits Ruminants (PPR) in Mymensingh, Bangladesh. Three hundred and eighty PPR cases diagnosed between January 2005 and December 2014 at the Bangladesh Agricultural University Veterinary Teaching Hospital (BAUVTH) were selected; three controls per case from BAUVTH were then selected (n = 1,048). From records, data extracted included information on date of report, location, age, breed, sex and body weight of goats. A mixed multivariable logistic regression model was built to identify risk factors. Location was included as a random effect and season and demographic variables as fixed effects. The approximate geographic coordinates of locations were collected, and the scan statistic (Bernoulli model) was used to identify space-time clusters of PPR. Compared with goats <4 months of age, the odds of PPR were 3 (95% confidence interval [CI]: 1.95-4.66), 1.9 (CI: 1.34-2.76) and 1.8 times (95% CI: 1.19-2.58) greater in goats aged 4-6, >6-12 and >12-24 months, respectively. The occurrence of PPR was also significantly higher (odds ratio [OR] 3.2; 95% CI: 1.15-8.59) in the Jamunapari breed than Black Bengals. Significantly higher odds of PPR were observed in winter (OR 1.6; 95% CI: 1.06-2.14) and the monsoon season (OR 1.5; 95% CI: 1.04-2.11) compared with the post-monsoon season. Two significant (p < .05) space-time clusters were identified between 2 December 2006 and 6 September 2007 (two locations) and 28 November 2006 and 13 February 2007 (five locations). Peste des Petits Ruminants is endemic in Bangladesh, but also occurs as discrete outbreaks. Control efforts-such as vaccination-should focus on high-risk groups (4-24 months of age, Jamunapari breed), prior to the onset of winter and the monsoon season so as to increase immunity during high-risk periods, and focus on disease hotspots.

Ensemble modelling and structured decision-making to support Emergency Disease Management

Epidemiological models in animal health are commonly used as decision-support tools to understand the impact of various control actions on infection spread in susceptible populations. Different models contain different assumptions and parameterizations, and policy decisions might be improved by considering outputs from multiple models. However, a transparent decision-support framework to integrate outputs from multiple models is nascent in epidemiology. Ensemble modelling and structured decision-making integrate the outputs of multiple models, compare policy actions and support policy decision-making. We briefly review the epidemiological application of ensemble modelling and structured decision-making and illustrate the potential of these methods using foot and mouth disease (FMD) models. In case study one, we apply structured decision-making to compare five possible control actions across three FMD models and show which control actions and outbreak costs are robustly supported and which are impacted by model uncertainty. In case study two, we develop a methodology for weighting the outputs of different models and show how different weighting schemes may impact the choice of control action. Using these case studies, we broadly illustrate the potential of ensemble modelling and structured decision-making in epidemiology to provide better information for decision-making and outline necessary development of these methods for their further application.

Brucella abortus is Prevalent in Both Humans and Animals in Bangladesh

To determine the role of different Brucella (B.) spp. in Bangladesh, 62 animal samples and 500 human sera were tested. Animal samples from cattle, goats and sheep (including milk, bull semen, vaginal swabs and placentas) were cultured for Brucella spp. Three test-positive human sera and all animal samples were screened by Brucella genus-specific real-time PCR (RT-PCR), and positive samples were then tested by IS711 RT-PCR to detect B. abortus and B. melitensis DNA. Only B. abortus DNA was amplified from 13 human and six animal samples. This is the first report describing B. abortus as the aetiological agent of brucellosis in occupationally exposed humans in Bangladesh. Of note is failure to detect B. melitensis DNA, the species most often associated with human brucellosis worldwide. Further studies are required to explore the occurrence of Brucella melitensis in Bangladesh.

Predicted Spatial Spread of Canine Rabies in Australia

Modelling disease dynamics is most useful when data are limited. We present a spatial transmission model for the spread of canine rabies in the currently rabies-free wild dog population of Australia. The introduction of a sub-clinically infected dog from Indonesia is a distinct possibility, as is the spillover infection of wild dogs. Ranges for parameters were estimated from the literature and expert opinion, or set to span an order of magnitude. Rabies was judged to have spread spatially if a new infectious case appeared 120 km from the index case. We found 21% of initial value settings resulted in canine rabies spreading 120km, and on doing so at a median speed of 67 km/year. Parameters governing dog movements and behaviour, around which there is a paucity of knowledge, explained most of the variance in model outcomes. Dog density, especially when interactions with other parameters were included, explained some of the variance in whether rabies spread 120km, but dog demography (mean lifespan and mean replacement period) had minimal impact. These results provide a clear research direction if Australia is to improve its preparedness for rabies.

Do songbirds attend to song categories when selecting breeding habitat? A case study with a wood warbler

Breeding habitat selection strongly affects reproduction and individual fitness. Among birds, using social cues from conspecifics to select habitat is widespread, but how different types of conspecific social cues influence breeding habitat selection remains less understood. We conducted a playback experiment evaluating if the yellow warbler (Setophaga petechia), a species with two song categories linked to pairing status, uses categories differently when selecting breeding habitat. We hypothesized that yellow warblers use second-category singing mode, which is mostly sung by paired males, over first-category singing mode for habitat selection, as successfully paired males should indicate higher-quality habitat. We broadcast yellow warbler first-category singing mode, second-category singing mode, and silent controls at sites in Illinois. Yellow warblers were more abundant at sites treated with second-category singing mode compared other sites. Our results demonstrate that yellow warblers use social cues informing successful pairing over other types of social cues to select breeding habitat.

Methods and Processes of Developing the Strengthening the Reporting of Observational Studies in Epidemiology-Veterinary (STROBE-Vet) Statement

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.

Explanation and Elaboration Document for the STROBE-Vet Statement: Strengthening the Reporting of Observational Studies in Epidemiology-Veterinary Extension

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_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.

Methods and Processes of Developing the Strengthening the Reporting of Observational Studies in Epidemiology - Veterinary (STROBE-Vet) Statement

Background

Reporting of observational studies in veterinary research presents challenges that often are not addressed in published reporting guidelines.

Objective

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.

Design

Consensus meeting of experts.

Setting

Mississauga, Canada.

Participants

Seventeen experts from North America, Europe, and Australia.

Methods

Experts completed a pre‐meeting 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.

Results

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/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).

Conclusion

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.

Expert Opinion to Identify High-Risk Entry Routes of Canine Rabies into Papua New Guinea

The proximity of Papua New Guinea (PNG) to canine rabies-endemic countries in South-East Asia presents a risk of incursion of this disease into PNG and the rest of the Oceanic region. The objective of this study was to identify the highest risk routes for entry of dogs - associated with movement of people - into PNG from canine rabies-endemic countries. A structured, in-country expert-elicitation workshop was used, and 20 entry routes were identified. The highest risk routes were three land routes from Papua, Indonesia (hunters, traditional border crossers and unregulated, unchecked 'shopper-crossers') and two sea routes (fishing and logging). These results will be used to direct more detailed risk assessments to develop surveillance strategies and incursion response plans.

Evaluation of a PCR to Detect Salmonella in Fecal Samples of Horses Admitted to a Veterinary Teaching Hospital

The diagnostic accuracy of a PCR used to identify horses shedding Salmonella spp. in their feces during hospitalization was estimated, relative to bacterial culture of serially collected fecal samples, using longitudinal data. Five or more fecal samples were collected from each of 116 horses admitted as inpatients, for reasons other than gastrointestinal disease, between July 26, 2001 and October 25, 2002. All 873 fecal samples collected were tested with a PCR based on oligonucleotide primers defining a highly conserved segment of the histidine transport operon gene of Salmonella typhimurium, and each sample was cultured for Salmonella spp. One or more samples from 87 (75%) horses were PCR positive, and Salmonella was cultured from 1 or more samples from 11 (9.5%) horses. All culture-positive horses had at least 1 PCR-positive result, whereas only 29 (28%) culture-negative horses were PCR negative on all fecal samples tested. The PCR was most specific, relative to bacterial culture of serially collected fecal samples, when used to test samples from Quarterhorse or breeds other than Thoroughbred or Standardbred, or from clinical (vs. healthy, accompanying horses) cases. Overall, the PCR had the greatest agreement (70%), compared with bacterial culture of serially collected fecal samples, using a cutoff of 2 or more positive PCR test results to define a Salmonella-positive horse. The reasons why some fecal samples, from which Salmonella organisms cannot be isolated, are PCR positive need to be determined before the PCR can be incorporated into Salmonella surveillance programs for hospitalized equine populations.

Development and evaluation of real-time PCR assays for bloodmeal identification in Culicoides midges

Culicoides (Diptera: Ceratopogonidae) midges are the biological vectors of a number of arboviruses of veterinary importance. However, knowledge relating to the basic biology of some species, including their host-feeding preferences, is limited. Identification of host-feeding preferences in haematophagous insects can help to elucidate the transmission dynamics of the arboviruses they may transmit. In this study, a series of semi-quantitative real-time polymerase chain reaction (qPCR) assays to identify the vertebrate host sources of bloodmeals of Culicoides midges was developed. Two pan-reactive species group and seven species-specific qPCR assays were developed and evaluated. The assays are quick to perform and less expensive than nucleic acid sequencing of bloodmeals. Using these assays, it was possible to rapidly test nearly 700 blood-fed midges of various species from several geographic locations in Australia.

A Survey of Dog Owners in Remote Northern Australian Indigenous Communities to Inform Rabies Incursion Planning

Australia is underprepared for a rabies incursion due to a lack of information about how a rabies outbreak would spread within the susceptible canine populations and which control strategies would be best to control it. The aim of this study was to collect information to parameterize a recently developed dog rabies spread model as well as use this information to gauge how the community would accept potential control strategies. Such information-together with model outputs-would be used to inform decision makers on the best control strategies and improve Australia's preparedness against a canine rabies incursion. The parameters this study focussed on were detection time, vaccination rates and dog-culling and dog movement restriction compliance. A cross-sectional survey of 31 dog-owners, using a questionnaire, was undertaken in the five communities of the Northern Peninsular Area (NPA) in northern Australia regarding community dog movements, veterinary visits, reporting systems, perceptions of sick dogs and potential human behaviours during hypothetical rabies outbreaks. It highlighted the significant shortfalls in veterinary care that would need to be vastly improved during an outbreak, who educational programs should be targeted towards and which dog movements should be restricted. The results indicate that men were significantly more likely than women to allow their dogs to roam and to move their dogs. The current low vaccination rate of 12% highlighted the limited veterinary services that would need to be substantially increased to achieve effective rabies control. Participation in mass vaccination was accepted by 100% of the respondents. There was lower acceptance for other possible rabies control strategies with 10-20% of the respondents stating a resistance to both a mass culling program and a ban on dog movements. Consequently, movement bans and mass dog culling would have limited effectiveness as a control strategy in the NPA community. More than half of the respondents said that they would report their sick dogs within a week. This would lead to a much more optimistic rabies detection time than observed in other regions with recent dog rabies outbreaks. Findings from this study can be used to parameterize a recently developed dog rabies spread model as well as to develop informed policies for managing a future rabies incursion, thus improving Australia's preparedness against a canine rabies incursion.

Do seasonal patterns of rat snake (Pantherophis obsoletus) and black racer (Coluber constrictor) activity predict avian nest predation?

Avian nest success often varies seasonally and because predation is the primary cause of nest failure, seasonal variation in predator activity has been hypothesized to explain seasonal variation in nest success. Despite the fact that nest predator communities are often diverse, recent evidence from studies of snakes that are nest predators has lent some support to the link between snake activity and nest predation. However, the strength of the relationship has varied among studies. Explaining this variation is difficult, because none of these studies directly identified nest predators, the link between predator activity and nest survival was inferred. To address this knowledge gap, we examined seasonal variation in daily survival rates of 463 bird nests (of 17 bird species) and used cameras to document predator identity at 137 nests. We simultaneously quantified seasonal activity patterns of two local snake species (N = 30 individuals) using manual (2136 snake locations) and automated (89,165 movements detected) radiotelemetry. Rat snakes (Pantherophis obsoletus), the dominant snake predator at the site (~28% of observed nest predations), were most active in late May and early June, a pattern reported elsewhere for this species. When analyzing all monitored nests, we found no link between nest predation and seasonal activity of rat snakes. When analyzing only nests with known predator identities (filmed nests), however, we found that rat snakes were more likely to prey on nests during periods when they were moving the greatest distances. Similarly, analyses of all monitored nests indicated that nest survival was not linked to racer activity patterns, but racer-specific predation (N = 17 nests) of filmed nests was higher when racers were moving the greatest distances. Our results suggest that the activity of predators may be associated with higher predation rates by those predators, but that those effects can be difficult to detect when nest predator communities are diverse and predator identities are not known. Additionally, our results suggest that hand-tracking of snakes provides a reliable indicator of predator activity that may be more indicative of foraging behavior than movement frequency provided by automated telemetry systems.

Monitoring schistosomiasis risk in East China over space and time using a Bayesian hierarchical modeling approach

Schistosomiasis remains a major public health problem and causes substantial economic impact in east China, particularly along the Yangtze River Basin. Disease forecasting and surveillance can assist in the development and implementation of more effective intervention measures to control disease. In this study, we applied a Bayesian hierarchical spatio-temporal model to describe trends in schistosomiasis risk in Anhui Province, China, using annual parasitological and environmental data for the period 1997–2010. A computationally efficient approach–Integrated Nested Laplace Approximation–was used for model inference. A zero-inflated, negative binomial model best described the spatio-temporal dynamics of schistosomiasis risk. It predicted that the disease risk would generally be low and stable except for some specific, local areas during the period 2011–2014. High-risk counties were identified in the forecasting maps: three in which the risk remained high, and two in which risk would become high. The results indicated that schistosomiasis risk has been reduced to consistently low levels throughout much of this region of China; however, some counties were identified in which progress in schistosomiasis control was less than satisfactory. Whilst maintaining overall control, specific interventions in the future should focus on these refractive counties as part of a strategy to eliminate schistosomiasis from this region.

Live pig markets in eastern Indonesia: Trader characteristics, biosecurity and implications for disease spread

Classical swine fever has been negatively impacting pig production in Nusa Tenggara Timur province in eastern Indonesia since its introduction in the 1990s, with live market trade contributing to disease spread. To understand market trader knowledge and practices regarding pig management, biosecurity, pig movements and pig health (specifically CSF), a repeated survey was conducted with pig sellers and pig buyers at 9 market sites across West Timor and the islands of Flores and Sumba. A total of 292 sellers and 281 buyers were interviewed in 2009 during two periods (rounds), a high-demand month (September) and a low-demand month (November). Information was collected via questionnaire. The majority of traders were male (sellers: 89%; buyers: 87%) with the highest level of completed education being primary school (sellers: 48%; buyers: 41%). The primary occupation of most respondents was farming: 90% of sellers and 87% of buyers were smallholder pig farmers and tended to sell their own home-raised pigs at market (52%). Pigs were sold for monetary gain either for primary (52%) or extra income (44%). Markets tended to be selected based on a good reputation (62%), a location close to residence (62%) and having the desired pig type (59%). Pig sales through markets were reported to be highest from August to October with 31% of sellers trading pigs at two or more markets. Prices at market were significantly higher on Sumba compared to West Timor and cross-bred pigs were significantly more expensive than indigenous pigs. Understanding of CSF and biosecurity was limited: 85% of sellers and 83% of buyers had no prior knowledge of CSF. Fifty-four percent of sellers reported no use of any biosecurity practices at market. Most respondents (88%) were able to recognise at least one clinical sign of a sick pig. Informal pig movements were also identified: 18% of pig buyers purchased pigs directly from other farmers. This study has provided baseline information on market trader activities at live pig markets in NTT that can contribute to the formation of sustainable strategies for improving pig health. Since NTT is the poorest province in Indonesia and pigs play a vital socioeconomic role in this province, market management and farmer education is needed to improve the pig market chain and contribute to socioeconomic development.

Seroprevalence of feline immunodeficiency virus and feline leukaemia virus in Australia: risk factors for infection and geographical influences (2011-2013)

OBJECTIVES

Our aim was to: (i) determine the current seroprevalence of feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV) in three large cohorts of cats from Australia; and (ii) investigate potential risk factors for retroviral infection.

METHODS

Cohort 1 (n = 2151 for FIV, n = 2241 for FeLV) consisted of cats surrendered to a shelter on the west coast of Australia (Perth, Western Australia [WA]). Cohort 2 (n = 2083 for FIV, n = 2032 for FeLV) consisted of client-owned cats with outdoor access recruited from around Australia through participating veterinary clinics. Cohort 3 (n = 169 for FIV, n = 166 for FeLV) consisted of cats presenting to Murdoch University Veterinary Hospital for a variety of reasons. Fresh whole blood was collected and tested using a commercially available point-of-care lateral flow ELISA kit that detects p27 FeLV antigen and antibodies to FIV antigens (p15 and p24) (cohorts 1 and 2), or one of two lateral flow immunochromatography kits that detect p27 antigen and antibodies to FIV antigen (p24 and/or gp40) (cohort 3). Data recorded for cats in cohort 2 included signalment, presenting complaint and postcode, allowing investigation of risk factors for FIV or FeLV infection, as well as potential geographical 'hot spots' for infection.

RESULTS

The seroprevalence of FIV was 6% (cohort 1), 15% (cohort 2) and 14% (cohort 3), while the seroprevalence of FeLV was 1%, 2% and 4% in the same respective cohorts. Risk factors for FIV infection among cats in cohort 2 included age (>3 years), sex (male), neutering status (entire males) and location (WA had a significantly higher FIV seroprevalence compared with the Australian Capital Territory, New South Wales and Victoria). Risk factors for FeLV infection among cats in cohort 2 included health status ('sick') and location (WA cats were approximately three times more likely to be FeLV-infected compared with the rest of Australia). No geographical hot spots of FIV infection were identified.

CONCLUSIONS AND RELEVANCE

Both FIV and FeLV remain important infections among Australian cats. WA has a higher seroprevalence of both feline retroviruses compared with the rest of Australia, which has been noted in previous studies. A lower neutering rate for client-owned male cats is likely responsible for the higher seroprevalence of FIV infection in WA cats, while the reason for the higher seroprevalence of FeLV in WA cats is currently unknown.