Introduction of African swine fever (ASF) to China in mid-2018 and the subsequent transboundary spread across Asia devastated regional swine production, affecting live pig and pork product-related markets worldwide. To explore the spatiotemporal spread of ASF in China, we reconstructed possible ASF transmission networks using nearest neighbour, exponential function, equal probability, and spatiotemporal case-distribution algorithms. From these networks, we estimated the reproduction numbers, serial intervals, and transmission distances of the outbreak. The mean serial interval between paired units was around 29 days for all algorithms, while the mean transmission distance ranged 332 –456 km. The reproduction numbers for each algorithm peaked during the first two weeks and steadily declined through the end of 2018 before hovering around the epidemic threshold value of 1 with sporadic increases during 2019. These results suggest that 1) swine husbandry practices and production systems that lend themselves to long-range transmission drove ASF spread; 2) outbreaks went undetected by the surveillance system. Efforts by China and other affected countries to control ASF within their jurisdictions may be aided by the reconstructed spatiotemporal model. Continued support for strict implementation of biosecurity standards and improvements to ASF surveillance is essential for halting transmission in China and spread across Asia.

Dromedary camels have been shown to be the main reservoir for human Middle East respiratory syndrome (MERS) infections. This systematic review aims to compile and analyse all published data on MERS-coronavirus (CoV) in the global camel population to provide an overview of current knowledge on the distribution, spread and risk factors of infections in dromedary camels. We included original research articles containing laboratory evidence of MERS-CoV infections in dromedary camels in the field from 2013 to April 2018. In general, camels only show minor clinical signs of disease after being infected with MERS-CoV. Serological evidence of MERS-CoV in camels has been found in 20 countries, with molecular evidence for virus circulation in 13 countries. The seroprevalence of MERS-CoV antibodies increases with age in camels, while the prevalence of viral shedding as determined by MERS-CoV RNA detection in nasal swabs decreases. In several studies, camels that were sampled at animal markets or quarantine facilities were seropositive more often than camels at farms as well as imported camels vs. locally bred camels. Some studies show a relatively higher seroprevalence and viral detection during the cooler winter months. Knowledge of the animal reservoir of MERS-CoV is essential to develop intervention and control measures to prevent human infections.

We evaluated the performance of three serological tests – an immunoglobulin G indirect enzyme linked immunosorbent assay (iELISA), a Rose Bengal test and a slow agglutination test (SAT) – for the diagnosis of bovine brucellosis in Bangladesh. Cattle sera (n = 1360) sourced from Mymensingh district (MD) and a Government owned dairy farm (GF) were tested in parallel. We used a Bayesian latent class model that adjusted for the conditional dependence among the three tests and assumed constant diagnostic accuracy of the three tests in both populations. The sensitivity and specificity of the three tests varied from 84.6% to 93.7%, respectively. The true prevalences of bovine brucellosis in MD and the GF were 0.6% and 20.4%, respectively. Parallel interpretation of iELISA and SAT yielded the highest negative predictive values: 99.9% in MD and 99.6% in the GF; whereas serial interpretation of both iELISA and SAT produced the highest positive predictive value (PPV): 99.9% in the GF and also high PPV (98.9%) in MD. We recommend the use of both iELISA and SAT together and serial interpretation for culling and parallel interpretation for import decisions. Removal of brucellosis positive cattle will contribute to the control of brucellosis as a public health risk in Bangladesh.

Understanding infection dynamics in animal hosts is fundamental to managing spillover and emergence of zoonotic infections. Hendra virus is endemic in Australian pteropodid bat populations and can be lethal to horses and humans. However, we know little about the factors driving Hendra virus prevalence in resevoir bat populations, making spillover difficult to predict. We use Hendra virus prevalence data collected from 13 000 pooled bat urine samples across space and time to determine if pulses of prevalence are periodic and synchronized across sites. We also test whether site-specific precipitation and temperature affect the amplitude of the largest annual prevalence pulses. We found little evidence for a periodic signal in Hendra virus prevalence. Although the largest amplitude pulses tended to occur over winter, pulses could also occur in other seasons. We found that Hendra virus prevalence was weakly synchronized across sites over short distances, suggesting that prevalence is driven by local-scale effects. Finally, we found that drier conditions in previous seasons and the abundance of Pteropus alecto were positively correlated with the peak annual values of Hendra virus prevalence. Our results suggest that in addition to seasonal effects, bat density and local climatic conditions interact to drive Hendra virus infection dynamics.

Syndromic surveillance (SyS) systems currently exploit various sources of health-related data, most of which are collected for purposes other than surveillance (e.g. economic). Several European SyS systems use data collected during meat inspection for syndromic surveillance of animal health, as some diseases may be more easily detected post-mortem than at their point of origin or during the ante-mortem inspection upon arrival at the slaughterhouse. In this paper we use simulation to evaluate the performance of a quasi-Poisson regression (also known as an improved Farrington) algorithm for the detection of disease outbreaks during post-mortem inspection of slaughtered animals. When parameterizing the algorithm based on the retrospective analyses of 6 years of historic data, the probability of detection was satisfactory for large (range 83–445 cases) outbreaks but poor for small (range 20–177 cases) outbreaks. Varying the amount of historical data used to fit the algorithm can help increasing the probability of detection for small outbreaks. However, while the use of a 0·975 quantile generated a low false-positive rate, in most cases, more than 50% of outbreak cases had already occurred at the time of detection. High variance observed in the whole carcass condemnations time-series, and lack of flexibility in terms of the temporal distribution of simulated outbreaks resulting from low reporting frequency (monthly), constitute major challenges for early detection of outbreaks in the livestock population based on meat inspection data. Reporting frequency should be increased in the future to improve timeliness of the SyS system while increased sensitivity may be achieved by integrating meat inspection data into a multivariate system simultaneously evaluating multiple sources of data on livestock health.

A number of recent reports emphasize the risk of zoonotic diseases and the high degree of prevalence of asymptomatic animals infected with Leptospira interrogans. This report sought to assess the prevalence of antibodies to certain serovars of L. interrogans, and to describe the association between seropositivity and risk factors associated with within-flock transmission in a mountainous region of Mexico. Overall seroprevalence to L. interrogans was 54·5% (95% confidence interval 48·3–60·7); the most frequent serovar was Icterohaemorrhagiae. The accumulation of placentas and fetuses at a site close to lambing paddocks can play a significant role as a risk factor for within-flock transmission of L. interrogans in transhumant farming systems in the municipality of Xalatlaco. The high prevalence of L. interrogans antibodies supports the hypothesis that natural foci of this zoonosis are present in sheep flocks in this area. These findings emphasize the need for planning and implementation of control programmes for ovine leptospirosis in Mexico and elsewhere.

The bacterium Francisella tularensis causes the vector-borne zoonotic disease tularemia, and may infect a wide range of hosts including invertebrates, mammals and birds. Transmission to humans occurs through contact with infected animals or contaminated environments, or through arthropod vectors. Tularemia has a broad geographical distribution, and there is evidence which suggests local emergence or re-emergence of this disease in Europe. This review was developed to provide an update on the geographical distribution of F. tularensis in humans, wildlife, domestic animals and vector species, to identify potential public health hazards, and to characterize the epidemiology of tularemia in Europe. Information was collated on cases in humans, domestic animals and wildlife, and on reports of detection of the bacterium in arthropod vectors, from 38 European countries for the period 1992–2012. Multiple international databases on human and animal health were consulted, as well as published reports in the literature. Tularemia is a disease of complex epidemiology that is challenging to understand and therefore to control. Many aspects of this disease remain poorly understood. Better understanding is needed of the epidemiological role of animal hosts, potential vectors, mechanisms of maintenance in the different ecosystems, and routes of transmission of the disease.

This study investigated the molecular prevalence of Trypanosoma lewisi and T. evansi in wild rodents from Cambodia, Lao PDR and Thailand. Between 2008 and 2012, rodents (and shrews) were trapped in nine locations and 616 of these were tested using three sets of primers: TRYP1 (amplifying ITS1 of ribosomal DNA of all trypanosomes), TBR (amplifying satellite genomic DNA of Trypanozoon parasites) and LEW1 (amplifying ITS1 of ribosomal DNA of T. lewisi). Based on the size of the PCR products using TRYP1, 17% were positive for T. lewisi and 1·0% positive for Trypanozoon. Results were confirmed by sequencing PCR products and by using more specific primers (LEW1 and TBR). The specificity of TRYP1 primers, however, failed as rodent DNA was amplified in some instances, giving unexpected product sizes. Using LEW1 primers, 13·3% of the samples were confirmed positive for T. lewisi, both by PCR and sequencing. In Thailand, T. lewisi was found in Rattus tanezumi, R. exulans and Berylmys; in Lao PDR, in R. tanezumi and R. exulans, and in Cambodia in R. tanezumi, R. exulans and R. norvegicus. Using TBR, 1·3% of the samples tested positive for Trypanozoon by PCR and sequencing; T. evansi is the only species of the Trypanozoon subgenus possibly present in wild Asian rodents. These results confirmed its presence in rodents from Thailand (R. tanezumi), Lao PDR (R. tanezumi, R. nitidus) and Cambodia (R. tanezumi, Niviventer fulvescens, Maxomys surifer). Based on the information related to rodent trapping, it was found that rodent species trapped in and around human dwellings had a higher prevalence of T. lewisi infection. R. tanezumi and R. exulans, two synanthropic species, were mainly found infected in this habitat suggesting a role as a reservoir and thus a potential source of T. lewisi for human infection.

A key element of national control programmes (NCPs) for Salmonella in commercial laying flocks, introduced across the European Union, is the identification of infected flocks and holdings through statutory sampling. It is therefore important to know the sensitivity of the sampling methods, in order to design effective and efficient surveillance for Salmonella. However, improved Salmonella control in response to the NCP may have influenced key factors that determine the sensitivity of the sampling methods used to detect Salmonella in NCPs. Therefore the aim of this study was to compare estimates of the sensitivity of the sampling methods using data collected before and after the introduction of the NCP, using Bayesian methods. There was a large reduction in the sensitivity of dust in non-cage flocks between the pre-NCP studies (81% of samples positive in positive flocks) and post-NCP studies (10% of samples positive in positive flocks), leading to the conclusion that sampling dust is not recommended for detection of Salmonella in non-cage flocks. However, cage dust (43% of samples positive in positive flocks) was found to be more sensitive than cage faeces (29% of samples positive in positive flocks). To have a high probability of detection, several NCP-style samples need to be used. For confirmation of Salmonella, five NCP faecal samples for cage flocks, and three NCP faecal boot swab samples for non-cage flocks would be required to have the equivalent sensitivity of the EU baseline survey method, which was estimated to have an 87% and 75% sensitivity to detect Salmonella at a 5% within-flock prevalence in cage and non-cage flocks, respectively.

A total of 207 wild rodents were caught on nine pig farms, five chicken farms and five non-farm locations in Sweden and surveyed for a selection of bacteria, parasites and viruses. Lawsonia intracellularia and pathogenic Yersinia enterocolitica were only detected in rodents on pig farms (9% and 8% prevalence, respectively) which indicate that these agents are more likely to be transmitted to rodents from pigs or the environment on infected farms. Brachyspira hyodysenteriae (1%), Brachyspira intermedia (2%), Campylobacter jejuni (4%), Campylobacter upsaliensis (2%), leptospires (7%) and encephalomyocarditis virus (9%) were also detected from rodents not in contact with farm animals. Giardia and Cryptosporidium spp. were common, although no zoonotic types were verified, and Salmonella enterica was isolated from 1/11 mice on one farm but not detected by PCR from any of the rodents. Trichinella spp. and Toxoplasma gondii were not detected.

Abortion and stillbirth are important reproductive disorders in the dairy industry and are often caused by infectious agents. This study investigated whether bovine viral diarrhoea virus (BVDV), Brucella spp., and Neospora caninum are associated with abortion and/or stillbirth in dairy cattle in Ethiopia. Dairy cattle from 99 farms were categorized as cases (n = 134) or controls (n = 268) according to reproductive data. Blood samples were screened for antibodies for these infectious agents. The overall proportion of cattle that were seropositive for BVDV, Brucella spp., and N. caninum was 11·7%, 3·2%, and 17·2%, respectively. Seropositivity for BVDV and Brucella spp. was similar for cases and controls, but significantly more cases were seropositive for N. caninum (29·8%) than controls (10·8%). This is the first report demonstrating N. caninum is common in dairy cattle in Ethiopia, and is probably a greater impediment to reproductive success in Ethiopian dairy farms than either BVDV or Brucella spp.

An outbreak of infective mastitis due to Enterococcus faecalis occurred in an intensive sheep farm in north Sardinia (Italy). E. faecalis, which is only rarely isolated from sheep milk, was unexpectedly found in 22·3% of positive samples at microbiological examination. Forty-five out of the 48 E. faecalis isolates showed the same multi-drug resistance pattern (cloxacillin, streptomycin, kanamycin, clindamycin, oxytetracycline). E. faecalis isolates were analysed by pulsed-field gel electrophoresis, and all 45 multi-drug resistant strains showed an indistinguishable macrorestiction profile, indicating their clonal origin. To our knowledge, this is the first report of an outbreak of mastitis in sheep caused by E. faecalis.

Due to its substantially lower prevalence of bovine tuberculosis (bTB) relative to other areas of Great Britain, Scotland was designated as an officially (bovine) TB-free region in 2009. This paper investigates resultant possibilities for reducing surveillance by developing risk-based alternatives to current 4-year testing of eligible herds. A model of freedom of infection was used to develop strategies that specifically tested herds that are at risk of infection but would probably not be identified by slaughterhouse meat inspection. The performance of current testing is mimicked by testing all herds that slaughter fewer than 25% of their total stock per year and regularly import animals from high-incidence areas of England and Wales or from Ireland. This system offers a cost reduction by requiring 25% fewer herd and animal tests and 25% fewer false positives.

Human brucellosis occurs when humans ingest or contact Brucella spp. from shedding animals or contaminated environments and food. In Georgia animal and human brucellosis is endemic, but the epidemiology has not been fully characterized. A case-control study was conducted in 2010 to identify risk factors for human brucellosis. Using multivariable logistic regression, the following risk factors were identified: animal-related work [odds ratio (OR) 77·8, 90% confidence interval (CI) 4·7–1278], non-animal-related work (OR 12·7, 90% CI 1·1–149), being unemployed or a pensioner (OR 13·1, 90% CI 1·7, 101), sheep ownership (OR 19·3, 90% CI 5·1–72·6), making dairy products (OR 12·4, 90% CI 1·4–113), living in eastern Georgia (Kakheti) (OR 278·1, 90% CI 9·5–8100), and being aged >44 years (OR 9·3, 90% CI 1·02–84·4). Education of at-risk groups about risk factors and control of disease in sheep may reduce the human disease risk. This is the first study of its kind in Georgia since the collapse of the Soviet Union.

Rabbit haemorrhagic disease is a major tool for the management of introduced, wild rabbits in Australia. However, new evidence suggests that rabbits may be developing resistance to the disease. Rabbits sourced from wild populations in central and southeastern Australia, and domestic rabbits for comparison, were experimentally challenged with a low 60 ID50 oral dose of commercially available Czech CAPM 351 virus – the original strain released in Australia. Levels of resistance to infection were generally higher than for unselected domestic rabbits and also differed (0–73% infection rates) between wild populations. Resistance was lower in populations from cooler, wetter regions and also low in arid regions with the highest resistance seen within zones of moderate rainfall. These findings suggest the external influences of non-pathogenic calicivirus in cooler, wetter areas and poor recruitment in arid populations may influence the development rate of resistance in Australia.

Disease surveillance programmes ought to be evaluated regularly to ensure they provide valuable information in an efficient manner. Evaluation of human and animal health surveillance programmes around the world is currently not standardized and therefore inconsistent. The aim of this systematic review was to review surveillance system attributes and the methods used for their assessment, together with the strengths and weaknesses of existing frameworks for evaluating surveillance in animal health, public health and allied disciplines. Information from 99 articles describing the evaluation of 101 surveillance systems was examined. A wide range of approaches for assessing 23 different system attributes was identified although most evaluations addressed only one or two attributes and comprehensive evaluations were uncommon. Surveillance objectives were often not stated in the articles reviewed and so the reasons for choosing certain attributes for assessment were not always apparent. This has the potential to introduce misleading results in surveillance evaluation. Due to the wide range of system attributes that may be assessed, methods should be explored which collapse these down into a small number of grouped characteristics by focusing on the relationships between attributes and their links to the objectives of the surveillance system and the evaluation. A generic and comprehensive evaluation framework could then be developed consisting of a limited number of common attributes together with several sets of secondary attributes which could be selected depending on the disease or range of diseases under surveillance and the purpose of the surveillance. Economic evaluation should be an integral part of the surveillance evaluation process. This would provide a significant benefit to decision-makers who often need to make choices based on limited or diminishing resources.

African horse sickness virus serotype 9 (AHSV-9) has been known for some time to be circulating amongst equids in West Africa without causing any clinical disease in indigenous horse populations. Whether this is due to local breeds of horses being resistant to disease or whether the AHSV-9 strains circulating are avirulent is currently unknown. This study shows that the majority (96%) of horses and donkeys sampled across The Gambia were seropositive for AHS, despite most being unvaccinated and having no previous history of showing clinical signs of AHS. Most young horses (<3 years) were seropositive with neutralizing antibodies specific to AHSV-9. Eight young equids (<3 years) were positive for AHSV-9 by serotype-specific RT–PCR and live AHSV-9 was isolated from two of these horses. Sequence analysis revealed the presence of an AHSV-9 strain showing 100% identity to Seg-2 of the AHSV-9 reference strain, indicating that the virus circulating in The Gambia was highly likely to have been derived from a live-attenuated AHSV-9 vaccine strain.

A meta-analysis was performed using all published and one unpublished long-term infection-challenge experiments to quantify the age- and dose-dependence of early and late shedding of Mycobacterium avium subsp. paratuberculosis (MAP) in cattle. There were 194 animals from 17 studies that fulfilled the inclusion criteria, of which 173 received a known dose of MAP and 21 were exposed naturally. Results from parametric time-to-event models indicated that challenging older calves or using multiple-exposure experimental systems resulted in a smaller proportion and shorter duration of early shedding as well as slower transition to late shedding from latent compartments. Calves exposed naturally showed variable infection progression rates, not dissimilar to other infection routes. The log-normal distribution was most appropriate for modelling infection-progression events. The infection pattern revealed by the modelling allowed better understanding of low-grade endemicity of MAP in cattle, and the parameter estimates are the basis for future transmission dynamics modelling.

Most lyssaviruses appear to have bat species as reservoir hosts. In Europe, of around 800 reported cases in bats, most were of European bat lyssavirus type 1 (EBLV-1) in Eptesicus serotinus (where the bat species was identified). About 20 cases of EBLV-2 were recorded, and these were in Myotis daubentonii and M. dasycneme. Through a passive surveillance scheme, Britain reports about one case a year of EBLV-2, but no cases of the more prevalent EBLV-1. An analysis of E. serotinus and M. daubentonii bat genetics in Britain reveals more structure in the former population than in the latter. Here we briefly review these differences, ask if this correlates with dispersal and movement patterns and use the results to suggest an hypothesis that EBLV-2 is more common than EBLV-1 in the UK, as genetic data suggest greater movement and regular immigration from Europe of M. daubentonii. We further suggest that this genetic approach is useful to anticipate the spread of exotic diseases in bats in any region of the world.

Bacterial biofilms are structured communities of bacterial cells enclosed in a self-produced polymer matrix that is attached to a surface. Biofilms protect and allow bacteria to survive and thrive in hostile environments. Bacteria within biofilms can withstand host immune responses, and are much less susceptible to antibiotics and disinfectants when compared with their planktonic counterparts. The ability to form biofilms is now considered a universal attribute of micro-organisms. Diseases associated with biofilms require novel methods for their prevention, diagnosis and treatment; this is largely due to the properties of biofilms. Surprisingly, biofilm formation by bacterial pathogens of veterinary importance has received relatively little attention. Here, we review the current knowledge of bacterial biofilms as well as studies performed on animal pathogens.