Co‐circulation of multiple genotypes of African swine fever viruses among domestic pigs in Zambia (2013–2015)

During 2013–2015, several and severe outbreaks of African swine fever (ASF ) affected domestic pigs in six provinces of Zambia. Genetic characterization of ASF viruses (ASFV s) using standardized genotyping procedures revealed that genotypes I, II and XIV were associated with these outbreaks. Molecular and epidemiological data suggest that genotype II ASFV (Georgia 2007/1‐like) detected in Northern Province of Zambia may have been introduced from neighbouring Tanzania. Also, a genotype II virus detected in Eastern Province of Zambia showed a p54 phylogenetic relationship that was inconsistent with that of p72, underscoring the genetic variability of ASFV s. While it appears genotype II viruses detected in Zambia arose from a domestic pig cycle, genotypes I and XIV possibly emerged from a sylvatic cycle. Overall, this study demonstrates the co‐circulation of multiple genotypes of ASFV s, involvement of both the sylvatic and domestic pig cycle in ASF outbreaks in Zambia and possible trans‐boundary spread of the disease in south‐eastern Africa. Indeed, while there is need for regional or international concerted efforts in the control of ASF , understanding pig marketing practices, pig population dynamics, pig housing and rearing systems and community engagement will be important considerations when designing future prevention and control strategies of this disease in Zambia.     

Neutralizing antibodies against Rift Valley fever virus in wild antelope in far northern KwaZulu‐Natal,South Africa,indicate recent virus circulation

Rift Valley fever (RVF) is a zoonotic viral disease of domestic ruminants in Africa and the Arabian Peninsula caused by a mosquito‐borne Phlebovirus. Outbreaks in livestock and humans occur after heavy rains favour breeding of vectors, and the virus is thought to survive dry seasons in the eggs of floodwater‐breeding aedine mosquitoes. We recently found high seroconversion rates to RVF virus (RVFV) in cattle and goats, in the absence of outbreaks, in far northern KwaZulu‐Natal (KZN), South Africa. Here, we report the prevalence of, and factors associated with, neutralizing antibodies to RVFV in 326 sera collected opportunistically from nyala (Tragelaphus angasii) and impala (Aepyceros melampus) culled during 2016–2018 in two nature reserves in the same area. The overall seroprevalence of RVFV, determined using the serum neutralization test, was 35.0% (114/326; 95%CI: 29.8%–40.4%) and tended to be higher in Ndumo Game Reserve (11/20; 55.0%; 95%CI: 31.5%–76.9%) than in Tembe Elephant Park (103/306; 33.6%; 95%CI: 28.4%–39.3%) (p = .087). The presence of antibodies in juveniles (6/21; 28.6%; 95%CI: 11.3%–52.2%) and sub‐adults (13/65; 20.0%; 95%CI: 11.1%–37.8%) confirmed that infections had occurred at least until 2016, well after the 2008–2011 RVF outbreaks in South Africa. Odds of seropositivity was higher in adults than in sub‐adults (OR = 3.98; 95%CI: 1.83–8.67; p = .001), in males than in females (OR = 2.66; 95%CI: 1.51–4.68; p = .001) and in animals collected ≤2 km from a swamp or floodplain compared with those collected further away (OR = 3.30; 95%CI: 1.70–6.38; p < .001). Under similar ecological conditions, domestic and wild ruminants may play a similar role in maintenance of RVFV circulation and either or both may serve as the mammalian host in a vector–host reservoir system. The study confirms the recent circulation of RVFV in the tropical coastal plain of northern KZN, providing the basis for investigation of factors affecting virus circulation and the role of wildlife in RVF epidemiology.     

The evolution of African swine fever virus in Sardinia (1978–2014) as revealed by whole‐genome sequencing and comparative analysis

African swine fever (ASF) is a highly contagious and lethal viral disease of pigs and wild boars, which is enzootic in many African countries and on the Italian island of Sardinia, where it has been present since 1978. Previous genetic analyses of Sardinian ASF virus (ASFV) isolates have revealed that they all belong to p72 genotype I, with only minor sequence variations. However, these studies examined only a few selected genes. To distinguish between these closely related isolates and better investigate ASFV evolution in Sardinia, we sequenced the complete genomes of 12 Sardinian ASFV isolates collected between 1978 and 2012, and compared them with 47/Ss/2008 and 26544/OG10. Most of the observed changes occurred in a time‐dependent manner; however, their biological significance remains unclear. As a whole, our results demonstrate the remarkable genetic stability of these strains, supporting a single‐source introduction of the virus.     

Attenuated and non‐haemadsorbing (non‐HAD) genotype II African swine fever virus (ASFV) isolated in Europe,Latvia 2017

A non‐haemadsorbing (non‐HAD) ASF virus (ASFV) genotype II, namely Lv17/WB/Rie1, was isolated from a hunted wild boar in Latvia in 2017. Domestic pigs experimentally infected with the non‐HAD ASFV developed a nonspecific or subclinical form of the disease. Two months later, these animals were fully protected when exposed to other domestic pigs infected with a related virulent HAD genotype II ASFV.     

Statistical Exploration of Local Transmission Routes for African Swine Fever in Pigs in the Russian Federation, 2007–2014

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.     

Genetic characterization of African swine fever virus isolates from soft ticks at the wildlife/domestic interface in Mozambique and identification of a novel genotype

African swine fever virus (ASFV ) is one of the most threatening infectious diseases of pigs. There are not sufficient data to indicate the importance of the sylvatic cycle in the spread and maintenance of the disease locally and potentially, globally. To assess the capacity to maintain ASF in the environment, we investigated the presence of soft tickreservoirs of ASFV in Gorongosa National Park (GNP ) and its surrounding villages. A total of 1,658 soft ticks were recovered from warthog burrows and pig pens at the wildlife/livestock interface of the GNP and viral DNA was confirmed by nested PCR in 19% of Ornithodoros porcinus porcinus and 15% of O. p. domesticus . However, isolation of ASFV was only achieved in approximately 50% of the PCR ‐positive samples with nineteen haemadsorbing virus isolates recovered. These were genotyped using a combination of partial sequencing of the B646L gene (p72 ) and analysis of the central variable region (CVR ) of the B602L gene. Eleven isolates were classified as belonging to genotype II and homologous to contemporary isolates from southern Africa, the Indian Ocean and eastern Europe. Three isolates grouped within genotype V and were similar to previous isolates from Mozambique and Malawi. The remaining five isolates constituted a new, previously unidentified genotype, designated genotype XXIV . This work confirms for the first time that the virus currently circulating in eastern Europe is likely to have a wildlife origin, and that the large diversity of ASFV maintained in wildlife areas can act as a permanent sources of different strains for the domestic pig value chain in Mozambique and beyond its boundaries. Their genetic similarity to ASFV strains currently spreading across Europe justifies the need to continue studying the sylvatic cycle in this African country and other parts of southern Africa in order to identify potential hot spots of ASF emergence and target surveillance and control efforts.     

Spatio‐temporal Analysis of African Swine Fever in Sardinia (2012–2014): Trends in Domestic Pigs and Wild Boar

African swine fever (ASF) is a notifiable viral disease affecting domestic pigs and wild boars that has been endemic in Sardinia since 1978. Several risk factors complicate the control of ASF in Sardinia: generally poor level of biosecurity, traditional breeding practices, illegal behaviour in movements and feeding of pigs, and sporadic occurrence of long‐term carriers. A previous study describes the disease in Sardinia during 1978–2013. The aim of this study was to gain more in‐depth knowledge of the spatio‐temporal pattern of ASF in Sardinia during 2012 to May 2014, comparing patterns of occurrence in domestic pigs and wild boar and identifying areas of local transmission. African swine fever notifications were studied considering seasonality, spatial autocorrelation, spatial point pattern and spatio‐temporal clusters. Results showed differences in temporal and spatial pattern of wild boar and domestic pig notifications. The peak in wild boar notifications (October 2013 to February 2014) occurred six months after than in domestic pig (May to early summer 2013). Notifications of cases in both host species tended to be clustered, with a maximum significant distance of spatial association of 15 and 25 km in domestic pigs and wild boars, respectively. Five clusters for local ASF transmission were identified for domestic pigs, with a mean radius and duration of 4 km (3–9 km) and 38 days (6–55 days), respectively. Any wild boar clusters were found. The apparently secondary role of wild boar in ASF spread in Sardinia could be explained by certain socio‐economic factors (illegal free‐range pig breeding or the mingling of herds. The lack of effectiveness of previous surveillance and control programmes reveals the necessity of employing a new approach). Results present here provide better knowledge of the dynamics of ASF in Sardinia, which could be used in a more comprehensive risk analysis necessary to introduce a new approach in the eradication strategy.     

Identification and phylogenetic characterization of bovine ephemeral fever virus (BEFV) of Middle Eastern lineage associated with 2018–2019 outbreaks in India

Bovine ephemeral fever virus (BEFV) is an evolving arbovirus reported across tropical, subtropical and temperate climatic zones globally. This study reveals prominent BEFV outbreaks in India, emerging annually during monsoons in subtropical areas accompanied by a congenial abundance of the vector population. PCR‐based detection of viral genomic RNA in the blood samples collected during outbreaks of 2018–2019 for the first time confirmed the presence of BEFV in India. Phylogenetic analysis based on the glycoprotein gene of BEFV showed the current isolates to have high sequence homology with Middle Eastern lineage with nearly 97%, identity to Turkey (BEFV Ad12/TUR) and Israel (Israel 2006) isolates.     

Tick‐borne pathogens in ticks (Acari: Ixodidae) collected from various domestic and wild hosts in Corsica (France), a Mediterranean island environment

Corsica is a mountainous French island in the north‐west of the Mediterranean Sea presenting a large diversity of natural environments where many interactions between humans, domestic animals and wild fauna occur. Despite this favourable context, tick‐borne pathogens (TBPs) have not systematically been investigated. In this study, a large number of TBPs were screened in ticks collected over a period of one year from domestic and wild hosts in Corsica. More than 1,500 ticks belonging to nine species and five genera (Rhipicephalus, Hyalomma, Dermacentor, Ixodes and Haemaphysalis) were analysed individually or pooled (by species, gender, host and locality). A real‐time microfluidic PCR was used for high‐throughput screening of TBP DNA. This advanced methodology enabled the simultaneous detection of 29 bacterial and 12 parasitic species (including Borrelia, Anaplasma, Ehrlichia, Rickettsia, Bartonella, Candidatus Neoehrlichia, Coxiella, Francisella, Babesia and Theileria). The Crimean–Congo haemorrhagic fever (CCHF) virus was investigated individually in tick species known to be vectors or carriers of this virus. In almost half of the tick pools (48%), DNA from at least one pathogen was detected and eleven species of TBPs from six genera were reported. TBPs were found in ticks from all collected hosts and were present in more than 80% of the investigated area. The detection of DNA of certain species confirmed the previous identification of these pathogens in Corsica, such as Rickettsia aeschlimannii (23% of pools), Rickettsia slovaca (5%), Anaplasma marginale (4%) and Theileria equi (0.4%), but most TBP DNA identified had not previously been reported in Corsican ticks. This included Anaplasma phagocytophilum (16%), Rickettsia helvetica (1%), Borrelia afzelii (0.7%), Borrelia miyamotoi (1%), Bartonella henselae (2%), Babesia bigemina (2%) and Babesia ovis (0.5%). The high tick infection rate and the diversity of TBPs reported in this study highlight the probable role of animals as reservoir hosts of zoonotic pathogens and human exposure to TBPs in Corsica.     

Diagnosis of Peste des Petits Ruminants in Wild and Domestic Animals in Xinjiang,China, 2013–2016

Peste des petits ruminants viruses (PPRVs) re‐emerged in China at the end of 2013 and then spread rapidly into 22 provinces through movement of live goats and sheep. In this study, 96 samples of domestic animals and 13 samples of wildlife were analysed for the presence of PPRV infection by ELISA or RT‐PCR. Of 96 samples from sheep and goats, 91 were PPRV positive, whereas all of the 13 samples from three wild species, Capra ibex (Capra ibex sibirica), argali (Ovis ammon) and Goitered gazelle (Gazella subgutturosa), were found to be positive. Five wildlife‐origin isolates from the above samples were identified as the lineage IV by a multiple alignment of the partial sequences in N gene.     

Development of a novel quantitative real‐time PCR assay with lyophilized powder reagent to detect African swine fever virus in blood samples of domestic pigs in China

African swine fever (ASF) is a devastating disease, which is causing huge economic losses in China. Therefore, it is urgent to provide a rapid, highly specific and sensitive diagnostic method for the detection of African swine fever virus (ASFV), the ASF infectious agent. In this study, a novel quantitative real‐time polymerase chain reaction (qPCR) assay with lyophilized powder reagents (LPR), targeting the major structural protein p72 gene, was established for the detection of ASFV. This assay had many advantages, such as saving time and money, good sensitivity and repeatability. The sensitivity of this assay was 100 copies/μl of ASFV plasmid templates, and the assay showed 10‐fold greater sensitivity than a qPCR assay recommended by OIE. Furthermore, specificity analysis showed that qPCR with LPR for ASFV had no cross‐reactivity with other important swine pathogens. In clinical diagnoses of 218 blood samples of domestic pigs in China, the positive rate of the diagnosis of ASFV by qPCR with the LPR and commercial kit reached 80.73% (176/218) and 76.61% (167/218) respectively. The coincidence rate between the two assays is 92.20% (201/218), and kappa value is 0.768 (p < .0001) by SPSS analysis. The overall agreement between the two assays was 95.87% (209/218). Further Pearson correlation and linear regression analysis showed a significant correlation between the two assays with an R² value of 0.9438. The entire procedure, from specimen processing to result reporting, can be completed within 2 hr. Our results demonstrated that the qPCR‐LPR assay is a good laboratory diagnostic tool for sensitive and efficient detection of ASFV.     

Genetic Characterization of Circulating African Swine Fever Viruses in Nigeria (2007–2015)

Sequencing and analysis of three discrete genome regions of African swine fever viruses (ASFV) from archival samples collected in 2007–2011 and active and passive surveillance between 2012 and 2015 in Nigeria were carried out. Analysis was conducted by genotyping of three single‐copy African swine fever (ASF) genes. The E183L and B646L genes that encode structural proteins p54 and p72, respectively, were utilized to delineate genotypes before intragenotypic resolution by characterization of the tetrameric amino acid repeat region within the hypervariable central variable region of the B602L gene. The results showed no variation in the p72 and p54 gene regions sequenced. Phylogeny of p72 sequences revealed that all the Nigerian isolates belonged to genotype I, while that of the p54 recovered the Ia genotype. Analysis of B602L gene revealed the differences in the number of tetrameric repeats. Four new variants (Tet‐15, Tet‐17a, Tet‐17b and Tet‐48) were recovered, while a fifth variant (Tet‐20) was the most widely distributed in the country displacing Tet‐36 reported previously in 2003–2006. The viruses responsible for ASF outbreaks in Nigeria are from very closely related but mutated variants of the virus that have been circulating since 1997. A practical implication of the genetic variability of the Nigerian viral isolates in this study is the need for continuous sampling and analysis of circulating viruses, which will provide epidemiological information on the evolution of ASFV in the field versus new incursion for informed strategic control of the disease in the country.     

Seroprevalence of Bovine Ephemeral Fever Virus in Domesticated and Wildlife Species during Epidemic and Inter‐epidemic Periods (2000–2009) in Israel

Bovine ephemeral fever (BEF) is an economically important vector‐borne viral disease of cattle and buffalo. It has been reported from most of the world's tropical and subtropical regions. In the last few decades, outbreaks of BEF have occurred in Israel almost every other year. Several serological studies have demonstrated a wide range of wild animal species that are positive for BEF virus (BEFV) antibodies. However, the question of whether wild animals and domesticated species other than cattle also play an important role in the maintenance and transmission of BEFV in Israel remains. Here, we examined the prevalence of anti‐BEFV antibodies in 942 samples collected from various wild, semi‐captive and domesticated animal species during the years 2000–2009 using the serum neutralization (SN) method. SN test revealed the presence of BEFV‐neutralizing antibodies in nine samples (0.96%), from three species: Bubalus bubalis (4/29, 13.79%), Gazella g. gazella (3/68, 4.44%) and Dama d. mesopotamica (2/296, 0.68%). All positive samples were collected in areas of earlier outbreaks. The low prevalence of positive animals and the solid correlation with prior outbreaks indicate that the tested species probably do not serve as virus reservoirs and may play only a minor role in the maintenance of BEFV in the Middle East.     

Herd‐level prevalence and incidence of porcine epidemic diarrhoea virus (PEDV) and porcine deltacoronavirus (PDCoV) in swine herds in Ontario,Canada

Porcine epidemic diarrhoea virus (PEDV ) and porcine deltacoronavirus (PDC oV) were first identified in Canada in 2014. Surveillance efforts have been instrumental in controlling both diseases. In this study, we provide an overview of surveillance components for the two diseases in Ontario (Canada), as well as PEDV and PDC oV incidence and prevalence measures. Swine herds located in the Province of Ontario, of any type, whose owners agreed to participate in a voluntary industry‐led disease control programme (DCP ) and with associated diagnostic or epidemiological information about the two swine coronaviruses, were eligible to be included for calculation of disease frequency at the provincial level. PEDV and PDC oV data stored in the industry DCP database were imported into the R statistical software and analysed to produce weekly frequency of incidence counts and prevalence counts, in addition to yearly herd‐level incidence risk and prevalence between 2014 and 2016. The yearly herd‐level incidence risk of PEDV , based on industry data, was 13.5%, 3.0% and 1.4% (95% CI : 11.1–16.2, 2.0–4.2, 0.8–2.3), while the yearly herd‐level incidence risk of PDC oV was 1.1%, 0.3%, and 0.1% (95% CI : 0.5–2.2, 0.1–0.9, 0.0–0.5), for 2014, 2015 and 2016, respectively. Herd‐level prevalence estimates for PEDV in the last week of 2014, 2015 and 2016 were 4.4%, 2.3% and 1.4%, respectively (95% CI : 3.1–6.0, 1.5–3.3, 0.8–2.2), while herd‐level prevalence estimates for PDC oV in the last week of 2014, 2015 and 2016 were 0.5%, 0.2% and 0.2%, respectively (95% CI : 0.1–1.2, 0.0–0.6, 0.0–0.6). Collectively, our results point to low and decreasing incidence risk and prevalence for PEDV and PDC oV in Ontario, making both diseases possible candidates for disease elimination at the provincial level.     

Appearance of US‐like porcine epidemic diarrhoea virus (PEDV) strains before US outbreaks and genetic heterogeneity of PEDVs collected in Northern Vietnam during 2012–2015

Porcine epidemic diarrhoea virus (PEDV ) is the aetiologic agent of porcine epidemic diarrhoea (PED ), a highly contagious enteric disease that is threatening the swine industry globally. Since PED was first reported in Southern Vietnam in 2009, the disease has spread throughout the country and caused substantial economic losses. To identify PEDV s responsible for the recent outbreaks, the full‐length spike (S) gene of 25 field PEDV strains collected from seven northern provinces of Vietnam was sequenced and analysed. The sequence analysis revealed that the S genes of Vietnamese PEDV s were heterogeneous and classified into four genotypes, namely North America and Asian non‐S INDEL , Asian non‐S INDEL , new S INDEL and classical S INDEL . This study reported the pre‐existence of US ‐like PEDV strains in Vietnam. Thirteen Vietnamese variants had a truncated S protein that was 261 amino acids shorter than the normal protein. We also detected one novel variant with an 8‐amino acid insertion located in the receptor‐binding region for porcine aminopeptidase N. Compared to the commercial vaccine strains, the emerging Vietnamese strains were genetically distant and had various amino acid differences in epitope regions and N‐glycosylation sites in the S protein. The development of novel vaccines based on the emerging Vietnamese strains may be contributive to the control of the current PED outbreaks.     

Emergence and spread of highly pathogenic avian influenza A(H5N8) in Europe in 2016‐2017

Circulation of highly pathogenic avian influenza (HPAI ) viruses poses a continuous threat to animal and public health. After the 2005–2006 H5N1 and the 2014–2015 H5N8 epidemics, another H5N8 is currently affecting Europe. Up to August 2017, 1,112 outbreaks in domestic and 955 in wild birds in 30 European countries have been reported, the largest epidemic by a HPAI virus in the continent. Here, the main epidemiological findings are described. While some similarities with previous HPAI virus epidemics were observed, for example in the pattern of emergence, significant differences were also patent, in particular the size and extent of the epidemic. Even though no human infections have been reported to date, the fact that A/H5N8 has affected so far 1,112 domestic holdings, increases the risk of exposure of humans and therefore represents a concern. Understanding the epidemiology of HPAI viruses is essential for the planning future surveillance and control activities.     

Faecal Escherichia coli as biological indicator of spatial interaction between domestic pigs and wild boar (Sus scrofa) in Corsica

On the Mediterranean island of Corsica, cohabitation between sympatric domestic pigs and Eurasian wild boar (Sus scrofa ) is common and widespread and can facilitate the maintenance and dissemination of several pathogens detrimental for the pig industry or human health. In this study, we monitored a population of free‐ranging domestic pigs reared in extensive conditions within a 800‐ha property located in Central Corsica which was frequently visited by a sympatric population of wild boar between 2013 and 2015. We used GPS collars to assess evidence of a spatially shared environment. Subsequently, we analysed by PFGE of Xba I‐restricted DNA if those populations shared faecal Escherichia coli clones that would indicate contact and compared these results with those collected in a distant (separated by at least 50 km) population of wild boar used as control. Results showed that one of eight wild boars sampled in the study area shed E. coli Xba I clones identical to clones isolated from domestic pig sounders from the farm, while wild boar populations sampled in distant parts of the study area shared no identical clone with the domestic pigs monitored. Interestingly, within the sampled pigs, two identical clones were found in 2013 and in 2015, indicating a long‐time persisting colonization type. Although the method of isolation of E. coli and PFGE typing of the isolates requires intensive laboratory work, it is applicable under field conditions to monitor potential infectious contacts. It also provides evidence of exchange of microorganisms between sympatric domestic pigs and wild boar populations.     

Assessment of interactions between African swine fever virus,bushpigs (Potamochoerus larvatus), Ornithodoros ticks and domestic pigs in north‐western Madagascar

Since its introduction in Madagascar in 1998, African swine fever (ASF) has severely affected national pig production and persists as a common disease in that country. Two of its natural hosts in the African continent, the bushpig (Potamochoerus larvatus) and tick vectors of the Ornithodoros moubata complex, are reported in west and central regions of the island. However, their role in the maintenance and transmission of the virus has been insufficiently studied. In this work, we tried to assess their potential role in the epidemiology of the disease in Madagascar, by assessing the levels of interaction between (i) ASF virus (ASFV) and bushpigs and (ii) between soft ticks and domestic and wild suids in north‐western Madagascar. Twenty‐seven sera and 35 tissue samples from bushpigs were collected and analysed for the presence of anti‐ASF antibodies and viral DNA. In addition, the sera from 27 bushpigs and 126 domestic pigs were analysed with an ELISA test for the detection of antibodies against salivary antigens from Ornithodoros ticks. No circulation of ASFV or anti‐ASFV antibodies nor anti‐tick antibodies were detected in bushpigs. However, seven of the domestic pig sera (5.6% of the total sample population) were antibody positive for O. moubata antigens. The probability of freedom from ASFV in the bushpig population using Bayesian statistical methods ranged between 73% and 84%. The probabilities of absence of anti‐tick antibodies in domestic and wild pigs were estimated at 63% and 71%, respectively. These preliminary results suggest that bushpigs are unlikely to play a significant role in the maintenance and transmission of ASFV in Madagascar. Nevertheless, further ASFV surveys are needed on that species to confirm this assumption. In addition, the presence of antibodies against O. moubata in domestic pigs suggests that soft ticks may be able to maintain ASFV within a domestic pig cycle in areas of Madagascar where they remain present.     

Description of Events Where African Buffaloes (Syncerus caffer) Strayed from the Endemic Foot‐and‐Mouth Disease Zone in South Africa, 1998–2008

African buffaloes (Syncerus caffer) are reservoir hosts of Southern African Territories (SAT) foot‐and‐mouth disease (FMD) virus strains. In South Africa, infected buffaloes are found in the FMD‐infected zone comprising the Kruger National Park (KNP) and its adjoining reserves. When these buffaloes stray into livestock areas, they pose a risk of FMD transmission to livestock. We assessed 645 records of stray buffalo events (3124 animals) from the FMD infected zone during 1998–2008 for (i) their temporal distribution, (ii) group size, (iii) age and gender composition, (iv) distance from the infected zone fence and (v) outcome reported for each event. A maximum entropy model was developed to evaluate spatial predictors of stray buffalo events and assess current disease control zones. Out of all buffaloes recorded straying, 38.5% escaped from the FMD infected zone during 2000/2001, following floods that caused extensive damage to wildlife fences. Escape patterns were not apparently influenced by season. The median size of stray groups was a single animal (IQR [1–2]). Adult animals predominated, comprising 90.4% (620/686) of the animals for which age was recorded. Of the 315 events with accurate spatial information, 204 (64.8%) were recorded within 1 km from the FMD infected zone. During late winter/spring (June–October), stray buffaloes were found significantly closer to the FMD infected zone (median = 0.3 km, IQR [0.1–0.6]). Less than 13% (40/315) of stray groups reached the FMD protection zone without vaccination, posing a higher risk of spreading FMD to these more susceptible livestock. Model outputs suggest that distance from the FMD infected zone, urban areas and permanent water sources contributed almost 85% to the spatial probability of stray buffalo events. Areas with a high probability for stray buffalo events were well covered by current disease control zones, although FMD risk mitigation could be improved by expanding the vaccination zone in certain areas.