First Outbreak of African Swine Fever in Wild Boar in Nepal.

This case report documents the first confirmed outbreak of African swine fever (ASF) in a wild boar (Sus scrofa) in Nepal. The case was identified in a wild boar carcass found in Shuklaphanta National Park in February 2023. Post-mortem findings, including splenomegaly, haemorrhagic lymph nodes and congested organs, were suggestive of ASF, which was confirmed by real-time PCR. Epidemiological evidence indicates potential transmission from nearby ASF-infected domestic pigs. This case underscores the critical need for rigorous biosecurity protocols, comprehensive surveillance and targeted wildlife management strategies to prevent further transmission between domestic pig and wild boar populations.

Navigating the threat of African swine fever: a comprehensive review.

African swine fever (ASF) is caused by Asfivirus and has become one of the most important diseases of swine in recent years. ASF was an endemic disease of the sub-Saharan Africa but later spread to various parts of the world. The infection in ticks and wild swine, alongside global pork trade, drives its spread and persistence. Once introduced to an area, the disease is difficult to eliminate due to sylvatic, domestic, and tick-swine transmission cycles. Because of the existence of various modes of transmission of the ASF virus, biosecurity measures have not been very successful. The line of treatment is not of much use and the outcome of this disease is usually fatal. The prognosis or the recovery of the animal depends on the virulence of the strain involved. Development of vaccines has been attempted but to date has not been very successful. This review focuses on the basic context of ASF, the challenges associated with it, and the options that might be available to prevent its occurrence which includes the different vaccine development strategies tried and tested till now.

Detection of the first recombinant African swine fever virus (genotypes I and II) in domestic pigs in Russia.

INTRODUCTION: African swine fever (ASF) is a contagious viral disease that affects pigs and wild boars, with a mortality rate of up to 100% in susceptible animals. The virus has been circulating in Europe and Asia since its introduction in 2007. Initially, all studied isolates were identified as genotype II, but in 2021 genotype I was reported in China. Later in 2023, the first recombinant virus of genotype I and II was identified in China, with an isolate dating back to 2021, this was followed by the detection of 6 recombinant isolates in Vietnam. METHODS: In this study, an ASFV isolate from the Primorsky Region of Russia obtained from a domestic pig was analyzed by sequencing several genome markers as well as the full genome. Eight pigs were infected with the isolate to assess its virulence. RESULTS: Virus replication in cell culture showed hemadsorption, while sequencing of genome markers clustered the isolate into both genotype I and genotype II. The whole-genome sequence showed that the Russian isolate shared a 99.99% identity with recombinant isolates described earlier in China. Experimental animals developed ASF disease after the introduction of a low dose of the virus (10 HAU50) and died within 7 days post-infection, presenting an acute form of the disease. CONCLUSION: This is the first report on recombinant ASFV in Russia's territory. The results once again confirm the transboundary nature of the disease, demonstrating the vulnerability of the global pig industry underscoring the need for developing new ASF vaccines effective against recombinant strains and emphasizing the importance of continuous molecular monitoring to detect emerging threats promptly.

Molecular characterization of emerging recombinant African swine fever virus of genotype I and II in Vietnam, 2023.

African swine fever virus (ASFV) recombinant strains pose new challenges for diagnosis and control. This study characterizes genotype I and II recombinant ASFV strains identified in northern Vietnam in 2023 through whole-genome sequencing and comparative genomic analysis. Seven ASFV-positive samples from six provinces were analyzed, with recombinant strains detected in Bac Giang, Phu Tho, and Vinh Phuc provinces. Isolates showed hemadsorption positivity despite having genotype I B646L, indicating their recombinant nature. Genome-wide analysis revealed 19 recombination breakpoints consistent with Chinese recombinant strains. Vietnamese isolates shared 99.86-99.98% nucleotide identity with Chinese recombinants, forming a distinct monophyletic group. Comparative analysis identified 50 SNPs and INDELs, with 39 variations found across Vietnamese strains, distinguishing them from Chinese isolates. Unique genetic markers in C962R, I329L, and MGF 505-11L genes distinguished Vietnamese recombinants from Chinese counterparts, while mutations in C122R and NP1450L differentiated all recombinants from parental genotypes. The central variable region (CVR) of the B602L gene showed diversity among Vietnamese isolates, while the I73R-I329L intergenic regions were recognized as in the IGR2 group. This study enhances understanding of recombinant ASFV evolution through homologous recombination and identifies new genetic markers for improved detection and characterization. The observed genetic diversity highlights challenges for existing diagnostic methods and vaccine development, emphasizing the need for continued surveillance and research into the functional implications of these genetic variations on ASFV pathogenicity and transmissibility.

Enhancing infection control practices and biosecurity plans on Swedish pig farms: insights, challenges, and strategies.

BACKGROUND: African swine fever (ASF) poses a threat to the global pig industry, leading to significant economic losses and widespread disruptions in pig farming and associated sectors. In September 2023, the first case of ASF in Swedish wild boar triggered immediate responses from authorities, including the establishment of restricted zones and culling measures. A new ASF certification programme for pig herds was initiated to improve biosecurity and proactive disease management. This survey aimed to assess the sentiments and actions of Swedish pig farmers six months post-outbreak, particularly regarding biosecurity measures. Such information is important to improve preparedness for future disease threats. A questionnaire was distributed to members of the Swedish pig producers' organisation. RESULTS: A total of 113 farmers responded (response rate 27%), with the majority considering the risk of ASF reappearing in Sweden as high. The estimated cost for connecting the farms to the ASF certification programme varied greatly, with a majority identifying cost as a substantial hurdle. While many farmers sought biosecurity advice from veterinarians, 43% had not implemented suggested measures. Over one third had not received concrete measures that would fit their farms, and 14% had not received any biosecurity advice from veterinarians at all. Discussions among farmers emphasized concerns about ASF outbreaks, transmission mechanisms, and regulatory compliance, highlighting the importance of ongoing communication and knowledge exchange to address the challenges posed by ASF effectively. Additionally, participants also mentioned the role of dense wild boar populations and shortcomings in municipal food waste management as important risk factors. CONCLUSIONS: The responding farmers expressed widespread concern about new ASF outbreaks. A majority identified cost as a substantial hurdle for joining the ASF certification programme. While many farmers consulted veterinarians for advice on biosecurity, a significant number had yet to implement suggested measures and one third had not received specific guidance suitable for their farms. Stakeholder conversations highlighted concerns about ASF outbreaks, transmission, and compliance. They also discussed the role of dense wild boar populations and issues with municipal food waste management as significant risk factors for ASF.

Analysis of the Unique Historical Isolate of African Swine Fever Virus Isolate Spencer from Outbreaks in 1951.

African swine fever (ASF) is a deadly hemorrhagic disease of domestic and wild swine that was first described in the early 20th century after the introduction of European pigs to Kenya. The etiological agent, the African swine fever virus (ASFV), is a large DNA virus within the Asfarviridae family that is broadly categorized epidemiologically into genotypes based on the nucleotide sequence of B646L, the gene encoding the major capsid protein p72. ASF outbreaks in Africa have been linked historically to 25 genotypes by p72 nucleotide analysis and, recently, to 6 genotypes by amino acid comparison, whereas global outbreaks of ASF outside of Africa have only been linked to 2 genotypes: genotype I, which led to an outbreak in Europe during the 1960s that later spread to South America, and genotype II, responsible for the current pandemic that began in Georgia in 2007 and has since spread to Europe, Asia, and Hispaniola. Here, we present an analysis of the genome of ASFV Spencer, an isolate that was collected in 1951 near Johannesburg, South Africa. While nucleotide analysis of Spencer indicates the p72 coding sequence is unique, differentiating from the closest reference by five nucleotides, the predicted amino acid sequence indicates that it is 100% homologous to contemporary genotype 1. Full genome analysis reveals it is more similar to Mkuzi1979 and encodes genes that share similarity with either genotype 1 or genotype 2 outbreak strains.

Genetic Characterization of African Swine Fever Italian Clusters in the 2022-2023 Epidemic Wave by a Multi-Gene Approach.

The first report of African swine fever virus (ASFV) genotype II in Italy in 2022 marked the beginning of a significant invasion in at least eight Italian regions with different infection clusters. In this study, we used the multi-gene approach to investigate the epidemiological associations between ASFV strains causing cases and outbreaks in wild boar and pigs in Italy from January 2022 to the end of 2023. Our results confirm that all the tested ASFV-positive Italian samples belonged to genotype II and show high homology with genotype II ASFV sequences previously collected in Eurasian countries. Molecular characterization revealed the presence of four genetic groups in Italy. The majority of African swine fever (ASF) samples analyzed in the current study (72%) belonged to genetic group 3, which was the most representative in Europe. The results also provide evidence of the prevalence of genetic group 19 (15.9%). In addition, we identified new putative genetic groups, genetic group 25 (9.1%) and genetic group 26 (3.0%), which have never been described before. This is the first detailed report on the molecular characterization of more than 130 ASFV strains circulating in Italy.

A Retrospective Analysis Reveals That the 2021 Outbreaks of African Swine Fever Virus in Ghana Were Caused by Two Distinct Genotypes.

African swine fever virus (ASFV) is the causative agent of African swine fever (ASF), a highly infectious and lethal disease of domesticated swine. Outbreaks of ASF have been mostly restricted to the continent of Africa. The outbreaks that have occurred outside of Africa were controlled by extensive depopulation of the domesticated pig population. However, in 2007, an outbreak occurred in the country of Georgia, where ASFV infected wild pigs and quickly spread across eastern Europe. Since the reintroduction of ASF into Europe, variants of the current pandemic strain, ASFV Georgia 2007/01 (ASFV-G), which is classified as Genotype 2 based on p72 sequencing, have been reported in countries within western Europe, Asia, and the island of Hispaniola. Additionally, isolates collected in 2020 confirmed the presence of variants of ASFV-G in Nigeria. Recently, we reported similar variants of ASFV-G collected from domestic pigs suspected of dying of ASF in Ghana in 2022. Here, we retroactively report, based on full-length sequencing, that similar variants were present in Ghana in 2021. The SNP analysis revealed derivatives of ASFV with distinct genetic markers. Furthermore, we identified three full-length ASFV genomes as Genotype 1, indicating that there were two genotypes circulating in proximity during the 2021 ASF outbreaks in Ghana.

Identifying sites where wild boars can consume anthropogenic food waste with implications for African swine fever.

Wild boar population dynamics promote the increase in numbers and distribution of the species in Eurasia, leading to a rise in the interaction with human activities, as well as generating problems with the management of certain infectious diseases, most notably African swine fever (ASF). ASF virus possesses high stability in several contaminated pork and pork products that can be a source of indirect transmission to susceptible hosts habituated to anthropogenic food waste. This transmission route is a concerning threat for the dispersion of the disease, primarily into unaffected areas given the worldwide widespread distribution of the disease and the increase of wild boar contact with humans. Thus, in this study, a straightforward tool to assess the relative risk of wild boar natural populations potentially consuming food waste is presented using synthetic data. Three risk groups were defined related to urban areas, travel, and leisure. The surrounding quality of habitat of wild boar was used to obtain the relative risk of wild boar potentially consuming anthropogenic food waste. To assign the relative risk to the corresponding risk unit, we also included the population for the urban areas group, and traffic volume for the travel risk group. The leisure group had higher scaled risk scores, followed by the urban areas group. Higher risk was found in the edges of the study area where more natural landscapes are found. The implications of this risk are discussed focusing on the context of ASF transmission. The outputs can help prioritize decision-making in terms of the improvement of preventive measures against the habituation of wild boar to anthropogenic food waste and ASFV introduction in a given study area.

Epidemiology and ecology of the sylvatic cycle of African Swine Fever Virus in Kenya.

African Swine Fever (ASF) is caused by a DNA virus (AFSV) maintained and transmitted by the Argasid ticks. The re-emergence of the disease in Africa coupled with its rapid spread globally is a threat to the pig industry, food security and livelihoods. The ecology and epidemiology of the ASFV sylvatic cycle, especially in the face of changing land use and land cover, further compounds the menace and impacts of this disease in Kenya. The study aimed to determine the occurrence and distribution of ASFV seroprevalence in warthog populations, the tick vectors and extent of tick infestation of warthog burrows, and the genotypes of ASFV in soft ticks in Kenya. Warthogs from different parts of Kenya were captured and venous blood was centrifuged to harvest sera. Warthog burrows were examined for their conditions and to extract ticks. Sera were analyzed for antibodies against ASFV using a commercial ELISA kit coated with p32 ASFV recombinant protein. Ticks were pooled, DNA extracted and the p72 gene of the ASFV was amplified by qPCR and conventional PCR. The overall seroprevalence of ASFV in warthogs was 87.5 %. A total of 228 warthog burrows were examined and 2154 argasid ticks were extracted from the burrows. Tick pools from Kigio Farm and Lewa Wildlife Conservancies were ASFV-positive by qPCR and conventional PCR. ASFV was further confirmed by the Twist Comprehensive Viral Research Panel (TCVRP), which also identified the argasid ticks as Ornithodoros porcinus. The ticks were infected with virus genotype IX, and their occurrence overlaps with regions of previous ASF outbreaks in domestic pigs. Further, Viruses that could be tick endosymbionts/commensals or due to bloodmeal were detected in ticks by TCVRP; Porcine type-C oncovirus; Pandoravirus neocaledonia; Choristoneura fumiferana granulovirus; Enterobacteria phage p7; Leporid herpesvirus 4 isolate; 5; Human Lymphotropic virus; Human herpesvirus 5. In conclusion, our results suggest that infected Ornithodoros spp. seems to have a rich virome, which has not been explored but could be exploited to inform ASF control in Kenya. Further, the ecology of Ornithodoros spp. and burrow-use dynamics are complex and more studies are needed to understand these dynamics, specifically in the spread of ASFV at the interface of wild and domestic pigs. Further, our results provide evidence of genotype IX ASFV sylvatic cycle which through O. porcinus tick transmission has resulted in high exposure of adult common warthogs. Finally, the co-circulation of ASFV genotype IX in the same location with past ASF outbreaks in domestic pigs and presently in ticks brings to focus the role of the interface and ticks on virus transmission to pigs and warthogs.

Perceptions and practices of Swedish wild boar hunters in relation to African swine fever before the first outbreak in Sweden.

BACKGROUND: The first outbreak of African Swine Fever (ASF) in Sweden was detected in 2023 in wild boar. This study was conducted before the first ASF outbreak with the objective of investigating Swedish hunters' perceptions and practices pertaining to ASF ahead of any potential future outbreak. A mixed-methods interview study with Swedish wild boar hunters, consisting of focus group discussions and a questionnaire, was undertaken between October 2020 and December 2021. Six focus groups were conducted online, and an online questionnaire with questions related to practices and habits concerning hunting, the use of bait and hunting trips was sent to all members of the Swedish Hunting and Wildlife Association. A total of 3244 responses were received. RESULTS: Three general themes were identified in a thematic analysis of the data from the focus groups: hunters are willing to engage in ASF prevention and control, simplicity and feasibility are crucial for the implementation of reporting, sampling and control measures, and more information and the greater involvement of the authorities are required in ASF prevention and control. Results from the questionnaire showed that the use of bait was common. Products of animal origin were rarely used for baiting; the most common product used was maize. Hunting trips abroad, especially outside of the Nordic countries, were uncommon. CONCLUSIONS: Hunting tourism and the use of bait do not seem to constitute a major risk for the introduction of ASF to wild boar populations in Sweden. The accessibility of relevant information for each concerned stakeholder and the ease of reporting and sampling are crucial to maintain the positive engagement of hunters.

Spatio-temporal clustering of African swine fever virus (Asfarviridae: Asfivirus) circulating in the Kaliningrad region based on three genome markers.

INTRODUCTION: The rapid spread of African swine fever in the Kaliningrad region makes it necessary to use the methods of molecular epidemiology to determine the dynamics and direction of ASF spread in this region of Russia. The aim of the study was to determine single nucleotide polymorphisms within molecular markers K145R, O174L and MGF 505-5R of ASFVs isolated in Kaliningrad region and to study the circulating of the pathogen in European countries by subgenotyping and spatio-temporal clustering analysis. MATERIALS AND METHODS: Blood samples from living domestic pigs and organs from dead domestic pigs and wild boars, collected in the Kaliningrad region between 2017 and 2022 were used. Virus isolation was carried out in porcine bone-marrow primary cell culture. Amplicons of genome markers were amplified by PCR with electrophoretic detection and subsequent extraction of fragments from agarose gel. Sequencing was performed using the Sanger method. RESULTS: The circulation of two genetic clusters of ASFV isolates on the territory of the Kaliningrad has been established: epidemic (K145R-III, MGF 505-5R-II, O174L-I - 94.3% of the studied isolates) and sporadic (K145R-II, MGF 505-5R-II, O174L-I - 5.7%). CONCLUSION: The broaden molecular genetic surveillance of ASFV isolates based on sequencing of genome markers is necessary in the countries of the Eurasian continent to perform a more detailed analysis of ASF spread between countries and within regions.

Geospatial analysis for strategic wildlife disease surveillance: African swine fever in South Korea (2019-2021).

Since the confirmation of African swine fever (ASF) in South Korea in 2019, its spread, predominantly in wild boars, has been a significant concern. A key factor in this situation is the lack of identification of risk factors by surveillance bias. The unique orography, characterized by high mountains, complicates search efforts, leading to overlooked or delayed case detection and posing risks to the swine industry. Additionally, shared rivers with neighboring country present a continual threat of virus entry. This study employs geospatial analysis and statistical methods to 1) identify areas at high risk of ASF occurrence but possibly under-surveilled, and 2) indicate strategic surveillance points for monitoring the risk of ASF virus entry through water bodies and basin influences. Pearson's rho test indicated that elevation (rho = -0.908, p-value < 0.001) and distance from roads (rho = -0.979, p-value < 0.001) may have a significant impact on limiting surveillance activities. A map of potential under-surveilled areas was created considering these results and was validated by a chi-square goodness-of-fit test (X-square = 208.03, df = 1, p-value < 0.001). The strong negative correlation (rho = -0.997, p-value <0.001) between ASF-positive wild boars and distance from water sources emphasizes that areas surrounding rivers are one of the priority areas for monitoring. The subsequent hydrological analyses provided important points for monitoring the risk of virus entry via water from the neighboring country. This research aims to facilitate early detection and prevent further spread of ASF.

High mortality in free-ranging wild boars associated with African swine fever virus in India.

The present study focuses on the pathological and molecular characterization of African swine fever virus (ASFV) associated with an outbreak in wild boars in two national parks in southern India in 2022-2023. Significant mortality was observed among free-ranging wild boars at Bandipur National Park, Karnataka, and Mudumalai National Park, Tamil Nadu. Extensive combing operations were undertaken in both national parks, spanning an area of around 100 km2, originating from the reported epicenter, to estimate the mortality rate. Recovered carcasses were pathologically examined, and ASFV isolates was genetically characterized. Our findings suggested spillover infection of ASFV from nearby domestic pigs, and the virus was equally pathogenic in wild boars and domestic pigs. ASFV intrusion was reported in the Northeastern region of the country, which borders China and Myanmar, whereas the current outbreak is very distantly located, in southern India. Molecular data will help in tracing the spread of the virus in the country.

Characterization of an African swine fever virus outbreak in India and comparative analysis of immune genes in infected and surviving crossbreed vs. indigenous Doom pigs.

Since 2020, African swine fever (ASF) has affected all pig breeds in Northeast India except Doom pigs, a unique indigenous breed from Assam and the closest relatives of Indian wild pigs. ASF outbreaks result in significant economic losses for pig farmers in the region. Based on sequencing and phylogenetic analysis of the B646L (p72) gene, it has been determined that ASFV genotype II is responsible for outbreaks in this region. Recent studies have shown that MYD88, LDHB, and IFIT1, which are important genes of the immune system, are involved in the pathogenesis of ASFV. The differential expression patterns of these genes in surviving ASFV-infected and healthy Doom breed pigs were compared to healthy controls at different stages of infection. The ability of Doom pigs to withstand common pig diseases, along with their genetic resemblance to wild pigs, make them ideal candidates for studying tolerance to ASFV infection. In the present study, we investigated the natural resistance to ASF in Doom pigs from an endemic area in Northeast India. The results of this study provide important molecular insights into the regulation of ASFV tolerance genes.

An analysis of the social, cultural, and ecological factors that affect the implementation of biosecurity measures on smallholder commercial swine farms in Italy in the context of an emerging African Swine Fever outbreak.

African Swine Fever (ASF) is a contagious viral disease that infects wild and domesticated swine. In early 2022, the virus was found in wild boar in the Apennine mountains of mainland Italy.2 Since then, it has spread from wild boar to domesticated swine. To control the spread of ASF, an effective surveillance system and the implementation of strict biosecurity measures on farms are required yet are unevenly implemented across husbandry systems. Smallholder farms in particular are known to have low levels of biosecurity. In the Apennine mountains of Italy, small commercial farms have been found to have low levels of biosecurity despite being located in areas with high densities of wild boar, and, hence, being high-risk sites for potential ASF incursion and subsequent diffusion. To address the question as to why the level of biosecurity is low, interviews and participant observation were conducted with smallholder commercial farmers. The interviews identified the social, cultural, and ecological factors that affect the implementation of biosecurity measures in small commercial swine farms in the Apennines. Farmers expressed knowledge of priority biosecurity measures and an overall willingness to follow rules and regulations; however, the application of the measures in practice was uneven across farms. Economic, political, and ecological factors as well as farmer beliefs about biosecurity emerged as important factors affecting the implementation of biosecurity measures. These include economic constraints, challenges posed by the mountain environment, a shifting regulatory environment, and ideas about animal welfare. Other important factors include cultural factors such as the use of traditional agricultural methods and norms about customer access to animals, time constraints and the perceived hassle of implementing the measures, farmer age, farmer relationships with government officials and veterinarians, and the role of pigs in reducing farm waste. The study confirmed that wild boar are present in high numbers and in close proximity to smallholder commercial farms in the Apennines.

African swine fever virus DNA is present in non-biting flies collected from outbreak farms in Romania.

BACKGROUND: African swine fever (ASF) is a highly contagious and severe haemorrhagic disease of Suidae, with mortalities that approach 100 percent. Several studies suggested the potential implication of non-biting dipterans in the spread of ASFV in pig farms due to the identification of the ASFV DNA. However, to our knowledge, no study has evaluated the viral DNA load in non-biting dipterans collected in outbreak farms and no risk factors have been analysed. In this context, our study aimed to analyse the risk factors associated with the presence of non-biting dipterans collected from ASF outbreaks in relation to the presence and load of viral DNA. METHODS: Backyard farms (BF), type A farms (TAF), and commercial farms (CF), were targeted for sampling in 2020. In 2021, no BF were sampled. Each farm was sampled only once. The identification of the collected flies to family, genus, or species level was performed based on morphological characteristics using specific keys and descriptions. Pools were made prior to DNA extraction. All extracted DNA was tested for the presence of the ASFV using a real-time PCR protocol. For this study, we considered every sample with a CT value of 40 as positive. The statistical analysis was performed using Epi Info 7 software (CDC, USA). RESULTS: All collected non-biting flies belonged to five families: Calliphoridae, Sarcophagidae, Fanniidae, Drosophilidae, and Muscidae. Of the 361 pools, 201 were positive for the presence of ASFV DNA. The obtained CT values of the positive samples ranged from 21.54 to 39.63, with a median value of 33.59 and a mean value of 33.56. Significantly lower CT values (corresponding to higher viral DNA load) were obtained in Sarcophagidae, with a mean value of 32.56; a significantly higher number of positive pools were noticed in August, mean value = 33.12. CONCLUSIONS: Our study brings compelling evidence of the presence of the most common synanthropic flies near domestic pig farms carrying ASFV DNA, highlighting the importance of strengthening the biosecurity measures and protocols for prevention of the insect life cycle and distribution.

Porcine Circovirus Type 3 (PCV3) in Poland: Prevalence in Wild Boar Population in Connection with African Swine Fever (ASF).

Human health is dependent on food safety and, therefore, on the health of farm animals. One of the most significant threats in regard to swine diseases is African swine fever (ASF). Infections caused by porcine circoviruses (PCVs) represent another important swine disease. Due to the ubiquitous nature of PCV2, it is not surprising that this virus has been detected in ASFV-affected pigs. However, recent data indicate that coinfection of PCV3 and ASFV also occurs. It is still unclear whether PCV infection plays a role in ASFV infection, and that subject requires further analysis. The aim of this study was to assess whether PCV3 and PCV4 are present in the wild boar population in Poland (real-time PCR). The analysis was performed on wild boar samples collected for routine ASF surveillance in Poland, between 2018 and 2021. By extension, the obtained data were compared in regard to ASFV presence in these samples, thus investigating the odds of ASFV infection on the grounds of the PCV carrier state in free-ranging Suidae in Poland. In addition, sequencing of PCV3 and phylogenetic analysis were performed, based on a full genome and a capsid gene. In the current study, we demonstrated the high prevalence of PCV3 in the wild boar population in Poland; meanwhile, PCV4 was not detected. The odds of ASFV infection on the grounds of the PCV3 carrier state in free-ranging Suidae in Poland was more than twice as high. Ten full genome sequences of PCV3 were obtained, all of them belonging to clade 3a. The similarity between them was in the range of 98.78-99.80%.

Novel estimation of African swine fever transmission parameters within smallholder villages in Lao P.D.R.

African Swine Fever (ASF) disease transmission parameters are crucial for making response and control decisions when faced with an outbreak, yet they are poorly quantified for smallholder and village contexts within Southeast Asia. Whilst disease-specific factors - such as latent and infectious periods - should remain reasonably consistent, host, environmental and management factors are likely to affect the rate of disease spread. These differences are investigated using Approximate Bayesian Computation with Sequential Monte-Carlo methods to provide disease parameter estimates in four naïve pig populations in villages of Lao People's Democratic Republic. The villages represent smallholder pig farmers of the Northern province of Oudomxay and the Southern province of Savannakhet, and the model utilised field mortality data to validate the transmission parameter estimates over the course of multiple model generations. The basic reproductive number between-pigs was estimated to range from 3.08 to 7.80, whilst the latent and infectious periods were consistent with those published in the literature for similar genotypes in the region (4.72 to 6.19 days and 2.63 to 5.50 days, respectively). These findings demonstrate that smallholder village pigs interact similarly to commercial pigs, however the spread of disease may occur slightly slower than in commercial study groups. Furthermore, the findings demonstrated that despite diversity across the study groups, the disease behaved in a consistent manner. This data can be used in disease control programs or for future modelling of ASF in smallholder contexts.

Modelling African swine fever introduction in diverse Australian feral pig populations.

African swine fever (ASF) is a viral disease that affects domestic and feral pigs. While not currently present in Australia, ASF outbreaks have been reported nearby in Indonesia, Timor-Leste, and Papua New Guinea. Feral pigs are found in all Australian states and territories and are distributed in a variety of habitats. To investigate the impacts of an ASF introduction event in Australia, we used a stochastic network-based metapopulation feral pig model to simulate ASF outbreaks in different regions of Australia. Outbreak intensity and persistence in feral pig populations was governed by local pig recruitment rates, population size, carcass decay period, and, if applicable, metapopulation topology. In Northern Australia, the carcass decay period was too short for prolonged persistence, while endemic transmission could possibly occur in cooler southern areas. Populations in Macquarie Marshes in New South Wales and in Namadgi National Park in the Australian Capital Territory had the highest rates of persistence. The regions had different modes of transmission that led to long-term persistence. Endemic Macquarie Marshes simulations were characterised by rapid transmission caused by high population density that required a fragmented metapopulation to act as a bottleneck to slow transmission. Endemic simulations in Namadgi, with low density and relatively slow transmission, relied on large, well-connected populations coupled with long carcass decay times. Despite the potential for endemic transmission, both settings required potentially unlikely population sizes and dynamics for prolonged disease survival.