Why is African swine fever still present in Sardinia?

African swine fever (ASF ) is an infectious disease of swine that has been present in Sardinia since 1978. Soon after introduction of the disease, several control and eradication programmes were established with limited success. Some researchers attributed the persistence of the disease in central and eastern areas to certain socio‐economic factors, the existence of some local and traditional farming practices (i.e., unregistered free‐ranging pigs known as brado animals) and the high density of wild boar in the region. In the past, scarcity of swine data in Sardinia complicated the evaluation and study of ASF on the island. More complete, accurate and reliable information on pig farms has become available as a result of the most recent eradication programmes. Here, we perform statistical modelling based on these data and the known distribution of domestic pig and wild boar to identify the main risk factors that have caused ASF persistence in Sardinia. Our results categorized, identified and quantified nine significant risk factors, six of which have not been previously described. The most significant factors were the number of medium‐sized farms, the presence of brado animals and the combination of estimated wild boar density and mean altitude above sea level. Based on these factors, we identified regions in eastern and central Sardinia to be at greatest risk of ASF persistence; these regions are also where the disease has traditionally been endemic. Based on these risk factors, we propose specific control measures aimed at mitigating such risks and eradicating ASF from the island.     

Surveillance and control of African Swine Fever in free‐ranging pigs in Sardinia

African swine fever (ASF) is a notifiable infectious disease, caused by the ASF virus (ASFV), which is a DNA virus belonging to the family Asfarviridae, genus Asfivirus. This disease has gained importance in the last decade after its spread in several countries in Eastern and Central Europe, and more recently, in China. Despite the efforts made to eradicate it, ASF is still present on the Mediterranean island of Sardinia (Italy) and has been since 1978. ASF risk factors on the island have been analysed in previous studies; the role of free‐ranging pigs in virus persistence has been suggested, but has not been fully elucidated. The most recent eradication plan provides more stringent measures to combat free‐ranging pigs and any kind of illegality in the pig sector. From December 2017 to June 2018, a total of 29 depopulation actions were performed in 13 municipalities in central Sardinia, during which 2,281 free‐ranging pigs were culled and more than 50% of them were tested for ASFV and antibody presence (1,218 and 1,416, respectively). A total of 651 pigs were seropositive, with a mean seroprevalence of 53.4% (CI 95% = 50.6–56.3), and 38 were ASFV positive (virus prevalence = 2.6%; CI 95% = 2.1–3.0). To the best of our knowledge, the present study is the first to provide a complete evaluation of this millennial system of pig farming and ASFV prevalence in free‐ranging pigs. Furthermore, it has emphasised the necessity of combining the maintenance of an epidemiological surveillance program with continuous education of farmers and other people involved in pig husbandry, based on cultural and economic aspects.     

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.     

Serological Surveillance and Direct Field Searching Reaffirm the Absence of Ornithodoros Erraticus Ticks Role in African Swine Fever Cycle in Sardinia

African swine fever (ASF), one of the most important diseases of swine, has been endemic in the Italian island of Sardinia for more than 35 years. During these decades, several strategies and eradication efforts have been implemented in the island with limited success. Strong climatic and ecological similarities exist between Sardinia and one area of the Iberian Peninsula where Ornithodoros erraticus ticks were involved in the persistence of ASF from 1960 to 1995. This fact leads to the hypothesis that, potentially, Ornithodoros ticks could be also involved in the ASF cycle in Sardinia, thus accounting for some of the reoccurring ASF outbreaks in this island. Initial efforts aimed at detection of Ornithodoros ticks in Sardinia were performed during the 1970s/1980s with no positive results. Accordingly, the absence of Ornithodoros ticks in Sardinia has been generally accepted. However, since a new and reinforced ASF eradication programme has been recently launched in Sardinia, it is essential to clarify the presence and role of these soft ticks in the epizootiology of ASF in this island. For that purpose, 1767 porcine serum samples collected from all around the island (1261 from domestic and 506 from wild boar) were analysed by ELISA for antibodies to salivary antigens of Ornithodoros erraticus. In addition, Ornithodoros ticks were directly searched in a number of pig premises that have suitable habitats for these ticks and were located in areas repeatedly affected by ASF. Only one serum sample resulted positive in the serological assay, and no Ornithodoros ticks were collected in none of the premises. These results indicate that these soft tick species are not involved in the epizootic cycle of ASF in Sardinia and highlight the importance of controlling other risk factors still present in the island for effectively eradicate the disease.     

Understanding African Swine Fever infection dynamics in Sardinia using a spatially explicit transmission model in domestic pig farms

African swine fever virus (ASFV ) has been endemic in Sardinia since 1978, resulting in severe losses for local pig producers and creating important problems for the island's veterinary authorities. This study used a spatially explicit stochastic transmission model followed by two regression models to investigate the dynamics of ASFV spread amongst domestic pig farms, to identify geographic areas at highest risk and determine the role of different susceptible pig populations (registered domestic pigs, non‐registered domestic pigs [brado ] and wild boar) in ASF occurrence. We simulated transmission within and between farms using an adapted version of the previously described model known as Be‐FAST . Results from the model revealed a generally low diffusion of ASF in Sardinia, with only 24% of the simulations resulting in disease spread, and for each simulated outbreak on average only four farms and 66 pigs were affected. Overall, local spread (indirect transmission between farms within a 2 km radius through fomites) was the most common route of transmission, being responsible for 98.6% of secondary cases. The risk of ASF occurrence for each domestic pig farm was estimated from the spread model results and integrated in two regression models together with available data for brado and wild boar populations. There was a significant association between the density of all three populations (domestic pigs, brado , and wild boar) and ASF occurrence in Sardinia. The most significant risk factors were the high densities of brado (OR = 2.2) and wild boar (OR = 2.1). The results of both analyses demonstrated that ASF epidemiology and infection dynamics in Sardinia create a complex and multifactorial disease situation, where all susceptible populations play an important role. To stop ASF transmission in Sardinia, three main factors (improving biosecurity on domestic pig farms, eliminating brado practices and better management of wild boars) need to be addressed.     

Knowledge,Attitudes and Practices Related to African Swine Fever Within Smallholder Pig Production in Northern Uganda

Uganda is a low‐income country with the largest pig population in East Africa. Pig keeping has a large potential, commercially and as a tool for poverty reduction, but African swine fever (ASF) is a major hurdle for development of the sector. The objective of this study was to evaluate knowledge, attitudes and practices related to ASF in the smallholder pig production value chain in northern Uganda. The study included three separate series of participatory rural appraisals (PRA), comprising purposively selected farmers and other actors in the pig production value chain. In the PRAs, various participatory epidemiology tools were used. A total of 49 PRAs and 574 participants, representing 64 different villages, were included. The results indicate that participants were well aware of the clinical signs of ASF, routes for disease spread and measures for disease control. However, awareness of the control measures did not guarantee their implementation. A majority of middlemen and butchers acknowledged having sold live pigs, carcasses or pork they believed infected with ASF. Outbreaks of ASF had a strong negative impact on participants’ socio‐economic status with loss of revenue and reversal into more severe poverty. In conclusion, lack of knowledge is not what is driving the continuous circulation of ASF virus in this setting. To control ASF and reduce its impact, initiatives that stimulate changes in management are needed. Because the behaviour of all actors in the value chain is largely influenced by the deep rural poverty in the region, this needs to be combined with efforts to reduce rural poverty.     

Epidemiology of African swine fever in Africa today: Sylvatic cycle versus socio‐economic imperatives

African swine fever (ASF) is believed to have evolved in eastern and southern Africa in a sylvatic cycle between common warthogs (Phacochoerus africanus) and argasid ticks of the Ornithodoros moubata complex that live in their burrows. The involvement of warthogs and possibly other wild suids in the maintenance of ASF virus means that the infection cannot be eradicated from Africa, but only prevented and controlled in domestic pig populations. Historically, outbreaks of ASF in domestic pigs in Africa were almost invariably linked to the presence of warthogs, but subsequent investigations of the disease in pigs revealed the presence of another cycle involving domestic pigs and ticks, with a third cycle becoming apparent when the disease expanded into West Africa where the sylvatic cycle is not present. The increase in ASF outbreaks that has accompanied the exponential growth of the African pig population over the last three decades has heralded a shift in the epidemiology of ASF in Africa, and the growing importance of the pig husbandry and trade in the maintenance and spread of ASF. This review, which focuses on the ASF situation between 1989 and 2017, suggests a minor role for wild suids compared with the domestic cycle, driven by socio‐economic factors that determine the ability of producers to implement the control measures needed for better management of ASF in Africa.     

Investigation into the Epidemiology of African Swine Fever Virus at the Wildlife – Domestic Interface of the Gorongosa National Park,Central Mozambique

An epidemiological study of African swine fever (ASF) was conducted between March 2006 and September 2007 in a rural area adjacent to the Gorongosa National park (GNP) located in the Central Mozambique. Domestic pigs and warthogs were sampled to determine the prevalence of antibodies against ASF virus and the salivary antigens of Ornithodoros spp. ticks, while ticks collected from pig pens were tested for the presence of ASFV. In addition, 310 framers were interviewed to gain a better understanding of the pig value chain and potential practices that could impact on the spread of the virus. The sero‐prevalence to ASFV was 12.6% on farms and 9.1% in pigs, while it reached 75% in warthogs. Approximately 33% of pigs and 78% of warthogs showed antibodies against salivary antigens of ticks. The differences in sero‐prevalence between farms close to the GNP, where there is greater chance for the sylvatic cycle to cause outbreaks, and farms located in the rest of the district, where pig to pig transmission is more likely to occur, were marginally significant. Ornithodoros spp. ticks were found in only 2 of 20 pig pens outside the GNP, and both pens had ticks testing positive for ASFV DNA. Interviews carried out among farmers indicated that biosecurity measures were mostly absent. Herd sizes were small with pigs kept in a free‐ranging husbandry system (65%). Only 1.6% of farmers slaughtered on their premises, but 51% acknowledged allowing visitors into their farms to purchase pigs. ASF outbreaks seemed to have a severe economic impact with nearly 36% of farmers ceasing pig farming for at least 1 year after a suspected ASF outbreak. This study provides the first evidence of the existence of a sylvatic cycle in Mozambique and confirms the presence of a permanent source of virus for the domestic pig value chain.     

A New Approach for Rapidly Assessing the Risk of Aujeszky's Disease Reintroduction into a Disease‐free Spanish Territory by Analysing the Movement of Live Pigs and Potential Contacts with Wild Boar

Aujeszky's disease (AD) causes significant economic losses in the Spanish pig sector due to import trade restrictions imposed by disease‐free countries. Most regions of Spain have achieved ‘low AD prevalence’ status as a result of an intensive national AD eradication programme involving vaccination and other measures. However, to achieve AD‐free status that would eliminate trade restrictions, vaccination must be stopped. For this final stage of eradication, up to date and reliable estimates of the risk of AD reintroduction are essential. Here, we propose an approach based on spatio‐temporal scan statistics that the assesses risk of AD reintroduction in a disease‐free territory by analysing the two most frequent risk pathways: movement of live domestic pigs and contact with wildlife reservoirs. The approach is illustrated using the case of Navarre, one of the first Spanish regions which plan to stop vaccination. Moreover, direct contacts among pig farms in Navarre were used to evaluate the potential spread of AD in the event of reintroduction. Areas at highest risk of AD reintroduction were in the southern part of the region during the second half of the year through pig movements and in the western and east‐central parts of Navarre through contact with wild boars. Northern Navarre, despite having the highest density of pig farms, seems to be at low risk of AD reintroduction. Analysing the network of pig movements within Navarre revealed distinct northern and southern compartments that may be used in preventive compartmentalization strategies to reduce potential risk of AD re‐infection in the scenario without vaccination. The approach described here may be extended to other regions and may be useful for guiding risk‐based measures that reduce the risk of AD re‐infection in a more cost‐effective manner. Such analysis in Spain may allow authorities to stop vaccination in the safest possible way.     

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.     

Clinical symptoms of African swine fever in domestic pig farms in the Republic of Korea, 2019

This study describes the clinical characteristics of the African swine fever (ASF) outbreaks in 14 domestic pig farms in the Republic of Korea. ASF outbreak was identified by farmers' notifications in 11 farms and by active surveillance in the remaining three. At the time of notification, farmers reported sudden death, abortion and anorexia in sows. Death was the primary symptom identified by farmers in fattener pigs. The number of animals exhibiting clinical symptoms did not exceed four heads at notification, and the number of asymptomatic virus positives was four heads per farm on average. As ASF virus was detected only in the same pig house (in a pen for fattener pigs) in each of 14 ASF outbreak farms, there has been no evidence of house‐to‐house viral spread within any of the ASF outbreak farms. This in turn supports our hypothesis that infection was successfully detected during its initial phase.     

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.     

A Cartographic Tool for Managing African Swine Fever in Eurasia: Mapping Wild Boar Distribution Based on the Quality of Available Habitats

The current African swine fever (ASF) epidemic in Eurasia represents a risk for the swine industry with devastating socio‐economic and political consequences. Wild boar appears to be a key factor in maintaining the disease in endemic areas (mainly the Russian Federation) and spreading the disease across borders, including within the European Union. To help predict and interpret the dynamics of ASF infection, we developed a standardized distribution map based on global land cover vegetation (GLOBCOVER) that quantifies the quality of available habitats (QAH) for wild boar across Eurasia as an indirect index for quantifying numbers of wild boar. QAHs were estimated using a seven‐level scale based on expert opinion and found to correlate closely with georeferenced presence of wild boar (n = 22 362): the highest wild boar densities (74.47%) were found in areas at the two highest QAH levels, while the lowest densities (5.66%) were found in areas at the lowest QAH levels. Mapping notifications from 2007 to 2016 onto the QAH map showed that in endemic areas, 60% of ASF notifications occurred in domestic pigs, mostly in agricultural landscapes (QAHs 1.75 and 1) containing low‐biosecurity domestic pig farms. In the EU, in contrast, 95% of ASF notifications occurred in wild boar, within natural landscapes (QAH 2). These results suggest that the QAH map can be a useful epi‐tool for defining risk scenarios and identifying potential travel corridors for ASF. This tool will help inform resource allocation decisions and improve prevention, control and surveillance of ASF and potentially of other diseases affecting swine and wild boar in Eurasia.     

Surveillance for African Swine Fever in Nigeria, 2006–2009

African swine fever (ASF) has had significant economic and social impact in Nigeria since 1997. However, there has been no effective national response to bring it under control. In this report, we confirm that ASF is still prevalent and widespread in Nigeria. Results from both serosurveillance and virological analyses indicated that ASF is present in most of the agro‐ecological zones of the country. Nine per cent (9%) of serum samples and 48% of tissue samples were positive for ASF virus antibody and genome, respectively. Areas with high pig‐related activities (marketing, consumption and farming) have higher prevalences compared with areas with less pig activities. Farm‐gate buyers, marketing systems and transport of untested pigs within the country assist with the circulation of the virus. Only by putting in place a comprehensive routine surveillance and testing system, reorganizing the market and transportation systems for pigs, implementing on‐farm bio‐security protocols and considering the option of compensation will it be possible to achieve a significant reduction in ASF prevalence in Nigeria.     

Spatio‐Temporal Dynamics of African Swine Fever Outbreaks in Nigeria, 2002–2007

African swine fever (ASF) was first introduced into Nigeria through Lagos state in 1997. The disease rapidly spread to Ogun state in 1998 and extended to the Niger Delta (Delta, Rivers and Akwa Ibom states) in the same year. In 1998, Kaduna, Plateau and Benue states all north of the country experienced ASF for the first time. Poor farm biosecurity, bad abattoir practices and extensive/free range pig farming systems led to extensive spread of the diseases to about 16 Nigerian states excluding the far northwest and north east. A total of 1036 field samples collected over a 6‐year period covering 19 Nigerian states were analysed during the period under review; 805 samples were PCR positive and 231 negative. Positive samples were detected in all three surveillance phases and from all agroecological zones across the country. For the first time since its incursion, ASF was identified in some states; Bauchi, Adamawa Taraba and Gombe with chances of control very slim and further spread of the virus northward envisaged. Outbreaks of the disease are now a perennial problem with an increasing disease burden in areas where high numbers of pigs are produced in the country. The National Veterinary Research Institute (NVRI), Vom, since 2002 investigated ASF based on tissue submissions and reports made by individuals, private & commercial farms and agricultural bodies. We present an analysis of geographical and temporal distribution of ASF in the country from 2002 to 2007 and a review of historic outbreaks since the first incursion. Risk factors and prospects for control are discussed.     

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.     

Epidemiological Characteristics of the 2002 Outbreak of Foot‐and‐Mouth Disease in The Republic of Korea

The Republic of Korea experienced a foot‐and‐mouth disease (FMD) outbreak during May–June 2002. The present study describes epidemiological characteristics of the 2002 FMD outbreak in Korea, including the pattern of the outbreak in both time and space, transmission routes among infected farms, and control measures. One of the notable features of the 2002 FMD epidemic in Korea was that the virus infected mostly pigs [15 of 16 infected premises (IPs)], despite the presence of other susceptible animals on infected and neighbouring farms. The epidemic showed temporal clustering at 8–9 day intervals, suggesting five generations of infection during the outbreak, and 13 of 16 (81.3%) IPs were located within a 10 km‐radius of the index case. The clinical signs that prompted notification of infection included vesicles around hooves and snouts. The age of lesions was significantly less among cases reported by farmers compared with veterinarians. The high awareness of farmers from an earlier FMD outbreak greatly helped the animal hygiene authority in efforts associated with disease control and eradication. The outbreak was eradicated within < 2 months as a result of the intensive control efforts of the animal hygiene authorities and the cooperation of the Korean people. Although the outbreak was a costly lesson for the Korean people, the experience gained will contribute to future efforts in the prevention and control of animal infectious diseases.     

Overcoming the challenges of pen‐side molecular diagnosis of African swine fever to support outbreak investigations under field conditions

African swine fever (ASF) is a devastating disease of pigs. Without a vaccine, early detection and rapid diagnosis of ASF is a crucial step towards effective disease control. In many countries where ASF is endemic, laboratory infrastructure including sampling and sample shipment is inadequate, and a rapid laboratory confirmation would require that the diagnosis is performed at regional laboratories close to the pig farms of concern, or even at the farm‐side. This study intended to evaluate measures including sample preparation methods, a dried‐down assay, and a portable, battery‐powered real‐time PCR instrument, to improve molecular diagnosis under field conditions. A simple dilution of blood samples, either in Phosphate‐buffered saline or a commercial buffer, worked similarly to beads‐based nucleic acid extraction using a magnet as the core equipment; the latter method did work as well for those samples with low viral load or high Ct values. The real‐time PCR assay using a Universal ProbeLibrary (UPL) probe tolerated suspected inhibitory substances present in the prepared samples better, whereas the dried‐down assay had a higher diagnostic sensitivity. Additionally, an inhibition control assay proved to be helpful in avoiding false negative results when interpreting negative results of samples that might be of low quality or with inadequate reduction in inhibitory substances. When tested with synthetic DNA standards, the portable instrument performed at a level approaching stationary thermocyclers. In summary, the developments of suitable sample preparation methods, robust and thermal‐stable real‐time PCR assays with inhibition control, and battery‐powered portable thermocyclers with middle‐throughput offer one way forward to provide rapid, reliable molecular diagnosis under challenging field conditions.     

Evaluation of Oral Bait Vaccine Efficacy Against Classical Swine Fever in Village Backyard Pig Farms in Bhutan

Control and eradication of classical swine fever (CSF) in countries with a high proportion of backyard holdings is a challenge. Conventional attenuated Chinese C‐strain vaccines, though safe and effective, are difficult to use in backyard farms due to various practical reasons. The aim of this study was to evaluate the efficacy of the CSF oral bait vaccine in village backyard pig farms and to assess the farmers' knowledge on CSF and motivation on using oral vaccines. The pigs were fed the bait by the farmers themselves; one bait was given on day 0, followed by second bait on the next day. Seventy‐three per cent (140 of 193 pigs) of vaccinated pigs had either a slight (2‐fold–3‐fold; 60 pigs) or significant (at least 4‐fold; 80 pigs) increase of the antibody titre against CSFV. A significant increase of the antibody titres was mainly observed in pigs with no pre‐vaccination titre (OR = 12, 95% CI = 4–40). The number of pigs with protective antibody titres (≥40) rose from 47 (24%) to 115 (60%) following vaccination. Only 30% of the farmers claimed to be familiar with CSF, although clinical signs they mentioned were rather unspecific and could relate to many other pig diseases. Most of the farmers claimed to be motivated to use oral vaccines if made available. The oral vaccine could be a substitute for the conventional attenuated CSF vaccines in areas where it is logistically difficult for veterinarians to visit. It may therefore be a useful tool to combat endemic CSF disease in regions where the disease continues to have a serious impact on the backyard farmers who depend on pig farming for their sustenance and livelihoods.