Exploring the hurdles that remain for control of African swine fever in smallholder farming settings

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.

Semiquantitative Risk Evaluation Reveals Drivers of African Swine Fever Virus Transmission in Smallholder Pig Farms and Gaps in Biosecurity, Tanzania

African swine fever (ASF) has remained persistent in Tanzania since the early 2000s. Between 2020 and 2021, pig farms in twelve districts in Tanzania were infected with ASF, and ≥4,804 pigs reportedly died directly due to the disease with disruption to livelihoods. We conducted semiquantitative field investigations and rapid risk assessment (RRA) to understand the risk factors and drivers of ASF virus (ASFV) amplification and transmission in smallholder pig farms, and determine the gaps in biosecurity through hazard profiling, focus group discussions and expert opinion. Outbreaks were connected by road and aligned along the pig product value chain and reported in the northern, central, and southern parts of Tanzania. The patterns of outbreaks and impacts differed among districts, but cases of ASF appeared to be self-limiting following significant mortality of pigs in farms. Movement of infected pigs, movement of contaminated pig products, and fomites associated with service providers, vehicles, and equipment, as well as the inadvertent risks associated with movements of animal health practitioners, visitors, and scavengers were the riskiest pathways to introduce ASFV into smallholder pig farms. Identified drivers and facilitators of risk of ASFV infection in smallholder pig farms were traders in whole pigs, middlemen, pig farmers, transporters, unauthorized animal health service providers, and traders in pork. All identified pig groups were susceptible to ASFV, particularly shared adult boars, pregnant and lactating sows, and other adult females. The risk of ASF for smallholder pig farms in Tanzania remains very high based on a systematic risk classification. The majority of the farms had poor biosecurity and no single farm implemented all identified biosecurity measures. Risky practices and breaches of biosecurity in the pig value chain in Tanzania are profit driven and are extremely difficult to change. Behavioural change communication must target identified drivers of infections, attitudes, and practices.

2023 International African Swine Fever Workshop: Critical Issues That Need to Be Addressed for ASF Control

The 2023 International African Swine Fever Workshop (IASFW) took place in Beijing, China, on 18-20 September 2023. It was jointly organized by the U.S.-China Center for Animal Health (USCCAH) at Kansas State University (KSU) and the Chinese Veterinary Drug Association (CVDA) and sponsored by the United States Department of Agriculture Foreign Agricultural Service (USDA-FAS), Harbin Veterinary Research Institute, and Zoetis Inc. The objective of this workshop was to provide a platform for ASF researchers around the world to unite and share their knowledge and expertise on ASF control and prevention. A total of 24 outstanding ASF research scientists and experts from 10 countries attended this meeting. The workshop included presentations on current ASF research, opportunities for scientific collaboration, and discussions of lessons and experiences learned from China/Asia, Africa, and Europe. This article summarizes the meeting highlights and presents some critical issues that need to be addressed for ASF control and prevention in the future.

An approach for embedding behavioural science in antimicrobial resistance One Health research

Antimicrobial Resistance (AMR) is a global health emergency that threatens modern medicine and incurs great cost to human health. The World Health Organization as part of a quadripartite joint initiative with the Food and Agriculture Organization of the United Nations, World Organisation for Animal Health, and United Nations Environment Programme, has recently published a One Health Priority Research Agenda for AMR. In this article we present a multidisciplinary approach, proposed by behavioural science experts, One Health experts and AMR experts to support the implementation of the Priority Research Agenda. We review, using specific examples of complex interventions designed to tackle AMR in which behavioural science has been embedded, five main steps: Define - what behaviours are a priority in each context; Diagnose - What are the barriers and enablers to the behaviours prioritised? Design - what interventions exist and what new or enhanced interventions could work to tackle the barriers identified? and, Implement and Evaluate the intervention(s). The approach presented will be useful for funders and researchers who wish to incorporate methods, frameworks and insights from the behavioural sciences into research plans, proposals and protocols in relation to a multisectoral One Health agenda and produce findings that are more relevant to policymakers.

Understanding the interface between European wild boar (Sus scrofa) and domestic pigs (Sus scrofa domesticus) in Sweden through a questionnaire study

BACKGROUND

In recent years, the wildlife/livestock interface has attracted increased attention due to disease transmission between wild and domestic animal populations. The ongoing spread of African swine fever (ASF) in European wild boar (Sus scrofa) emphasize the need for further understanding of the wildlife/livestock interface to prevent disease spill-over between the wild and domestic populations. Although wild boar may also act as a potential source for other infectious disease agents, ASF is currently the most severe threat from wild boar to domestic pigs. To gather information on the wild boar situation at commercial pig producing farms in Sweden, a digital questionnaire survey was distributed through the animal health services.

RESULTS

Most pigs produced for commercial purposes in Sweden are raised without outdoor access. Of the 211 responding pig producers, 80% saw wild boar or signs of wild boar activity in the vicinity of their farm at least once during the year. Observations were significantly correlated with geographical region, but there was no correlation between farm characteristics (farm size, main type of production, outdoor access) and observed wild boar presence or proximity. However, a reported higher frequency of wild boar observations was positively correlated with the observations being made in closer proximity to the farm. Hunting and strategic baiting were the most common mitigation strategies used to keep wild boar at bay. Of the 14 farms raising pigs with outdoor access, 12 responded that these pigs could be raised solely indoors if needed. Pigs with outdoor access are required to be fenced in, but double fencing in these outdoor pig enclosures was not practiced by all. A perimeter fence surrounding any type of pig farm was very rare. More than half of the producers that grew crops with intended use for pigs reported crop damage by wild boar.

CONCLUSION

This study shows that although pigs raised for commercial purposes in Sweden are, to a large extent, kept indoors the potential for indirect contact with wild boar exists and must be considered. Variable local situations regarding wild boar abundance may require an adaptive approach regarding biosecurity efforts.

Limitations and opportunities of smallholders' practical knowledge when dealing with pig health issues in northern Uganda

Pig production has a short history in Uganda. The majority of pigs are kept by smallholder farmers in rural areas where access to veterinary services is limited, and pig keeping has been suggested as a potential pathway out of poverty for smallholders. Previous research has identified the disease of African swine fever (ASF) as a major threat, causing high mortalities in pigs. With no available cure or vaccine, the only option is to implement biosecurity measures, i.e. strategies that prevent the spread of ASF. This paper draws on data from four months of ethnographic fieldwork in rural northern Uganda. Combining methods of participant observation, semi-structured interviews, focus group discussions and a survey, the aim was to improve understanding of smallholders' perceptions and responses to pig health issues such as ASF. Applying the concept of practical knowledge, this paper analyses the potential and limitations of smallholders' practice-based knowledge as a means of dealing with pig health issues. The results show that while pigs were appreciated locally for providing an income, many informants found it difficult to deal with pig diseases effectively. Consequently, informants commonly expressed a need for other kinds of knowledge in their pig production, indicating that veterinary advice can play an important role in reducing the negative impact of pig health issues. For animal health provision to have relevance in this context, however, veterinary practitioners must pay close attention to smallholders' priorities and ways of knowing in their livestock keeping. Results further show that pig health issues made some informants abandon pig production altogether. To enhance the potential of pig production as a poverty mitigation strategy in Uganda, research and policy need to focus on ways of bettering general conditions for smallholder pig keeping, including improving the quality of and access to veterinary services in rural areas.

Innovative Research Offers New Hope for Managing African Swine Fever Better in Resource-Limited Smallholder Farming Settings: A Timely Update

African swine fever (ASF) in domestic pigs has, since its discovery in Africa more than a century ago, been associated with subsistence pig keeping with low levels of biosecurity. Likewise, smallholder and backyard pig farming in resource-limited settings have been notably affected during the ongoing epidemic in Eastern Europe, Asia, the Pacific, and Caribbean regions. Many challenges to managing ASF in such settings have been identified in the ongoing as well as previous epidemics. Consistent implementation of biosecurity at all nodes in the value chain remains most important for controlling and preventing ASF. Recent research from Asia, Africa, and Europe has provided science-based information that can be of value in overcoming some of the hurdles faced for implementing biosecurity in resource-limited contexts. In this narrative review we examine a selection of these studies elucidating innovative solutions such as shorter boiling times for inactivating ASF virus in swill, participatory planning of interventions for risk mitigation for ASF, better understanding of smallholder pig-keeper perceptions and constraints, modified culling, and safe alternatives for disposal of carcasses of pigs that have died of ASF. The aim of the review is to increase acceptance and implementation of science-based approaches that increase the feasibility of managing, and the possibility to prevent, ASF in resource-limited settings. This could contribute to protecting hundreds of thousands of livelihoods that depend upon pigs and enable small-scale pig production to reach its full potential for poverty alleviation and food security.

Community engagement strengthens pig disease knowledge and passive surveillance in Timor-Leste

Smallholder pig production in Timor-Leste is culturally and economically important for most households. However, regular and ongoing disease surveillance and pig husbandry training for farmers are limited. This article describes collaborative social and diagnostic research followed by a pilot community engagement program to improve farmer and technician knowledge, skills, and working relationships. There were three phases: (1) A qualitative study in 2020 to explore the experiences and knowledge of 133 pig farmers, 6 village leaders, and 16 district veterinary technicians on pig diseases and reporting, treatment methods, and access to information or assistance. (2) A pilot community engagement program in 3 villages in 2021 with the diagnostic investigation with samples analyzed from 27 dead pigs, and (3) Evaluation of community engagement and training outcomes. Results of the qualitative study revealed limited reporting of sick or dead pigs by farmers to veterinary technicians due to a lack of trust in the veterinary diagnostic system. Most technicians lacked experience with sampling or post-mortems so diagnostic training was undertaken for the pilot disease investigation. Evaluation results showed improved knowledge, motivation, and confidence of government staff and farmers. The credibility of veterinary technicians improved and gave them more confidence to work with communities. Farmers felt supported because all aspects of pig husbandry were addressed, and they were more willing to report dead or sick pigs. The project indicates that improved passive disease surveillance can be achieved by engaging communities in smallholder pig farming in Timor-Leste. Further research and testing of the approach in other districts and countries is recommended.

Review of the Pig-Adapted African Swine Fever Viruses in and Outside Africa

The region in eastern, central and southern Africa (ECSA) where African swine fever (ASF) originated in a sylvatic cycle is home to all the p72 genotypes of ASF virus identified so far. While 20 of the 24 genotypes have been isolated from outbreaks in domestic pigs in the region, only five of the genotypes (I, II, VIII, IX, X) have an extended field presence associated with domestic pigs. Of the genotypes that appear to be strongly adapted to domestic pigs, two have spread beyond the African continent and have been the focus of efforts to develop vaccines against ASF. Most of the experimental ASF vaccines described do not protect against a wider spectrum of viruses and may be less useful in the event of incursions of different strains or where multiple genotypes co-exist. The other three pig-adapted strains that are currently restricted to the ECSA region might spread, and priority should be given to understanding not only the genetic and antigenic characteristics of these viruses but also their history. We review historic and current knowledge of the distribution of these five virus genotypes, and note that as was the case for genotype II, some pig-associated viruses have the propensity for geographical range expansion. These features are valuable for prioritizing vaccine-development efforts to ensure a swift response to virus escape. However, whilst ASF vaccines are critical for high-production systems, global food security relies on parallel efforts to improve biosecurity and pig production in Africa and on continued ASFV surveillance and characterisation in the ECSA region.

Analysis of the drivers of ASF introduction into the officially approved pig compartments in South Africa and implications for the revision of biosecurity standards

BACKGROUND

While African Swine Fever (ASF) virus has historically circulated in wild pigs and in Ornithodoros ticks in parts of South Africa, the virus has spread among domestic pigs throughout the country since 2019. South Africa's compartment system has been used as a mainstay approach to protecting the swine industry in the face of ASF. However, in 2020, two compartments broke down with ASF. The objectives of this study are to investigate the drivers for ASF introduction into the compartments, to categorize compartments by risk of ASF introduction, and to make corresponding recommendations. The relevance of risk factors for ASF introduction for each compartment were investigated among veterinarians and farm managers. The analysis of risk factors weighted according to an expert elicitation were used to categorize compartments into risk levels.

RESULTS

Drivers of disease related to human behaviors and to domestic pig management are perceived by farm managers and veterinarians of the compartments to be critical for ASF introduction into compartments in South Africa. Twenty-four units were categorized as high risk, forty-seven as medium risk, and twenty-four as low risk. "Insufficient boot and clothing biosecurity by animal health personnel" was identified as a relevant risk factor in all high risk units. Other prominent risk factors were "insufficient boot and clothing biosecurity by external people," "underreporting of suspect ASF cases," "improper hunting/ culling of wild suids inside the compartment," "un-tested introductions into the herd," and "entry and contact with free-roaming pigs." The roles of wild pigs and competent vectors are considered minimal. There is a need for revision of the compartment standards and training of compartment personnel on the standards. The major gaps identified in the standards were absence of a monitoring programme to assess biosecurity implementation and suboptimal surveillance testing and audit strategies.

CONCLUSIONS

The results of our study confirm that ASF is increasingly an anthropogenic problem. Updating the compartment standards and addressing gaps in the knowledge of compartment personnel on ASF are most critical. To enhance compliance with biosecurity measures and thus control the disease, close engagement with all stakeholders linked to the compartments is needed.