African Swine Fever Outbreak: What It Means for Europe's Farms
"Tracing the virus's path and understanding its impact on the global pork industry."
African swine fever (ASF) is a highly contagious and deadly viral disease affecting domestic and wild pigs. It poses a significant threat to the pork industry and has caused considerable economic damage in affected regions.
In September 2018, ASF was detected in wild boars in Belgium, marking a westward expansion of the virus within Europe. This discovery raised concerns about the potential spread of the disease to other countries and the subsequent impact on pig farms and related industries.
A recent study investigated the genetic characteristics of the ASF virus found in Belgium to determine its origin and track its potential spread. By analyzing the virus's genetic code, researchers aimed to understand the transmission pathways and inform strategies for controlling the outbreak.
European ASF Surveillance
USDA’s Animal and Plant Health Inspection Service (APHIS) maintains an African swine fever (ASF) and classical swine fever (CSF) dashboard with national- and State-level surveillance views. APHIS says the data support disease detection, outbreak preparedness, and claims of disease status. WOAH’s January 2026 report recorded one new ASF event in Asia, updates to ongoing events in one African, two Asian, and thirteen European countries, and no new outbreaks in the Americas or Oceania. The same report recorded twelve new outbreaks in domestic pigs and around 724 in another reported animal category.
Detection and Standardization
ASF is a highly contagious disease of wild and domestic suids, with high rates of morbidity and mortality, and it is a notifiable disease under WOAH standards. Current detection work focuses on validated diagnostic methods and standardized procedures. The Community Reference Laboratory for African Swine Fever publishes EURL standard operating procedures for ASF diagnostic methods, including procedures for interpreting results. WOAH, FAO, and other partners have also issued updated guidance for countries affected by or at risk of ASF incursion.
A Century of Spread
ASF was first described in Kenya in 1921, according to USDA and a 2026 comprehensive review. USDA reports that the disease remained on the African continent until 1957, after spreading through several sub-Saharan African countries. The review published in June 2026 describes ASF as a highly contagious and often fatal disease affecting domestic pigs and wild boars. It also reports that ASF has since spread globally, causing significant economic losses and threatening food security.
Unraveling the Origin: Genetic Fingerprints of the ASF Virus
The study revealed that the ASF virus strain found in Belgium belongs to genotype II, a group that includes viruses circulating in both Eurasia and Southern Africa. Further genetic analysis pinpointed the virus's closest relatives to strains previously isolated in Ukraine, Belarus, Estonia, and European Russia.
- Genotype II: The ASF virus found in Belgium belongs to a widespread and concerning group.
- Eastern European Connection: The virus shares genetic similarities with strains from Ukraine, Belarus, Estonia, and Russia.
- Genetic Marker: A specific insertion in the virus's genetic code links it to a potential origin in Eastern Europe.
Genomes, Vectors, and Vaccines
Recent research examines several parts of ASF epidemiology and control. An expert assessment studied the capacity of blood-feeding arthropods to transmit ASF virus in metropolitan France. Genome-sequencing work compared Eastern European sequences and identified three differences found exclusively in the ASFV Moldova 2017/1 genome sequence. Vaccine research includes live-attenuated, subunit, and other platforms, but reported challenges include reversion to virulence, suboptimal protection, and insufficient cross-protection.
Limits of Molecular Tracking
Genotyping the p72 and IGR loci is compatible with the current state of the art for ASFV molecular epidemiology, but published analyses identify intrinsic limitations. This matters because molecular typing may not fully resolve transmission histories or distinguish all epidemiologically relevant differences. A 2020 review describes ASF as a viral hemorrhagic disease with exceptionally high lethality in domestic pigs and Eurasian wild boar and notes its unprecedented distribution across several European and Asian countries. Other reviews emphasize that infection in ticks and wild swine, together with global pork trade, contributes to the disease’s spread and persistence.
ASF and CSF Are Distinct
African swine fever and classical swine fever have similar names, but they are distinct diseases. A comparative review notes that ASF was once thought to be caused by the same virus as CSF before Montgomery described ASF as an independent disease entity in Kenya. Recent evidence also identifies genotype I/II recombinant ASF virus in the Asia-Pacific region as a significant shift in ASF molecular epidemiology. Research on attenuated ASFV strains has demonstrated protection against a homologous virulent virus, while other reviewed material describes ASF as an acute hemorrhagic disease of pigs caused by ASFV.
Implications and Future Directions
The emergence of ASF in Belgium highlights the ongoing threat posed by this virus to the European pork industry. The study's findings underscore the importance of strict biosecurity measures and surveillance programs to prevent further spread.
Forecasting Global Dynamics
A 2026 study presents ASF as a persistent and escalating threat to global swine production. It analyzes global spatiotemporal dynamics from 1996 to 2025 using an integrated framework that combines multi-distance spatial analysis with advanced time-series forecasting. The framework uses a dataset containing 57,253 outbreak records. This approach points toward more systematic analysis of where ASF has occurred and how its patterns may develop.
Markets, Smallholders, and Regulation
After ASF reached China from Europe in 2018, the virus spread throughout the country and dramatically reduced China’s pork supplies, according to a USDA Economic Research Service report. The report examines how those effects changed China’s pork market and increased demand for imported pork from exporting countries. In lower-income countries, ASF outbreaks have occurred mainly among smallholder and village pigs. Managing outbreaks also involves legal and regulatory frameworks intended to control spread and mitigate economic impacts, as described in a case study of Lipa City.
Understanding the virus's transmission pathways is crucial for implementing effective control strategies. This includes monitoring wild boar populations, controlling animal movement, and ensuring proper hygiene practices on pig farms.
Future research should focus on whole-genome sequencing to gain a more detailed understanding of the virus's evolution and transmission dynamics. This information will be critical for developing targeted interventions and mitigating the impact of future outbreaks.