Oxford, June 4, 2025 — A newly published study in Genome Biology and Evolution, by Oxford University Press, reveals that the African Swine Fever Virus (ASFV) currently spreading across Europe is not the result of a recent introduction. Instead, genomic evidence shows the virus has been circulating in the region since 2007, with its dramatic recent expansion likely driven by increased human travel across longer distances within Europe.
African Swine Fever is a devastating hemorrhagic disease affecting domestic pigs and wild boars. Caused by a highly virulent DNA virus, ASFV leads to high mortality and severe economic consequences. According to the Food and Agriculture Organization, the disease has caused around $2.1 billion in direct losses globally over the past 17 years. Its impact is particularly severe on small and medium-sized pig farms, reshaping agricultural markets worldwide, including in China. Despite extensive research, there is still no widely available vaccine against ASF.
Originally confined to sub-Saharan Africa, ASFV genotype II has since spread globally, with outbreaks reported across Africa, Asia, the Pacific, Europe, and more recently, the Caribbean. In 2024, the World Organization for Animal Health documented outbreaks in seven European countries, with over one million pigs culled since 2022.
Genomic Evidence Traces ASFV’s European History
The study analyzed 10 ASFV samples collected from both domestic pigs and wild boars in Lithuania between July 2016 and August 2019. Conducted by researchers in collaboration with the State Food and Veterinary Service of Lithuania, the study produced complete genome sequences and compared them with global ASFV datasets.
Their findings reveal that the current European strains of ASFV genotype II share a common ancestor with African strains but show no signs of recent cross-continental transmission. Instead, the virus appears to have persisted and evolved locally in Europe for over a decade. The genomic data further point to Poland, Lithuania, Ukraine, and Germany as key players in the virus’s regional spread.
“Our analysis suggests that long-distance human movements within Europe are a major factor in the virus’s continued expansion,” explained lead author Christopher Netherton. “Each genome we sequence adds another piece to the puzzle, helping us better understand how the virus is circulating.”
Ongoing Threat to Livestock and Agriculture
ASFV remains one of the most pressing threats to pig populations worldwide. With no cure or effective vaccine, early detection and biosecurity remain essential tools in limiting its spread. The study's insights into viral transmission routes and its longstanding presence in Europe may aid future policy decisions and control strategies.
The paper, Exploiting viral DNA genomes to explore the dispersal history of African swine fever genotype II lineages in Europe, was authored by Gambaro et al. and is available in the journal Genome Biology and Evolution.
