June 30, 2025
North Rhine-Westphalia, Germany variant of ASF different from other German variants, investigation found
As part of its virological investigation into the outbreak of African swine fever (ASF) in North Rhine-Westphalia, Germany, the Friedrich-Loeffler-Institut has determined the complete genome sequence of blood and tissue samples taken from wild boars.
A direct comparison with ASF viruses that have previously been sequenced in Germany shows that the North Rhine-Westphalian variant differs significantly from the West German variants previously identified in Hesse, Rhineland-Palatinate and Baden-Württemberg, as well as the variants from the eastern federal states of Saxony, Brandenburg and Mecklenburg-Western Pomerania.
An international comparison with published genome data reveals a high degree of similarity with ASF viruses from the Italian region of Calabria. These Italian variants exhibit specific changes that have also been found in the new North Rhine-Westphalian variant and distinguish it clearly from other previously known ASF viruses.
A recent study in Genome Biology and Evolution, published by Oxford University Press, found that the ASF virus, currently circulating in Europe, is not the result of a recent introduction. Instead, the virus has been present in the region since 2007 and its dramatic spread appears to be driven largely by people within Europe traveling longer distances.
Initially limited to the sub-Saharan African region, the virus (specifically genotype II) spread globally and is now a major concern in Africa, Europe, Asia, the Pacific, and more recently, the Caribbean. In 2024, the World Organization for Animal Health reported ASF outbreaks in seven European countries, with over one million pigs lost since 2022.
The researchers analysed 10 samples from domestic pigs and wild boar, collected between July 26, 2016, and August 23, 2019, as part of the State Food and Veterinary Service of the Republic of Lithuania's surveillance activities in Lithuania. From these samples, they generated complete genome sequences of ASF virus. These new sequences expanded the existing dataset of the ASF virus genomes genotype II and were used to study of the spread of the virus across the European continent.
"African swine fever virus continues to threaten domestic pig and wild boar populations in Europe," said the paper's lead author, Christopher Netherton. "Each viral genome we sequence helps to deepen our understanding of the virus's circulation dynamics."
- National Hog Farmer
