Taiwan, which was officially certified as “free of swine fever” by the World Organisation for Animal Health (WOAH) in May this year, has reported its first positive case of African swine fever (ASF). The case was confirmed on October 22 at a pig farm in Wuqi, Taichung, where a dead pig tested positive, sparking widespread concern. ASF has long plagued livestock industries worldwide and is distinct from classical swine fever (CSF), also known as hog cholera. Recently, scientists have successfully bred pigs resistant to CSF, with hopes of applying similar techniques to other deadly viral diseases.
According to The Guardian, while CSF was eradicated in the UK in 1966, outbreaks have still occurred sporadically, with devastating effects on farmers and livestock. Helen Crooke, Deputy Head of Mammalian Virology at the UK Animal and Plant Health Agency (APHA), noted that CSF outbreaks have historically caused severe economic and emotional damage to the farming community, including the UK outbreak 25 years ago.
At the Roslin Institute, University of Edinburgh, scientists used gene-editing to modify a gene responsible for producing the “DNAJC14” protein, which plays a key role in pestiviruses’ replication once inside cells. In experiments, four genetically edited pigs were exposed to CSF alongside four unedited pigs. After a week, the unedited pigs displayed severe symptoms and high viral loads, while the gene-edited pigs remained completely healthy with no signs of infection. The results have been published in Trends in Biotechnology. Researchers are now exploring whether similar gene-editing techniques could confer resistance in other livestock, such as cattle and sheep.
Dr. Emily Clark from the European Molecular Biology Laboratory (EMBL) emphasized that this research could help produce healthier animals, reduce losses for farmers in regions affected by swine fever, and represents a major step forward in using genomics to enhance livestock disease resistance.
African Swine Fever vs. Classical Swine Fever
Both ASF and CSF are highly contagious viral diseases affecting pigs, but they are caused by different viruses. ASF, first identified in Kenya in 1921, is a DNA virus from the Asfarviridae family, while CSF is an RNA virus from the Flaviviridae family. Symptoms are similar, including high fever and systemic bleeding, but ASF can be distinguished by significantly enlarged spleens—2–3 times normal size—and spotted kidney bleeding resembling “turkey eggs.”
Currently, there is no effective vaccine for ASF. If the virus spreads in Taiwan, it could lead to high pig mortality rates and severe losses for the domestic pig farming industry.
