ASFV

African swine fever virus (ASFV) is a large, enveloped double-stranded DNA virus that causes African swine fever (ASF) in domestic pigs and wild suids. It belongs to the family Asfarviridae and the genus Asfivirus. ASFV is the type species of its genus. Humans are not susceptible to infection, and the virus poses a major threat to pig production and animal health.

The ASFV genome is linear double-stranded DNA of about 170 to 190 kilobases and encodes more than 150 proteins. The virion is a large icosahedral particle, roughly 200 nanometers in diameter, with a protective envelope. Replication occurs in the cytoplasm and involves formation of viral factories. The virus exhibits substantial genetic diversity, with several genotypes; genotype II is responsible for most current outbreaks in Europe and Asia.

Transmission occurs through direct contact with infected animals, indirect contact via contaminated fomites, and ingestion of infected pig products. In some regions, soft ticks of the Ornithodoros genus serve as a natural reservoir. Wild boar populations help maintain the virus in the environment. The disease has spread from sub-Saharan Africa to Europe, the Caribbean, Asia, and parts of the Americas. ASF is a reportable disease in many countries and to the World Organisation for Animal Health (WOAH).

Clinical signs include fever, depression, loss of appetite, weakness, facial swelling, and petechial hemorrhages. Domestic pigs often die within 7 to 14 days; survivors may become carriers. Reproductive failure can occur in sows. There is no widely available vaccine or treatment; control relies on strict biosecurity, rapid diagnosis, movement controls, culling of infected and at-risk animals, and proper disposal of carcasses. Ongoing research seeks safe and effective vaccines.