African Swine Fever (ASF) virus is a highly contagious Asfivirus that can cause serious disease and death in domestic and feral swine. The disease originated in Africa, then spread to Europe (2007) and Asia (2018). In 2021, the disease was detected in the Dominican Republic and Haiti, marking the first time the disease was diagnosed in the western hemisphere in 40 years.
ASFV is transmitted directly between pigs or indirectly via Ornithodoros ticks, ingestion of infected meat, or fomites. Meat from infected animals can remain infectious for up to 5 months.
After exposure, the incubation period is between 3-19 days. In the peracute form, sudden death may be observed. In the acute form, pigs demonstrate high fever, vomiting, diarrhea, abortion, and mortality (up to 100%). Less virulent subacute or chronic forms are often seen with less intense symptoms and lower mortality. A small number of animals can become lifelong carriers. No vaccine or treatment for this disease exists. The disease does not infect humans and poses no food safety threat.
International travelers should understand the risk of bringing ASF into the US, declare items and farm visits to US Customs, and avoid farms or locations with pigs for at least 5 days upon return.