African Swine Fever

return to Swine Manual index


A highly contagious, viral disease with signs, lesions and other features that closely resemble swine fever (CSF). The disease is exotic to the US.


African swine fever (ASF) occurs naturally in wild, feral and domestic swine (Suidae). At present, ASF does not occur in the western hemisphere. It is endemic in several African countries and an outbreak of the disease has been occurring across several countries in Central Asia since 2007. Distribution among countries changes, depending on new infections, re-infections and the success of eradication programs.

Historical information

African swine fever first was described in Africa in 1921. It soon was endemic in eight African countries. In 1957, the disease occurred in Portugal, the first non-African country to be infected. Over a 28-year period, ASF spread to eight European countries, Brazil, Cuba, Haiti and the Dominican Republic.

In some countries, repeated outbreaks have discouraged eradication efforts. In many other countries, eradication efforts have been successful. Prohibiting importation of swine and pork from infected countries, and eliminating or regulating the practice of waste-food feeding to pigs are fundamental to most successful eradication programs. Several features of ASF, plus the high cost of eradication, make worldwide eradication unlikely. The United States has never experienced an outbreak although ASF has occurred several times in nearby Caribbean islands.