African swine fever (ASF) is a highly lethal viral haemorrhagic fever of domestic pigs for which there is no vaccine. First described from Kenya in 1921, it was subsequently found to exist in most countries in southern and eastern Africa, where ASF virus is maintained in an ancient sylvatic cycle involving warthogs (Phacochoerus aethiopicus) and soft-shelled eyeless ticks of the Ornithodoros moubata complex. In a limited area in central Africa, a cycle in domestic pigs, which may involve ticks, has been documented. Spread of ASF to Europe from Africa in 1957 and 1959 focused attention on the devastating effects of the disease and the difficulties of control and eradication. ASF was apparently unknown in West Africa until a burgeoning pig industry inCameroon was virtually destroyed in 1982, but it has emerged that outbreaks occurred in Nigeria in 1973, and that the disease is endemic in Guinea Bissau, Senegal and the Cape Verde Republic, in which countries it was first rumoured to occur between 1958 and 1960. It is possible that previous occurrence of ASF in those countries escaped notice. In 1996, a severe outbreak of ASF occurred in Cote d'Ivoire. Although eradication was apparently accomplished by early 1997, ASF was reported for the first time in Benin, Togo and Nigeria in October 1997, and In October 1999 in Ghana.
展开▼
