Swine fever in South Africa

Abstract

1. It is believed that various outbreaks of swine fever in South Africa have probably occurred since 1900. The disease in domestic pigs produced by the blood of warthogs resembled the European disease. Probably in swine fever, as in many virus diseases, more than one "strain" of virus exists. 2. Reference was made to the virulent nature of this disease in South Africa, and the fact that it does not progress as an enzootic as in European countries. A number of recovered animals harboured the virus for long periods. 3. It is quite likely that the virus in South Africa may also be maintained in a limited number of warthogs in certain areas of Northern Transvaal where domestic pigs occasionally become infected. That may explain the intermittent incidence of this disease in South Africa. 4. From the investigations carried out it would appear that the following may occur in South Africa: (a) Uncomplicated very acute form of swine fever without manifestations of "boutons", diphtheresis, hepatization of the lungs, etc. (b) Swine fever possibly complicated by such secondary infections as S. cholerae suis and B. suisepticus. (c) A septicaemic type of S. cholerae suis infection in an enzootic form and probably associated with such predisposing causes as bad hygiene, overcrowding, defective feeding, etc. 5. A description of the main pathological changes is given, and the value of the histological examination of organs for diagnostic purposes is discussed.