AFRICAN SWINE FEVER IN MADAGASCAR: EPIDEMIOLOGICAL ASSESSMENT OF THE RECENT EPIZOOTIC

FAO, Animal Production and Health Division (AGA), Infectious Disease Group, Via delle Terme di Caracalla, 00100, Rome, Italy Since 1997, a highly contagious disease affe cts the swine population of Madagascar. Initially described as an acute, febrile, and hemorrhagic disease and designated as the Classical Swine Fever (CSF), a viral disease present in Madagascar since 1965, the spread of this epizootic continued in spite o f a vaccination campaign. The field data collected in 1999 showed animal losses of higher than 60 %. Pork is a significant element of the Malagasy culinary culture and improved porcine breeding had developed over the last few years. Material, Methods, and Results In December 1998, samples were collected and dispatched to a reference laboratory. ELISA antigen, isolation on cell cultures, experimental reproduction on naive animals, Polymerase -Chain -Reaction (PCR), sequencing and serology made it possibl e to diagnose, for the first time in Madagascar, the African Swine Fever (ASF). Data analyzed in 1999 showed an ELISA antigen rate of 14% (n=340) ; a PCR rate of 62% (n=72) and a serological positivity rate of 4% (n=1042, Blocking -ELISA test). It appeared that the virus was widespread: the major part of the Island was contaminated. The analyses of serums collected in 1996 and 1997 were all negative.