The first reported outbreak occurred in Bandundu Province in present-day DR Congo in 1936-1937 and the second in Nampula Province of Northern Mozambique in 1981.
Det första rapporterade utbrottet var i Bandundu-provinsen i nuvarande Kongo-Kinshasa 1936-1937 och det andra i Nampula-provinsen i norra Moçambique 1981.