A CANINE-DISTEMPER VIRUS EPIDEMIC IN SERENGETI LIONS (PANTHERA LEO)

CANINE distemper virus (CDV) is thought to have caused several fatal e pidemics in canids within the Serengeti-Mara ecosystem of East Africa, affecting silver-backedjackals (Canis mesomelas) and bat-cared foxes (Otocyon megalotis) in 1978 (ref. 1), and African wild dogs (Lycaon pi ctus) in 1991 (refs 2, 3). The large, closely monitored Serengeti lion population(4,5) was not affected in these epidemics. However, an epid emic caused by a morbillivirus closely related to CDV emerged abruptly in the lion population of the Serengeti National Pack, Tanzania, in e arly 1994, resulting in fatal neurological disease characterized by gr and mal seizures and myoclonus; the lions that died had encephalitis a nd pneumonia. Here we report the identification of CDV from these lion s, and the close phylogenetic relationship between CDV isolates from l ions and domestic dogs. By August 1994, 85% of the Serengeti lion popu lation had anti-CDV antibodies, and the epidemic spread north to lions in the Maasai Mara National reserve, Kenya, and uncounted hyaenas, ba t-eared foxes, and leopards were also affected.