Isolation of Leishmania major from a Naturally Infected Vervet Monkey (Cercopithecus aethiops) Caught in Kiambu District, Kenya

Abstract

demic in several parts of Kenya. The current general situation and epidemiology of these 2 diseases suggest zoonoses and the existence of animal reservoirs. Different species of rodents are involved as reservoirs of L. major in different parts of the Old World. Through most of its distribution, gerbils, Tetera spp., are the principal reservoir hosts, and other rodents in Israel, Senegal, Ethiopia, and Saudi Arabia have also been implicated (Gunders et al., 1968, Transactions of the Royal Society of Tropical Medicine and Hygiene 62: 465; Ranque et al., 1974, Bulletin de la Societe de Pathologie Exotique 67: 167174; Elbihari et al., 1984, Annals of Tropical Medicine and Parasitology 78: 543-545). Occasionally, dogs have been found to be infected with L. major, which has recently been isolated in Egypt (Schnur et al., 1985, Transactions of the Royal Society of Tropical Medicine and Hygiene 79: 134-135) and Saudi Arabia (Peters et al., 1985, Transactions of the Royal Society of Tropical Medicine and Hygiene 79: 831-839). The presence of Leishmania major in Baringo District was reported in gerbils, Tetera nigricauda, and ground squirrels, Xerus rutilus, by Heisch (1963, East African Medical Journal 40: 359362), and in addition, Beach et al. (1984, Transactions of the Royal Society of Tropical Medicine and Hygiene 78: 747-751) isolated a strain of L. major from Phlebotomus dubosqi in the same region. Recent studies have also shown that several other species of rodents harbour natural infections of L. major and human cases have also been reported in Baringo District (Githure et al., 1986, Annals of Tropical Medicine and Parasitology 80: 501-507; Muigai et al., 1987, Transactions of the Royal Society of Tropical Medicine and Hygiene [in press]). Old World nonhuman primates, such as Sykes monkeys, vervet monkeys, and baboons, have been shown to be susceptible to experimental infection with L. donovani (Githure et al., 1986, Transactions of the Royal Society of Tropical Medicine and Hygiene 80: 575-576). Recent experiments show that Old World monkeys are also susceptible to experimental infection with L. major. Our study was therefore designed to determine whether or not monkeys caught in the wild harbour any leishmanial parasites. Three species of Old World primates were trapped using locally made traps and brought to the Institute of Primate Research, Karen, where they were quarantined before introducing them into the colony. The 40 study animals included 30 vervet monkeys (Cercopithecus aethiops), 5 Sykes monkeys (Cercopithecus mitis), and 5 baboons (Papio cynocephalus). Of these 40 animals, 28 vervet monkeys came from Thika in the Kiambu District. The rest came from Kibwezi