Graham E. Kemp

ISOLATION OF VIRUSES FROM WILD MAMMALS IN WEST AFRICA, 1966-1970

During the 5-year period 1966–1970, a total of 7497 wild mammals of at least 101 different species were collected from 36 locations in Nigeria, Dahomey, and Togo and sampled for virus. The collections were made in five ecologically distinct vegetative zones: high forest, Guinea, Sudan, and Sahel woodland, and the Jos Plateau. Sixteen different virus types, represented by 83 isolates, were recovered, as follows: Arumowot (6 isolates), Bhanja (2), bluetongue type 7 (1), Chandipura (1), Congo (2), Dakar bat (3), Dugbe (1), IbAn 17143 (1), IbAn 33709 (1), Lebombo (1), Mokola (4), poxvirus IbAn 34325 (1), Semliki Forest (1), SudAn 754/61 (53), Uganda S (3), and West Nile (2). Viruses were isolated from Nigeria, the principal area of mammal collecting, and Dahomey, but not from Togo. The possible relationship of these viruses to diseases of man and domestic animals is discussed.

Mokola virus: experimental infection and transmission studies with the shrew, a natural host.

Wild-caught shrews (Crocidura sp.), the only known wildlife host of the rabiesrelated agent Mokola virus, were given various dose levels of Mokola virus by different routes (subcutaneous, intramuscular, and oral), and then were examined for recovery of virus, presence of histopathologic lesions, and ability to transmit virus by bite to laboratory mice. Thirteen shrews, given virus by each of the routes, showed evidence of having become infected. Eleven of these became ill and yielded virus from multiple tissues, in which lesions were observed. Of the two infected shrews that remained asymptomatic, both showed histopathologic lesions and one also yielded virus, while the other was virus-negative (only brain was tested) but transmitted virus to a mouse. Four of the shrews that were virus-positive also transmitted the virus to mice. Thirty other inoculated shrews, as well as control shrews, did not yield virus and failed either to show lesions compatible with Mokola virus infection or to transmit virus.