O'nyong-nyong Fever: An Epidemic Virus Disease in East Africa

Summary

1. 1)

   Between July and December 1959 four districts in Uganda and Kenya were visited while o'nyong-nyong fever was epidemic. This paper records the results of vector studies made during these visits.

2. 2)

   Each area visited is briefly described, and an account is given of the biting arthropods encountered in different situations there.

3. 3)

   The only situation in which the human inhabitants of all districts were bitten severely by arthropods was in huts at night, where only three species of insect were recorded in numbers. These comprised the bed-bug, Cimex hemipterus, and the mosquitoes Anopheles funestus and A. gambiae.

4. 4)

   Certain known features of the epidemic are considered in relation to the distribution and habits of these insects, and it is concluded that the main vector was A. funestus.

5. 5)

   This conclusion is briefly discussed, and it is noted that this constitutes the first record of an anopheline mosquito being recognized as the principal vector in an epidemic of virus disease in man.