Arbovirus studies in Luanda, Angola. 2. Virological and serological studies during an outbreak of dengue-like disease caused by the Chikungunya virus.

An outbreak of dengue-like disease was observed in Luanda, Angola, at the end of 1970 and beginning of 1971. Chikungunya virus was isolated from the blood of a patient with typical symptoms of dengue and from a pool of Aedes aegypti mosquitos. A survey for antibodies to arboviruses in the sera of persons living in Luanda showed that the Chikungunya virus was indeed responsible for the outbreak. The fact that this outbreak immediately preceded and continued concurrently with a yellow fever epidemic in Luanda shows that two arboviruses from different antigenic groups may circulate simultaneously in the same ecological area.