[Dengue 2 in eastern Senegal: serologic survey in simian and human populations. 1974-85]

After the previously reported isolations of dengue 2 virus in eastern Senegal in 1974 and 1981-1982, a retrospective serological study on simian and human populations was carried out in the same area. We investigated 1,095 simian sera collected at regular intervals between 1974 and 1984 from wild caught monkeys and 1,783 human sera from young children less than 11 years old collected during punctual surveys after the rainy season from 1976 to 1985. Sera were tested using HAI test, CF test and for someone's ELISA for specific IgM antibodies. Serological data from monkeys corroborated the virus isolations and demonstrated the existence of two epizootics in 1974-1975 and 1981-1982. No CF antibodies were detected in children sera up to 1981 epizootic when about 11% of tested sera showed a probable infection by dengue 2 virus, no clinical dengue infections were notified by the medical staff. After 1982, serological results showed that the virus maintained in the same area until 1985. The mechanism of the circulation of dengue 2 virus in eastern Senegal is discussed on the basis of these serological results.