[Dengue 1 epidemic in the Grand Comoro Island (Federal Islamic Republic of the Comores). March-May 1993].

An epidemic of dengue fever occurred in Grande Comore island from March to May 1993. Dengue 1 virus has been isolated. The epidemic did not affect the other islands of the archipelago. No compound clinical picture, in particular hemorrhagic, was reported. A random sampling survey conducted towards the end of April showed that 26% of the population aged 5 years old or more had IgM dengue antibodies. The epidemic concerned essentially individuals under 45 years of age. The number of inhabitants of Grande Comore affected by the outbreak can be estimated between 56,000 and 75,000. The results of the sero-epidemiological survey allowed to find the serological scar of two previous epidemics of dengue: the first one around 1948, which may correspond with dengue 1, the other one in 1984, probably with dengue 2.