[Retrospective sero-epidemiologic survey on dengue virus in the municipalities of Cienfuegos and Palmira].

A retrospective seroepidemiologic survey is made in the municipalities of Cienfuegos and Palmira to determine the presence of neutralizing antibodies to Den-1 and -2 virus in the population. It was found that 21.4% of the population studied had antibodies to Den-1, 12.3% to Den-2, and that 5.5% had been infected by the two serotypes (secondary infection). It became apparent that in the Palmira municipality the percentage of infection due to Den-1 was higher and it was found that in 1980-1981 there was a late dengue (Den-1) outbreak. Therefore, this municipality was probably the only in the country with 2 epidemic outbreaks due to two dengue serotypes (1 and 2) in a 6 month interval. The potential relationship between this fact and the high lethality of hemorrhagic dengue fever in this municipality is established. The influence of environmental, social, and sanitary factors on the risk of infection is suggested. It was found that Whites and Blacks are equally infected and that infection is not a random phenomenon, instead it is favored by the presence of vectors in and around the housing.