Dengue haemorrhagic fever in Cuba. I. Serological confirmation of clinical diagnosis.

Serological studies by the haemagglutinin inhibition test to confirm a clinical diagnosis of dengue were done on 406 patients during the dengue 2 epidemic in Cuba in 1981. 49% of the cases were serologically positive; of these 64% was classified as primary and 36% as secondary. The frequency of symptoms is described: the most frequent were fever, headache, malaise and vomiting. Haemorrhagic manifestations predominated significantly in the secondary cases. The white race and female sex were found to predominate in the positive cases.