PARTIAL NUCLEOTIDE AND AMINO-ACID-SEQUENCES OF THE ENVELOPE AND THE ENVELOPE NONSTRUCTURAL PROTEIN-1 GENE JUNCTION OF 4 DENGUE-2 VIRUS-STRAINS ISOLATED DURING THE 1981 CUBAN EPIDEMIC

In 1981, an epidemic of dengue hemorrhagic fever (DHF) caused by dengu e-2 virus occurred in Cuba. This was the first DHF epidemic reported i n the Western Hemisphere. In this study, we have analyzed four dengue- 2 Cuban strains for two short genomic fragments: one on the envelope ( E) glycoprotein and one at the E/nonstructural protein-1 (NS1) gene ju nction. The E segment of these 1981 Cuban isolates were more closely r elated to older dengue-2 virus strains such as New Guinea C 1944, Thai land 1964, Sri Lanka 1968, and Burma 1976 than to more recent isolates of this virus from Jamaica and Vietnam. More than 9% of the divergenc e with strains isolated from Jamaica and Vietnam was observed at the E /NS1 gene junction. One nucleotide change was observed between the fir st strain isolated during the epidemic and the rest of the Cuban strai ns. This mutation induced a nonconserved amino acid change from phenyl alanine to leucine at position 43 that was not observed in any of the other strains with which it was compared.