Phylogenetic analysis of dengue-3 viruses prevalent in Guatemala during 1996-1998 - Brief Report

Dengue is an acute viral disease transmitted by the Aedes aegypti mosquito which is present in most tropical urban areas of the world. There are four antigenically distinct serotypes, designated dengue-1 (DEN-1), dengue-2 (DE N-2), dengue-3 (DEN-3) and dengue-4 virus (DEN-4). In this study, we determ ined the serotypes of dengue viruses isolated in Guatemala in 1995-1998, an d found that DEN-3 viruses appeared in 1995 and became predominant in the f ollowing three years. We then sequenced cDNAs from fifteen DEN-3 isolates r ecovered during 1996-1998. From the nucleic acid sequences and previously d etermined DEN-3 sequences, a phylogenetic tree was constructed using the ne ighbor joining method. The tree indicated that all fifteen isolates and oth er DEN-3 viruses isolated in Sri Lanka, India, Samoa and Mozambique formed subtype III. More than two decades ago, DEN-3 virus was prevalent in the Ca ribbean, but the isolates obtained at that time belonged to subtype IV Ther efore, we concluded that the 1996-1998 dengue epidemic in Guatemala was cau sed by DEN-3 strains, imported from a tropical area of Asia or Africa or fr om a Pacific island.