The use of direct sequencing of dengue virus cDNA from individual field-collected Aedes aegypti for surveillance and epidemiological studies

The relative efficiencies of four methods to extract viral RNA from individ ual dengue-2 virus (D-2V)-infected mosquitoes, Aedes aegypti (L.) (Diptera: Culicidae), were compared. The most efficient of these methods was then us ed to extract viral RNA for the preparation of cDNA from the abdomens of si x engorged D-2V-infected mosquitoes and sera from three dengue fever (DF) p atients collected in an isolated rural town in Colombia. Comparisons of vir al envelope (E) gene sequences from each of these strongly suggested that t he D-2V population which circulated in this study area was a homogeneous ge notype which was unrelated to any of the D-2 viruses isolated from elsewher e in the world. When coupled with our rapid method to identify viruses in i ndividual mosquitoes (Romero-Vivas et al. (1998) Medical and Veterinary Ent omology, 12, 101-105), the methodology we describe should be useful for epi demiological and surveillance studies of dengue viruses and other arbovirus es.