RESUMO
The objective of this study was to elucidate the natural rodent host relationships of Guanarito and Pirital viruses (family Arenaviridae) in the plains of central Venezuela. Ninety-two arenavirus isolates from 607 animals, representing 10 different rodent species, were characterized to the level of serotype. The 92 isolates comprised 19 Guanarito virus strains and 73 Pirital virus strains. The 19 Guanarito virus isolates were from Zygodontomys brevicauda; 72 (98.6%) of the 73 Pirital virus isolates were from Sigmodon alstoni. These results indicate that the natural rodent associations of these 2 sympatric arenaviruses are highly specific and that Z brevicauda and S. alstoni are the principal rodent hosts of Guanarito and Pirital viruses, respectively.
Assuntos
Arenavirus/isolamento & purificação , Roedores/virologia , Animais , Arenavirus/classificação , Arenavirus/genética , Vetores de Doenças , Ensaio de Imunoadsorção Enzimática , Filogenia , VenezuelaRESUMO
Due to the increasing severity of hemorrhagic dengue epidemics during the last years in Venezuela, a retrospective analysis was conducted to identify the behaviour of the dengue virus serotypes circulating in the country and the molecular evolution of dengue virus serotype 2. The data presented here indicates that dengue virus serotypes 1, 2 and 4 are endemic in Venezuela, they circulate simultaneously around the year in the biggest urban cities, however, one particular serotype is predominant during an epidemic period and replaces the virus serotype dominant during the previous epidemic period. The increased severity of dengue fever since 1989 in Venezuela might be associated to the introduction of the Asiatic genotype of virus which replaced the autochthonous Caribbean genotype. The Asiatic genotype is recognised as a more virulent virus.