Phylogeny of dengue virus type 3 circulating in Colombia between 2001 and 2007.

Dengue virus type 3 (DENV-3) re-appeared in Colombia in 2001 after 23 years of apparent absence, in the state of Santander in the North-eastern region near to Venezuelan border. In 2002, the virus was isolated in the state of Valle del Cauca in the South-east region near to Ecuadorian/Peruvian border, and in the state of Antioquia in the North-east region near to Panama border. To gain insight into the molecular epidemiology of DENV-3 in Colombia, we sequenced the complete E gene of 21 isolates sampled in the period 2001-2007. Phylogenetic analyses revealed that Colombian strains seem to have been introduced from Venezuela, Ecuador and Peru, but not from Brazil, Argentina, Paraguay or Central America countries. This study also confirms previous report showing that Colombian isolates is closely related to DENV-3 genotype III.

Dengue virus serotype 3 (genotype III) from Colombia: A perspective of its pathogenic potential.

The introduction of DENV-3 genotype III in Latin American countries has been associated with dengueoutbreaks, and the role of the virus with respect to the occurrence of dengue haemorrhagic fever (DHF)has been different depending on the country. We have conducted research on the relative abundance of DENV-3 in relation to the incidence of DHF in a Colombian endemic area. Additionally, it wasexplored using phylogenetic analyses whether or not viruses are genetically distinct in relation to the severity of dengue. Viral isolation was made from serum samples collected during the period fromJanuary 2007 to October 2008. Sequences from the envelope gene of viruses from Colombia andLatin American countries isolated from DF and DHF patients and submitted to GenBank were compared. We found that in 2007–2008 the predominance of DENV-3 declined as compared to 2002–2004(28.3% versus 87.8%), whereas the DENV-1 and DENV-2 predominance increased (54.7% versus2.7% and 16.9% versus 5.4%, respectively). This relative abundance of serotypes coincided with an increase of DHF compared with the period of the highest DENV-3 dominance (25.9% versus 4.6%).Phylogenetic analyses showed that: (i) there is no relationship between DENV-3 clades and the severity of the disease; and (ii) Colombian viruses clustered apart from those coming from countries where DENV-3 has caused severe dengue. The results suggest that DENV-3 could not play any important rolein the occurrence of DHF in Colombia, and that local viruses are genetically distinct from LatinAmerican viruses associated with epidemics of DHF.