Dengue type 3 virus, Saint Martin, 2003-2004

Abstract

We describe the spread of a dengue virus during an outbreak in Saint Martin island (French West Indies) during winter 2003-2004. Dengue type 3 viruses were isolated from 6 patients exhibiting clinical symptoms. This serotype had not been detected on the island during the preceding 3 years. Genome sequence determinations and analyses showed a common origin with dengue type 3 viruses isolated in Martinique 2 years earlier.

Figure 1

Map of Saint Martin, an island in the Caribbean. The lower map represents the Caribbean subregion. The year of dengue virus type 3 subtype III detection is indicated under the concerned island or country. The upper map is a close-up of Saint Martin. Source: Centre de documentation de l'Institut de Médecine Tropicale du Service de Santé des Armées.

Figure 2

Temporal distribution of the outbreak (adapted from [10]). Bars indicate the suspected dengue patients observed by sentinel physicians; dark squares (curve) indicate laboratory-confirmed cases.

Figure 3

Phylogenetic tree of dengue type 3 subtype III viruses, based on prM/M and partial E nucleotide sequences (nucleotide numbers 437 to 1144) available in GenBank database. Phylograms were constructed with the MEGA 2 program (15), using the Jukes-Cantor algorithm and the neighbor joining method. The percentage of successful bootstrap replicates (1,000 bootstrap replications, confidence probability >90%) is indicated at nodes. The length of branches is proportional to the number of nucleotide changes (percentage of divergence). The strains sequenced in this work are underlined. Dark triangles correspond to viruses of the same group clustering together; dots indicate a change in scale.