[Epidemic outbreak of dengue virus 2/Jamaica genotype in Bolivia]

Abstract

Objective: To confirm an epidemic outbreak of Dengue virus in the city of Santa Cruz, Bolivia, and to determine the serotype of the virus, to estimate the rate of attack and the proportion of symptomatic infections.

Material and methods: In March 1997, a seroepidemiological survey was conducted with random sampling in a central district of the city of Santa Cruz, Bolivia. Information on recent acute illness and febrile episodes was gathered, and venous blood samples were obtained. Levels of antidengue IgM were determined by MAC Elisa and the virus was typified with RT-PCR.

Results: IgM antibodies were detected in 6.5% of adults (CI 95% 3.4-9.6) and 5.1% of children (CI 95% 2.0-8.2). Circulating virus was identified as Dengue serotype 2, subgroup Jamaica. Less than half of the infected children experienced a symptomatic infection compared to almost 90% of adults.

Conclusions: The estimated attack rates are compatible with a Dengue epidemic outbreak in Santa Cruz. The introduction of the serotype 2/ subgroup Jamaica virus into the country increases the risk of hemorrhagic Dengue.