Application of molecular typing techniques in the 1998 dengue epidemic in Nicaragua

This report presents the results of applying the reverse transcriptase-poly merase chain reaction (RT-PCR) to the analysis of clinical specimens during the 1998 dengue epidemic in Nicaragua. The RT-PCR was validated through co mparison with viral isolation, resulting in a sensitivity of 100% and a spe cificity of 90%. In-country application of the RT-PCR permitted the rapid i dentification of dengue-3 virus as the cause of the epidemic at the beginni ng of 1998 and the detection of the reintroduction of dengue-a virus in the middle of the year. Nineteen isolates of dengue-3 and one of dengue-2 were characterized using the restriction site-specific (RSS)-PCR technique. Thi s showed that the dengue-3 strain belonged to the "Sri Lanka" subtype and t hat the dengue-2 strain belonged to the "Jamaica" subtype, both of which ha ve been associated with hemorrhagic dengue in the Americas. The application of these simple PCR-based strain typing methods in a country endemic for d engue virus infections can help to characterize the transmission dynamics o f this important emerging infectious disease problem and provide this infor mation to local health authorities in a timely manner so that appropriate c ontrol measures can be implemented.