An analysis of the subtypes of dengue fever infections in Barbados 2003–2007 by reverse transcriptase polymerase chain reaction

BACKGROUND: To perform a retrospective analysis of patients with IgM antibodies to dengue fever infection to determine the serotypes present by molecular techniques. A representative sample (~20%/per year) of patients diagnosed with dengue fever infection were selected based on the detection of IgM antibodies in the acute phase serum sample. RNA was extracted from each sample and reverse transcribed. Following this, the amplicons were electrophoresed and serotyped based on band sizes. RESULTS: This study consisted of 71 males and 101 females ranging in age from 0 – 50+ yrs giving a total of 172 persons with an average of 34.4 patients per year. Onset averaged 6.9 days ranging from 0–90 days. Common symptoms were as follows: fever (69%), headache (52%), arthralgia (36%), ocular pain (32%), emesis (15%) and lumbar pain (15%). All patients investigated with the exception of one, were infected with DENV-3. CONCLUSION: DENV-3 is currently circulating on the island and not DENV-1 or DENV-2 as in previous years. This has implications for the enhancement of clinical, laboratory and environmental surveillance systems.