A retrospective study of the 1996 DEN-1 epidemic in Trinidad: Demographic and clinical features

A retrospective analysis of the 1996 DEN-1 epidemic in Trinidad was undertaken to better understand the clinical and demographic expression of dengue infection in the island during one of the larger epidemics in the past 10 years and following the reintroduction of DEN-1 into the island in 1991 after a gap of 14 years. A total of 393 laboratory-confirmed cases were identified. Of these, notes for 157 patients were available for analysis. The epidemic was island-wide, though most cases occurred in the most densely populated county of St. George. There was a slight predominance of females (51.6%) among the cases, and while all age groups were affected, older children and adults comprised the majority. South Asians among the population predominated. Overall, 27 clinical symptoms were reported. The most common were: fever (98.7%), generalized pain (96.2%) and anorexia (63.1%). Rash, arthralgia, retro-orbital pain and haemorrhage (all mentioned in the WHO clinical description for dengue fever) were reported in <50% of cases. Gastrointestinal symptoms were also very common and occurred in over two-thirds of cases at presentation. Bleeding manifestations were reported in 30% of patients and commonly involved the gastrointestinal tract. Features of DHF were noted in only six (4%) patients and there was one fatality. Deficiencies in documented clinical and laboratory monitoring of patients, coupled with a lack of population-specific laboratory reference ranges, may contribute to underdiagnosis of DHF in Trinidad.