Epidemiology of human leptospirosis in Trinidad and Tobago, 1996-2007: a retrospective study.

A retrospective study to describe the epidemiology of human leptospirosis in Trinidad and Tobago during 1996-2007 was conducted. All confirmed cases of leptospirosis was analyzed according to age, sex, seasonality and geographic distribution. A total of 278 cases were recorded, with an average annual incidence rate of 1.84 per 100,000 population. Seventy-five percent of the cases occurred during the wet season, with the highest number of cases recorded in November. A positive correlation was found between number of cases and rainfall. Males constituted 80% of all cases, and the overall male:female ratio was 4.6:1. The total case fatality rate was 5.8%, with deaths among males four times more common than in females. Clinical leptospirosis was greatest in the 10-19 age group and lowest in the 0-9 age group. The total prevalence was 22 per 100,000 population, with the highest prevalence 41 per 100,000 recorded in the regional corporation of Sangre Grande and the lowest (6 per 100,000) in the city of Port of Spain. The lack of important information and active surveillance showed that the level of awareness of the disease is low in the country. The disease is still under-reported, and is considered to be of significant public health importance.