Human leptospirosis in the Seychelles (Indian Ocean): A population-based study

A leptospirosis surveillance program was carried out for 12 months on the e ntire population of the Seychelles. Diagnosis was assessed by both microagg lutination test and polymerase chain reaction (PCR) assay. In this populati on of 74,331, leptospirosis was clinically suspected in 125 subjects and co nfirmed in 75 patients (incidence of 101 per 100,000; 95% confidence interv al = 79-126). Leptospirosis was more frequent in middle-aged males with env ironmental exposure. Eight serogroups were identified and Icterohaemorrhagi ae (31%) and Hurstbridge (20%) were the most frequent. Hurstbridge, a recen tly identified new serogroup, was implicated in severe cases and death. Inf luenza-like forms accounted for 37% of the cases while jaundice, acute rena l failure, and pulmonary hemorrhage occurred in 52%, 28%, and 19%, respecti vely. Death occurred in six patients and was related to pulmonary hemorrhag e. The PCR result was positive after completion of treatment in eight patie nts, suggesting that the administered five-day course of penicillin may be inadequate to eradicate the bacteria.