Material and Method: Prospective observation of the patients who participated in rafting in southern Thailand was conducted between January and December 2010. Demographic, clinical data as well as potential risk factors were collected. Indirect immunofl uorescent antibody test (IFAT) for specifi c leptospirosis IgG detection were examined immediately after rafting and two to three weeks after fi rst samples. Microagglutination Test (MAT) was performed to confi rm diagnosis in cases with seroconversion.

Results: One hundred fi fty eight rafting participants enrolled to the present study of which 150 complied with the protocol and were analyzed. Eleven patients had serological evidence of leptospirosis infection accounting for 7.3% while only three patients were symptomatic. Various serovars are responsible for infection while serovar Icterohemorrhagiae is most common. Persistence of abrasion wound/ laceration wound were likely to be risk factors for infection with p < 0.05.

Conclusion: The laboratory fi ndings in the present study demonstrated that leptospirosis was associated with rafting and a contaminated environment.

Keywords: Leptospirosis, Rafting, Southern Thailand