Seroprevalence of and risk factors for leptospirosis in the City of Manaus, State of Amazonas, Brazil.

INTRODUCTION Leptospirosis is caused by a bacterium of the genus Leptospira. This study aimed at investigating the seroprevalence of and risk factors for leptospirosis in humans in Manaus, State of Amazonas. METHODS Interviews were performed, and 1,000 blood serum samples were examined using a microscopic agglutination test. RESULTS Forty-three cases were positive; there were 10 serotypes, with coagglutination in 8 cases. The most frequently occurring serotypes were Icterohaemorrhagiae (20.7%), Cynopteri (20.7%), Australis (18.8%), and Copenhageni (16.9%), and the Midwest (54.7%) and South (23.8%) had the most cases; these areas lack basic sanitation. CONCLUSIONS Disease occurrence might be reduced through improved basic infrastructural conditions.