Public health importance of human leptospirosis in the South Pacific: a five-year study in New Caledonia.

A retrospective study of 192 cases of human leptospirosis in New Caledonia (South Pacific) diagnosed between 1989 and 1993 showed that the disease was endemic throughout the territory. The annual incidence rate was 30 per 100,000 population, and the disease was more frequent in males (67.5%). Cases occurred mainly in March each year. Forty isolates were obtained (20.8%) and identified as belonging to serovars icterohaemorrhagiae (28), pomona (6), pyrogenes (3), ballum (2), and javanica (1). Most cases (54.7%) presented as influenza-like illnesses, while classical Weil's syndrome (fever, jaundice, and renal involvement) occurred in only 15.6% of the patients. Severe ocular complications were found in 3.6% of the patients. Local differences in climate, environment and socioeconomic conditions determined the epidemiologic features. These data emphasize the potential public health importance of leptospirosis in the other insular states in the South Pacific.