Leptospirosis on Oahu: an outbreak among military personnel associated with recreational exposure.

In December 1992, a common-source waterborne outbreak of leptospirosis occurred on the island of Oahu in the state of Hawaii. Two male service persons were hospitalized with culture-confirmed leptospirosis. Eighteen others had similar histories of exposure to the same freshwater swimming site. Although six men developed signs and symptoms comparable to those of the two confirmed cases, none manifested culture or serologic evidence of leptospirosis. The increased incidence of leptospirosis in Hawaii coupled with an increased risk in young males characterize the military population in Hawaii as a high-risk population with respect to leptospirosis.