Leptospirosis: a common-source outbreak due to leptospires of the grippotyphosa serogroup.

In the period August 1-10, 1975, seven cases of leptospirosis occurred in residents of Stewart County, Tennessee. Based on serologic evidence, the infection was caused by leptospires of the Grippotyphosa serogroup. Epidemiologic study showed that the patients apparently acquired their infection while swimming in Cub Creek, a small local stream. Stagnation of the stream resulting from subnormal rainfall may have contributed to the timing of the outbreak. The source of leptospiral contamination for the stream could not be determined.