A serological survey of leptospirosis in Gippsland dairy farmers.

Serological testing for leptospirosis was performed on sera from 1074 persons who were attending the 1983 Gippsland Field Days. The most common serological reactions were against representative serovars from serogroups Hebdomadis (12%), Panama (2%), Tarassovi (2%) and Pomona (1%). The reactions against serogroup Hebdomadis were attributed to exposure to serovar hardjo; the milking of dairy cows was found to be a major risk factor. The high prevalence of seropositive results among clinically normal dairy farmers highlights the need for caution in interpreting the results of laboratory testing for leptospirosis.