Leptospirosis risk in public cleansing and sewer workers.

The degree of leptospirosis risk was investigated in 80 sewer and 120 public cleansing workers. They were interviewed and their serum samples tested for the presence of leptospiral antibodies by the sensitised erythrocyte lysis (SEL) test. Another 100 control subjects matched by sex, age and ethnic group were similarly studied. The study subjects had higher seroprevalence than the controls--over six times higher for SEL titres of greater than 1:100 and over 1.5 times for titres of greater than 1:25. The highest seroprevalence was found in workers cleaning wet markets and food centres. There was no significant correlation between the prevalence of positive titres and symptom prevalence or hospitalisation. Five of the study subjects (all sewer workers) gave a history of jaundice.