Leptospirosis in trout farmers.

A worker on a trout farm died from serologically confirmed leptospirosis. Four other workers at the trout farm had recently had an influenza-like illness; one had had jaundice. The man with jaundice had high leptospiral antibody titres, and two others had titres of 1/30. The remaining serum sample was negative. Family members and neighbours not associated with the farm had no detectable leptospiral antibodies. There was evidence of rat infestation around the ponds and in a shed used for storing trout food. Pond water or trout food contaminated with rat urine is believed to have been responsible for the outbreak. Another case occurred in a fish farmer elsewhere and it is thought he was infected through wading in rat polluted water with defective rubber boots. A survey to determine the incidence of leptospirosis in fish farm workers is under way.