Failure of penicillin prophylaxis in laboratory acquired leptospirosis.

A laboratory technician developed leptospirosis following accidental inoculation, despite prompt administration of parenteral penicillin by an accepted regimen of post-exposure prophylaxis. Another technician was similarly exposed and was given doxycycline; no illness or serological conversion followed. The implications of these cases are discussed and recommendations made for post-exposure chemoprophylaxis with doxycycline.