Laboratory-acquired Chagas disease.

A laboratory technician developed fever, malaise, headache and non-tender erythematous swelling proximal to the site of accidental inoculation of his thumb, 24 days earlier, with a needle contaminated with Trypanosoma cruzi. Findings included a characteristic rash, remarkable fever, relative bradycardia and leukopaenia--T lymphopaenia with maintenance of a normal helper/suppressor ratio. Trypanosomes were not detected in blood concentrates or in biopsies of an enlarged lymph node and a skin lesion. T. cruzi antibody was first detected 33 days after the laboratory accident, when parasites were first isolated. Therapy with nifurtimox was well tolerated and the patient's serology became negative 9 months after the accident.