Leptospirosis: an underdiagnosed cause of acute febrile illness.

Two cases of leptospirosis diagnosed at the Texas Medical Center in a two-week period are presented. Most cases of leptospirosis go undiagnosed because the symptoms and signs are nonspecific. Leptospirosis should enter the differential diagnosis when symptoms of influenzal illness, aseptic meningitis, and viral gastroenteritis occur, especially if abnormal hepatic and renal function are shown to be present. Many, but by no means all, patients will give history of exposure to livestock or rodents. Diagnosis is best made by serologic methods; Treatment is usually not required since the disease is self-limited, and even in the more severe form, antibiotics have not been conclusively shown to be of benefit.