PENICILLIN IN EXPERIMENTAL SPOTTED FEVER.

Guinea pigs infected with a virulent strain of spotted fever received large doses of penicillin intramuscularly every 4 hours. The injections were begun 48 hours after the onset of fever. Controls included untreated animals and others that received one dose of spotted fever rabbit immune globulin. The penicillin had no effect on the classic symptoms of this disease and all the treated animals died. (The toxicity of penicillin for guinea pigs probably was a contributing factor.) Eight out of 16 controls died; all guinea pigs receiving globulin survived. Penicillin plasma determinations led to the belief that the treatment was adequate to bring about recovery had the agent been of any value.