Experimental Rat-Bite Fever

Max TheilerDepartment of Tropical Medicine, Harvard Medical School

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  1. 1. A spirochaete closely resembling the Spirochaeta morsus muris, was demonstrated in the blood of guinea pigs and white mice injected with the blood taken from a typical human case of rat-bite fever.
  2. 2. White mice and rats are readily infected with the spirochaete. These animals show no symptoms but harbor the organism in the blood for a long time.
  3. 3. Guinea pigs inoculated with the spirochaete, after an incubation period of six to fifteen days, develop fever, enlargement of the lymph glands, inflammation, and later induration of the external genitals and loss of hair.
  4. 4. Rabbits were infected by subcutaneous, intradermal, and intratesticular injection of blood containing the spirochaetes. About half of the animals used developed no symptoms, but their blood was infected for guinea pigs for three weeks after inoculation.
  5. 5. In the serum of infected rabbits strong spirochaeticidal properties are developed.