Experimental Infection with Rickettsia prowazeki in Rhesus and Vervet Monkeys

Experimental infection with Rickettsia prowazeki was produced in rhesus and vervet monkeys, confirming early observations that these animals are susceptible hosts. Severity of illness was related to size of inoculum and route of inoculation. Subclinical infections were detected in many animals by antibody measurements. Following inoculation with the E strain of R. prowazeki 4 animals showed protection when challenged with the virulent Breinl strain. Typical typhus nodules were observed in the central nervous systems of many animals.