Experimental infections of vervet monkeys (Cercopithecus pygerythrus) with three spotted fever group rickettsiae

Vervet monkeys inoculated subcutaneously or intravenously with Rickettsia conorii, R. helvetica or R. massiliae developed rickettsaemia and seroconverted although no clinical, haematological or biochemical evidence of infection was detected. The R. conorii inoculation study indicates that vervet monkeys are not a suitable model for human infections with pathogenic spotted fever group rickettsiae and, therefore, the studies with R. helvetica and R. massiliae cannot be used to predict the pathogenicity of these organisms in humans.