Patterns of rickettsemia and antibody response in silvered leaf monkeys (Presbytis cristatus) after inoculation with virulent and avirulent strains of Rickettsia tsutsugamushi.

Most silvered leaf monkeys inoculated with selected strains of Rickettsia tsutsugamushi developed rickettsemia. The time of onset and the duration of rickettsemia were related to the infecting strains, but these parameters could not be correlated with the virulence of the strain. The rickettsemia was not terminated by the appearance of humoral antibody, as detected by the indirect fluorescent antibody test. The specificities of the antibody responses were related to the antigens present in the infecting strains.