Failure of cyclophosphamide to significantly enhance isolation of Rickettsia tsutsugamushi from wild Philippine rats.

Treatment of wild rats from a known scrub typhus focus in the Philippines with cyclophosphamide did not significantly enhance the isolation rate of Rickettsia tsutsugamushi using mouse inoculation techniques. Similarly, cyclophosphamide treatment of mice inoculated with organs of wild rats did not increase the recovery of rickettsiae, and isolation of rickettsiae was about equal from biopsies obtained before and after immunosuppression of wild rats.