Preliminary tests have shown that the tropical rat mite, Liponyssus bacoti, can transmit the agent of rickettsialpox, Rickettsia akari, from mouse to mouse, though present observations do not indicate it to be an efficient vector. In the early tests no attempt was made to prevent test mice from eating the mites, but in one successful transmission to baby mice this could not have occurred. Infection was demonstrated in nymphal progeny, indicating transovarial passage of the agent. The agent was shown to persist in a colony for at least 34 days, and in dead mites for at least short periods.
Though the disease is not now known beyond the limits of New York City, the host habits and much more widely known distribution of I. bacoti compared to that of the presently known natural vector, Allodermanyssus sanguineus, suggest the former is of potential importance in planning control measures or in surveying future foci.
Principal Medical Entomologist, United States Public Health Service.
Laboratory Technician, United States Public Health Service.