Emerging and reemerging rickettsial diseases

The article by Kass et al.1 in this issue of the Journal is an appropriate reminder that rickettsialpox, like rickettsial diseases in general, is still with us. The rickettsialpox diagnosed in 13 patients at one hospital in New York City undoubtedly represents only a fraction of the actual cases of this endemic disease. Rickettsia akari is maintained in a zoonotic cycle involving house mice and mites, passing rickettsiae transovarially from one generation of mites to the next. Such firmly established, highly evolved ecologic niches are unlikely to disappear, nor are humans likely to avoid encountering the bacteria that flourish in . . .