Diseases Caused by Rickettsia, Orientia, Ehrlichia, Anaplasma, and Coxiella Species
Disease | Organism | Rash or Eschar | Vector | Animal Reservoir | Endemic Region |
|---|---|---|---|---|---|
Typhus | |||||
Rickettsia prowazekii | Trunk to extremities May be absent in Brill-Zinsser disease No eschar | Body lice | No animal reservoir (humans are the primary reservoir) | Worldwide | |
R. typhi, R. felis | Trunk to extremities No eschar | Rat flea, cat flea | Rats, opossums | Worldwide | |
Scrub typhus | |||||
Scrub typhus (tsutsugamushi disease) | Orientia tsutsugamushi | Trunk to extremities Eschar present | Trombiculid mite larvae (chiggers) | Rodents, shrews | Asia-Pacific area bounded by Japan, Korea, China, India, and northern Australia |
Spotted fever | |||||
R. rickettsii | Extremities to trunk No eschar | Ixodid (hard) ticks, including Dermacentor andersoni (wood tick), principally in the western United States, and D. variabilis (dog tick), principally in the eastern, central, and southern United States Amblyomma cajennense (Cayenne tick) and A. aureolatum (yellow dog tick) in Central and South America | Rodents | Western Hemisphere, including most of the United States (except Maine, Hawaii, and Alaska); Central and South America | |
R. sibirica | Trunk, extremities, face Multiple eschars present | Ixodid ticks | Rodents | Armenia, Central Asia, Siberia, Mongolia, China | |
Queensland tick typhus | R. australis | Trunk, extremities, face Eschar present | Ixodid ticks | Rodents | Australia |
African tick typhus (African tick bite fever) | R. africae | Multiple eschars on extremities at the sites of the tick bites | Ixodid ticks | Ruminants (cattle, sheep, goats) | Sub-Saharan Africa, West Indies |
Mediterranean spotted fever (boutonneuse fever)* | R. conorii | Trunk, extremities, face Eschar present | Rhipicephalus sanguineus (brown dog tick) | Rodents, dogs | Africa; India; southern Europe; the Middle East adjacent to the Mediterranean, Black, and Caspian Seas |
R. akari | Trunk, extremities, face Eschar present | Mites | Mice | United States, Russia, Korea, Africa | |
R. parkeri rickettsiosis | R. parkeri | Eschar present | Amblyomma maculatum (Gulf Coast tick) | Rodents | Southern United States, South America |
Pacific Coast tick fever | R. rickettsii subspecies californica (formerly R. philipii) | Eschar present Mild disease | Dermacentor occidentalis (Pacific Coast tick) | Uncertain, likely rodents | California |
Neorickettsial infections | |||||
Sennetsu fever | Neorickettsia sennetsu | Rarely, a petechial rash No eschar | Digenean trematodes (eg, Nanophyetus salmincola) | Fish | Southeast Asia, East Asia, with possible endemicity in other regions of Asia |
Monocytic ehrlichiosis | Ehrlichia chaffeensis | Uncommon, but more common among children No eschar | Ticks (A. americanum, also known as the lone star tick) | White-tailed deer | Southeastern and south central United States |
Granulocytic anaplasmosis | Anaplasma phagocytophilum | None No eschar | Ticks (Ixodes scapularis in the eastern and Midwest United States, I. pacificus in the western United States, possibly I. ricinus in Europe) | Rodents, white-tailed deer | In the United States, the Northeast, mid-Atlantic, upper Midwest, and West Coast; Europe |
Neoehrlichiosis | Neoehrlichia mikurensis | Rashes resemble erythema nodosum or erysipelas No eschar | Ixodid ticks | Uncertain, likely rodents | Europe, Asia |
Q Fever | |||||
Coxiella burnetii | Rare but more common among children No eschar | No vector | Ruminants, cats | Worldwide | |
* Often known by the area in which it occurs (eg, Indian tick typhus, Marseilles fever). | |||||