Diseases Caused by Rickettsia, Orientia, Ehrlichia, Anaplasma, and Coxiella Species

Disease

Organism

Rash or Eschar

Vector

Endemic Region

Typhus

Epidemic typhus, Brill-Zinsser disease

Rickettsia prowazekii

Trunk to extremities

May be absent in Brill-Zinsser disease

No eschar

Body lice

Worldwide

Murine (endemic) typhus

R. typhi, R. felis

Trunk to extremities

No eschar

Rat flea, cat flea

Worldwide

Scrub typhus

Scrub typhus (tsutsugamushi disease)

Orientia tsutsugamushi (formerly R. tsutsugamushi)

Trunk to extremities

Eschar present

Trombiculid mite larvae (chiggers)

Asia-Pacific area bounded by Japan, Korea, China, India, and northern Australia

Spotted fever

Rocky Mountain 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 and southern United States

Western Hemisphere, including most of the United States (except Maine, Hawaii, and Alaska); Central and South America

North Asian tick-borne rickettsiosis

R. sibirica

Trunk, extremities, face

Multiple eschars present

Ixodid ticks

Central Asia, Siberia, Mongolia, China

Queensland tick typhus

R. australis

Trunk, extremities, face

Eschar present

Ixodid ticks

Australia

African tick typhus (African tick bite fever)

R. africae

Multiple eschars on extremities at the sites of the tick bites

Ixodid ticks

Sub-Saharan Africa, West Indies

Mediterranean spotted fever (boutonneuse fever)*

R. conorii

Trunk, extremities, face

Eschar present

Rhipicephalus sanguineus (brown dog tick)

Africa; India; southern Europe; the Middle East adjacent to the Mediterranean, Black, and Caspian Seas

Rickettsialpox

R. akari

Trunk, extremities, face

Eschar present

Mites

United States, Russia, Korea, Africa

R. parkeri rickettsiosis

R. parkeri

Eschar present

Gulf Coast tick (Amblyomma maculatum)

Southern United States, South America

Pacific Coast tick fever

R. philipii (364D)

Eschar present

Mild disease

Pacific Coast tick (Dermacentor occidentalis)

California

Ehrlichiosis and anaplasmosis

Monocytic ehrlichiosis

Ehrlichia chaffeensis

Uncommon but more common among children

No eschar

Ticks (A. americanum, also known as the lone star tick)

Southeastern and south central United States

Granulocytic anaplasmosis

Anaplasma phagocytophilum

None

No eschar

Ticks (Ixodes scapularisin the eastern and Midwest United States, I. pacificus in the western United States, possibly I. ricinus in Europe)

In the United States, the Northeast, mid-Atlantic, upper Midwest, and West Coast; Europe

Q Fever

Q fever

Coxiella burnetii

Rare but more common among children

No eschar

No vector needed

Worldwide

* Often known by the area in which it occurs (eg, Indian tick typhus, Marseilles fever).