Skip directly to search Skip directly to A to Z list Skip directly to navigation Skip directly to site content Skip directly to page options
CDC Home

Questions and Answers


What are some other U.S.-associated tickborne spotted fevers?

In addition to Rickettsia rickettsia, the agent of Rocky Mountain spotted fever, there are other similar agents transmitted by ticks that have been shown to cause human infections. In the United States, these include Rickettsia parkeri, which is transmitted by Amblyomma maculatum and causes a maculatum infection (a relatively mild, eschar-associated illness). There are also other genetically similar Rickettsia that are thought to cause occasional human illness, including one called 364D (Rickettsia phillipi, proposed).  Because these agents appear to exhibit serologic cross-reactivity with available tests for R. rickettsii, it is likely that some human illnesses currently being attributed to RMSF are actually caused by these distinct rickettsial species, and more research is needed to determine their prevalence and geographic distribution.

What are the symptoms of Rickettsia parkeri and other U.S. tickborne spotted fevers?

The symptoms of ehrlichiosis may resemble symptoms of various other infectious and non-infectious diseases. The initial signs and symptoms generally include:

  • fever
  • headache
  • fatigue
  • muscle aches

Other signs and symptoms may include:

  • occasionally rash
  • distinctive eschar that develops at the site of tick bite
  • thrombocytopenia
  • elevated liver enzymes

What are some examples of imported tickborne spotted fevers?

Internationally, there are numerous examples of Rickettsia species associated with human infection. These include:

Table 1. Tickborne rickettsiae known to cause disease in humans and clinical symptoms of the rickettsial diseases



Geographic Distribution

Clinical Symptoms


Rickettsia aeschlimannii

South Africa, Morocco, Mediterranean littoral

Fever, eschar, maculopapular rash

African tick- bite fever

Rickettsia africae

Sub-Saharan Africa, West Indies

Fever, eschar(s)

Queensland tick typhus

Rickettsia australis

Australia, Tasmania

Fever, eschar, regional adenopathy, rash on extremities

Mediterranean spotted fever or Boutonneuse fever

Rickettsia conorii

Southern Europe, southern and western Asia, Africa, India

Fever, eschar, regional adenopathy, maculopapular rash on extremities

Far eastern spotted fever

Rickettsia heilongjiangensis

Far East of Russia, Northern China, Eastern Asia

Fever, eschar,  maculopapular rash, lymphadenopathy, enlarged lymph nodes

Aneruptive fever

Rickettsia helvetica

Central and northern Europe, Asia

Fever, headache, myalgia 

Flinders Island spotted fever, Thai tick typhus

Rickettsia honei

Australia, Thailand

Mild spotted fever, eschar and adenopathy are rare

Japanese spotted fever

Rickettsia japonica


Fever, eschar(s), regional adenopathy, rash on extremities

Australian spotted fever

Rickettsia marmionii


Fever, eschar, maculopapular or vesicular rash, adenopathy

Mediterranean spotted fever–like disease

Rickettsia massiliae

France, Greece, Spain, Portugal, Switzerland, Sicily, Central Africa and Mali

Fever, maculopapular rash, necrotic eschar

Rocky Mountain spotted fever, febre maculosa, Sao Paulo exanthematic typhus, Minas Gerais exanthematic typhus, Brazillian spotted fever

Rickettsia rickettsii

North, Central  and South America

Fever, headache, abdominal pain, maculopapular rash progressing into papular or petechial rash (generally originating on extremities)

North Asian tick typhus, Siberian tick typhus

Rickettisa sibirica

Russia, China, Mongolia

Fever, eschar(s), regional adenopathy, maculopapular rash

Lymphangitis associated rickettsiosis

Rickettsia siberica mongolotimonae

Southern France, Portugal, China, Sub-saharan Africa

Fever, multiple eschars, regional adenopathy and lymphangitis, maculopapular rash

Tick-borne lymphadenopathy (TIBOLA), Dermacentor-borne necrosis and lymphadenopathy (DEBONEL)

Rickettsia slovaca

Southern and eastern Europe, Asia

Necrosis erythema, cervical lymphadenopathy and enlarged lymph nodes, rare maculopapular rash

‡ Includes 4 different subspecies that can be distinguished serologically and by PCR assay, and respectively are the etiologic agents of Boutonneuse fever and Mediterranean tick fever in Southern Europe and Africa (R. conorii subsp. conorii), Indian tick typhus in South Asia (R. conorii subsp. indica), Israeli tick typhus in Southern Europe and Middle East (R. conorii subsp. israelensis), and Astrakhan spotted fever in the North Caspian region of Russia (R. conorii subsp. caspiae).

In the United States, the most frequently diagnosed rickettsial infection associated with residents returning from international travel is Rickettsia africae (the agent of African spotted fever). This is most often diagnosed among U.S. visitors returning from travel to South Africa, particularly those engaged in safari or ecotourism activities.

How are other tickborne spotted fevers diagnosed and treated?

Many other tickborne spotted fevers exhibit strong immunlogic cross-reactivity with assays for R. rickettsii. It is possible to utilize commercially available serologic assays as a surrogate diagnostic tool, coupled with patient presentation and possible travel history that may point to a specific rickettsial illness. The Centers for Disease Control and Prevention can offer more specialized serologic assays for assessment of the etiologic agent, although these are limited in their ability to clearly define an etiologic agent due to cross-reactivity. If a more specific diagnosis is desired, a skin biopsy of a rash or eschar site can be submitted to CDC for more assessment through PCR or culture.

As with other TBRD, the other spotted fever tickborne diseases described here respond well to treatment with doxycycline, and this is considered the antibiotic of choice. Be sure to tell your physician if you become ill within 2 weeks of a tick bite or exposure to tick habitat, either within the United States or internationally.

How can other tickborne spotted fevers be prevented?

The best prevention is to prevent tick bites. Information on preventing tick bites includes use of personal insect repellents, choosing clothing that limits tick attachment, and avoiding areas where ticks may be present.


To the top

Contact Us:
  • Centers for Disease Control and Prevention
    Division of Viral and Rickettsial Diseases (DVRD)
    1600 Clifton Rd
    Atlanta, GA 30333
  • 800-CDC-INFO
    TTY: (888) 232-6348
    24 Hours/Every Day
  • The U.S. Government's Official Web PortalDepartment of Health and Human Services
Centers for Disease Control and Prevention   1600 Clifton Rd. Atlanta, GA 30333, USA
800-CDC-INFO (800-232-4636) TTY: (888) 232-6348, 24 Hours/Every Day -

A-Z Index

  1. A
  2. B
  3. C
  4. D
  5. E
  6. F
  7. G
  8. H
  9. I
  10. J
  11. K
  12. L
  13. M
  14. N
  15. O
  16. P
  17. Q
  18. R
  19. S
  20. T
  21. U
  22. V
  23. W
  24. X
  25. Y
  26. Z
  27. #