Rickettsial infections
| Rickettsial infections |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Pathophysiology & Etiology
Classification by Antigenic Group
- Typhus fevers
- Spotted fevers
- Orientia
- Coxiella-Q Fever
- Bartonella-Bartonellosis
- Ehrlichia
- Anaplasma
- Neorickettsia
References
http://wwwn.cdc.gov/travel/yellowBookCh4-Rickettsial.aspx
History and Symptoms
Clinical presentations of rickettsial illnesses vary, but common early symptoms, including fever, headache, and malaise, are generally nonspecific. Illnesses resulting from infection with rickettsial agents may go unrecognized or are attributed to other causes. Atypical presentations are common and may be expected with poorly characterized nonindigenous agents, so appropriate samples for examination by specialized reference laboratories should be obtained. A diagnosis of rickettsial diseases is based on two or more of the following: 1) clinical symptoms and an epidemiologic history compatible with a rickettsial disease, 2) the development of specific convalescent-phase antibodies reactive with a given pathogen or antigenic group, 3) a positive polymerase chain reaction test result, 4) specific immunohistologic detection of rickettsial agent, or 5) isolation of a rickettsial agent. Ascertaining the likely place and the nature of potential exposures is particularly helpful for accurate diagnostic testing.
References
http://wwwn.cdc.gov/travel/yellowBookCh4-Rickettsial.aspx
Treatment
Treatments for most rickettsial illnesses are similar and include administration of appropriate antibiotics (e.g., tetracyclines, chloramphenicol, azithromycin, fluoroquinolones, and rifampin) and supportive care. Treatment should usually be given empirically prior to disease confirmation, and the particular antimicrobial agent and the length of treatment are dependent upon the disease and the host. No licensed vaccines for prevention of rickettsial infections are commercially available in the United States
Acute Pharmacotherapies
References
http://wwwn.cdc.gov/travel/yellowBookCh4-Rickettsial.aspx
Primary Prevention
With the exception of the louse-borne diseases described above, for which contact with infectious arthropod feces is the primary mode of transmission (through autoinoculation into a wound, conjunctiva, or inhalation), travelers and health-care providers are generally not at risk for becoming infected via exposure to an ill person. Limiting exposures to vectors or animal reservoirs remains the best means for reducing the risk for disease. Travelers should be advised that prevention is based on avoidance of vector-infested habitats, use of repellents and protective clothing, prompt detection and removal of arthropods from clothing and skin, and attention to hygiene.
Q fever and Bartonella group diseases may pose a special risk for persons with abnormal or prosthetic heart valves, and Rickettsia, Ehrlichia, and Bartonella for persons who are immunocompromised.
References
http://wwwn.cdc.gov/travel/yellowBookCh4-Rickettsial.aspx
Acknowledgements
The content on this page was first contributed by: C. Michael Gibson, M.S., M.D.