Important
It is possible that the main title of the report Rocky Mountain Spotted Feveris not the name you expected.

Synonyms

• Tickborne Typhus Fever
• RMSF
• Sao Paulo Typhus

Disorder Subdivisions

• Fulminant Rocky Mountain Spotted Fever

General Discussion

Rocky Mountain spotted fever (RMSF) is an infectious disease that belongs to a group of diseases known as the spotted fever group rickettsioses. It is caused by infection with the bacterium Rickettsia rickettsii (R. rickettsii), which is usually transmitted by a tick bite. When introduced into the body, the bacterium spreads by the bloodstream or lymphatic vessels and multiplies within and damages certain cells lining the inside of small blood (vascular) vessels (i.e., endothelial cells) as well as vascular smooth muscle cells. Such damage leads to inflammatory changes of affected blood vessels (vasculitis), leakage of fluid from the blood vessels, an abnormal accumulation of fluid in body tissues (edema), and additional abnormalities, resulting in the symptoms and findings associated with the disease.

Approximately two to 14 days after initial infection, early symptoms may include a high fever, severe headaches, muscle pain (myalgia), nausea, vomiting, loss of appetite (anorexia), abdominal pain, and/or features. In addition, in most individuals with RMSF, a distinctive rash develops about three to five days after fever onset. The rash often initially appears on the skin of the wrists and ankles and spreads to involve the palms of the hands, the soles of the feet, the forearms, the trunk, the buttocks, and the neck and facial areas. The rash typically initially consists of small, flat pinkish spots (macules) that eventually become raised (papules) and darker. The lesions usually develop "pin-point" reddish spots (petechia) due to localized bleeding (hemorrhaging) and may merge to form larger hemorrhagic patches. In some severe cases, insufficient oxygenated blood supply to certain tissues may lead to areas of tissue loss (necrosis).

R. rickettsii infection may affect blood vessels, tissues, and organs throughout the body, including the lungs, brain and spinal cord (central nervous system), heart, liver, and kidneys. Associated symptoms and findings may vary, depending upon the specific tissues and organs affected. Without timely, appropriate treatment, individuals with severe disease may develop potentially life-threatening complications due to tissue and organ injury and dysfunction.

As its name indicates, the disease was originally recognized in the Rocky Mountain states. It has since been reported throughout the continental United States as well as Mexico, Canada, Central America, and South America. As noted above, in most cases, infection with the R. rickettsii bacterium results from tick bites. Several different types of ticks serve as "vectors" for the disease, transmitting the R. rickettsii bacterium to humans.
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Resources

Lyme Disease Foundation
P.O. Box 332
Tolland
CT
06084
Tel: (860)525-2000
Fax: (860)525-8425
800: (800)886-5963
lymefnd@aol.com
http://www.lyme.org

Centers for Disease Control and Prevention
1600 Clifton Road NE
Atlanta
GA
30333
Tel: (404)639-3534
800: (800)311-3435
http://www.cdc.gov/netinfo.htm
http://www.cdc.gov/

NIH/National Institute of Allergy and Infectious Diseases
6610 Rockledge Drive
MSC 6612
Bethesda
MD
20892-6612
Tel: (301)496-5717
Fax: (301)402-3573
TDD: (800)877-8339
http://www.niaid.nih.gov/

World Health Organization (WHO) Regional Office for the Americas (AMRO)
Pan American Health Organization (PAHO)
525 23rd Street NW
Washington
DC
20037
Tel: (202)974-3000
Fax: (202)974-3663
postmaster@paho.org
http://www.who.ch/