Recent Blog Articles
Cardiovascular safety from prostate cancer drugs remains uncertain
Rising alcohol use among older adults
Easily distracted? Try meditation
Harvard Health Ad Watch: Can a wearable device reduce stress?
Listening to your hunger cues
Does your child need to bathe every day?
Can flavonoids help fend off forgetfulness?
Can physical or cognitive activity prevent dementia?
Wondering how much your medical care will cost? New rules could help
Long-lasting healthy changes: Doable and worthwhile
Rocky Mountain Spotted Fever
What Is It?
Rocky Mountain spotted fever is a severe illness caused by tiny bacteria called Rickettsia rickettsii, which are transmitted through the bite of an infected tick. In the eastern United States and in California, the infected tick is usually Dermacentor variabilis, the American dog tick. In most of the western United States, the tick is more likely to be Dermacentor andersoni, the Rocky Mountain wood tick. Humans typically become infected in the spring and early summer.
Once someone is bitten by an infected tick, Rocky Mountain spotted fever bacteria can spread throughout the bloodstream and lymphatic system. The tick must remain attached and be actively feeding to transmit the bacteria. Not everybody who is bitten by an infected tick develops Rocky Mountain spotted fever. It is not clear why some people get the disease and others do not.
To continue reading this article, you must log in.
Subscribe to Harvard Health Online for immediate access to health news and information from Harvard Medical School.
- Research health conditions
- Check your symptoms
- Prepare for a doctor's visit or test
- Find the best treatments and procedures for you
- Explore options for better nutrition and exercise
I'd like to receive access to Harvard Health Online for only $4.99 a month.Sign Me Up
Already a member? Login ».
As a service to our readers, Harvard Health Publishing provides access to our library of archived content. Please note the date of last review or update on all articles. No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician.