Understanding Rocky Mountain Spotted Fever

Rocky Mountain spotted fever is a bacterial infection caused by Rickettsia rickettssii, which spreads to humans by hard ticks.  It is considered as the most severe and most frequently reported rickett-related illness in the United States. 

It is also known in various names such as "tick typhus," "Tobia fever," "São Paulo fever," "febre maculosa," and "fiebre manchada."  This disease is different from the Colorado tick fever, although both come from the same source.

What is Rocky Mountain spotted fever?

The disease was first recognized in 1896 in Idaho’s Snake River Valley area and was originally called "black measles" because of its characteristic rash. 

By the early 1900s, the recognized geographic distribution of this disease grew to as far north as Washington and Montana, as well as far south as California, Arizona, and New Mexico.  These areas are part of the Rocky Mountain range.

The identity of the infectious organism that causes this disease was discovered by Howard T. Ricketts, an American pathologist.  He reported that this species of bacterium is maintained by nature by a complex cycle involving ticks and mammals, with humans considered as "the accidental host."

The name "Rocky Mountain spotted fever" is some sort of a misnomer, especially when it is becoming apparent, beginning the 1930s, that the disease can occur in areas other than the Rocky Mountain region such as Canada, Mexico, and parts of South America.

Symptoms of Rocky Mountain spotted fever

Initial symptoms of this infectious disease include sudden fever, headache, and muscle pain, followed by a development of rash.  At its early stages, the disease can be difficult to diagnose.  However, without prompt and appropriate treatment, this disease can be proved fatal.

How to treat Rocky Mountain spotted fever?

Appropriate antibiotic treatment (usually with doxycycline or chloramphenicol) is administered immediately when there is a suspicion of Rocky Mountain spotted fever, as delayed treatment would cause the patients to require longer periods of healing and become prone to multiple organ damage.