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Rocky Mountain Spotted Fever Home > Overview
Overview
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Rocky Mountain Laboratory,
ca.
1928 Hamilton, Montana
(photo provided courtesy of Rocky Mountain Laboratories, NIAID, NIH, Hamilton, Montana) |
Rocky Mountain spotted fever was first recognized in
1896 in the Snake River Valley of Idaho and was originally called
"black measles" because of the characteristic rash. It was a dreaded and frequently
fatal disease that
affected hundreds of people in this area. By the early 1900s, the recognized
geographic distribution of this disease grew to encompass parts of the
United States as far north as Washington and Montana and as far south as
California, Arizona, and New Mexico.
In response to this severe problem, the Rocky Mountain
Laboratory was established in Hamilton, Montana. This
facility is now a part of the National Institute of
Allergy and Infectious Diseases, National Institutes
of Health. Laboratory and epidemiologic studies were
also carried out by the Communicable Disease Center
(now the Centers for Disease Control and Prevention,
or CDC) and are still conducted by scientists in the
Viral and Rickettsial Zoonoses Branch, Division of Viral
and Rickettsial Diseases, National Center for Infectious
Diseases, CDC.
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Dr. Howard Taylor Ricketts
(photo provided courtesy of Rocky Mountain Laboratories,
NIAID, NIH, Hamilton, Montana) |
Howard T. Ricketts was the first to establish the identity
of the infectious organism that causes this disease.
He and others characterized the basic epidemiologic
features of the disease, including the role of tick
vectors. Their studies found that Rocky Mountain spotted
fever is caused by the bacterium, Rickettsia rickettsii.
This species is maintained in nature in a complex life
cycle involving ticks and mammals; humans are considered
to be accidental hosts and are not involved in the natural
transmission cycle of this pathogen. Tragically, Dr.
Ricketts died of typhus (another rickettsial disease)
in Mexico in 1910, shortly after completing his remarkable
studies on Rocky Mountain spotted fever.
The name Rocky Mountain spotted fever is somewhat of a
misnomer. Beginning in the 1930s, it became clear that this disease
occurred in many areas of the United States other than the Rocky Mountain
region. It is now recognized that this disease is broadly distributed
throughout the continental United States, as well as southern
Canada, Central America, Mexico, and parts of South America. Between 1981 and 1996,
this disease was reported from every U.S. state except Hawaii, Vermont, Maine,
and Alaska.
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| Discovery of chloramphenicol and
tetracycline antibiotics in the 1940s led to a sharp decline in RMSF-related
mortality(photo provided courtesy of Rocky Mountain
Laboratories, NIAID, NIH, Hamilton, Montana) |
Rocky Mountain spotted fever remains a serious and
potentially life-threatening infectious disease today. Despite
the availability of effective treatment and advances in medical care,
approximately 3% to 5% of individuals who become ill with Rocky Mountain spotted fever
still die from the
infection. However, effective antibiotic therapy has dramatically reduced the number of deaths caused by Rocky Mountain spotted
fever; before the discovery of tetracycline and chloramphenicol in the
late 1940s, as many as 30% of persons infected with R. rickettsii
died.
Date last reviewed: 05/20/2005 |
