The first map below shows areas of the United States in red where mass skin testing revealed coccidioidomycosis as an endemic disease in 1957. The following map shows where new outbreaks have led to a new understanding of the disease and an expansion of its known and suspected risk areas. It is important to note that:
A) Two thirds of all Valley Fever cases are contracted in Arizona, with Phoenix and Tucson as the two most affected cities.
B) Kern County (Bakersfield) is the most endemic area in California.
C) There are also endemic areas in Central America, South America, and northwestern Mexico.
D) Environmental conditions have been known to blow spores hundreds of miles out of their original endemic areas to cause infections.
E) Mass testing has not been repeated for more than sixty years.
This classic map was created by Valley Fever Survivor based on source material from the U.S. Geological Survey and the following article: Edwards and Palmer. Edwards PQ, Palmer CE. Prevalence of sensitivity to coccidioidin, with special reference to specific and nonspecific reactions to coccidioidin and to histoplasmin. Dis Chest. 1957 Jan;31(1):35-60.
The next map shows areas identified by the U.S. Geological Survey and CDC endemic to Coccidioides fungus. Notice the red oval at the Dinosaur National Monument site in Utah, far to the north of previously established endemic areas. All ten of the workers at a DNM archeological site on June 19, 2001 became ill with Valley Fever. The exact location of cocci’s growth could not be pinpointed at the time of this particular outbreak, but its suspected growth area in Utah is marked.
Recently confirmed Washington State soil samples were in Walla Walla, Benton, Franklin, and Yakima counties. The discovery of spores in soil near Bend, Oregon provide more evidence of Coccidioides’ northward climb since the original skin testing.
Valley Fever Survivor’s map of suspected and confirmed endemic areas is adapted from multiple sources. Most recently it includes information from the 2018 CDC document “Valley Fever and the Expanding Geographic Range of Coccidioides” and David Filip’s discussion with Dr. Chiller about possible rodent migration that may have caused California’s species of Coccidioides fungus, C. immitis, to have established itself north of its original endemic areas. These areas of suspected growth had not been considered until the discovery in Washington state and are shown in pink.
It is very common for people with a travel history to endemic areas to have their Valley Fever cases diagnosed elsewhere. However, soil testing had only recently confirmed the fungus in Washington State east of the Cascades. Initial consideration of the possibilities behind this discovery are noted in this link. Valley Fever Survivor will keep you updated as new developments arise.
A discussion of the spread to Washington and Oregon is included in the 2014 interview Valley Fever Survivor Co-Founder David Filip had with Dr. Tom Chiller, MD, MPHTM, Deputy Chief of the Centers for Disease Control’s Mycotic Diseases Branch.
Valley Fever spores had also been found in Oregon in 2016. Sharon and David Filip were interviewed soon thereafter about the discovery of soil samples with Valley Fever in Oregon. This article by Markian Hawryluk at The Bulletin is a must read!
If you visit or live in or near an endemic area to this systemic fungal parasite, pay close attention to the environmental conditions mentioned in our Dawn to Dusk page.
Coccidioidomycosis was first discovered in the early 1890’s in Domingo Ezcurra, an Argentinean soldier. Some pathologists believed his skin conditions were the result of cancer. After tissue biopsies his illness was thought to resemble the protozoan coccidia, often found in chickens. To this day the name of coccidioidomycosis still represents this early misdiagnosis. The Ezcurra case was followed for eleven years and he ultimately died of his illness. By 1900 coccidioidomycosis was established as a fungal disease. After an outbreak in the 1930’s in the San Joaquin Valley of California, this disease was given its nickname “San Joaquin Valley Fever,” often shortened further to “Valley Fever.” The disease threatened national security during World War II when thousands of American soldiers became sickened while training in the Southwest. It even affects our military today — as seen during a Navy Seal training exercise in California when 45% of the squad fell ill.
There is still no cure for coccidioidomycosis and no vaccine, but demand for both will be overwhelming once people understand how serious and devastating this disease is. Valley Fever Survivor is working to make sure that happens.