Valley Fever Spreading Far Outside American West

American public health officials are becoming more and more concerned about a potentially fatal disease that is spreading across the western United States from the Central Valley of California as far east as Texas. Known colloquially as valley fever and in the medical literature as coccidioidomycosis, this fungal infection has become an epidemic in Arizona and California, but remains virtually unheard of in the rest of the country. The dust-borne fungus, however, can strike visitors to the American West as well as travelers.

What Is Coccidioidomycosis?

The nearly-unpronounceable fungal infection is caused by two species of fungus, Coccidioides immitis and Coccidioides posadaii. These fungi live in dry, alkaline soils at lower elevations in interior California and Texas, and in Arizona, Utah, New Mexico, and most of the states of northern Mexico. They are also found in some locations in Central and South America.

The fungus grows long filaments in the dirt during the local rainy season. When the soil dries out, the fungus catches a ride with dust particles and finds its way into the lungs of passersby. In 60 to 65% of cases, the fungus causes symptoms so mild that they go unnoticed. In the other 35 to 40% of infections, the fungus causes relatively mild, flu-like symptoms. The fever, muscle aches, joint pain, severe cough, and pain when breathing start about about a week after exposure and last about a month.

In about 1 in 150 cases, however, the fungus escapes the lungs and infects other parts of the body. The fungus prefers the lungs, soft tissues, joints, and meninges lining the nerves and brain, in these especially severe cases causing meningitis. The fungus may also cause mild to severe fungal pneumonia, urinary tract problems, and kidney or (in men) prostate infections.  In women, the fungus may cause cervical infections and cell abnormalities that are detectible on the Pap smear. The coccidioidomycosis infection, however, can strike any organ in the body.

Who Gets Coccidioidomycosis?

Every year about 150,000 people come down with symptoms of this fungal infection,  but only about 25,000 are diagnosed as valley fever, California fever, San Joaquin Valley fever, or desert rheumatism. At one time the disease was common only at lower elevations around Phoenix, Arizona and Fresno, California, with booming population the condition is increasing common throughout the American West. About 80% of people who live in the West have antibodies to the disease. And every year about 100 people die from the disease.

Ten Things Desert Dwellers Need To Know About Valley Fever

It only takes one fungus spore to cause an infection with valley fever. And if you travel away from the American west after you inhale that one spore (or, more likely, hundreds or thousands of fungus spores), by the time you come down with symptoms, you may be far outside the part of the country where doctors are sufficiently familiar with the disease to diagnose it quickly.

That's why it's essential for residents and visitors to the American Southwest and northern Mexico to know the basics about valley fever, including these ten important facts.

1. Any activities that kick up dust in the desert increase the risk of acquiring coccidioidomycosis. Riding all-terrain vehicles and participating in archaeological digs are good times for breathing protection. Even a bandana, thrown into the laundry as soon as one comes home, offers some protection.
2. The American Southwest isn't the only place it is possible to catch valley fever. The coccidioidomycosis fungus is also found in Paraguay, Argentina, and northern Mexico. Any place in the Western Hemisphere that has dry, alkaline, salty soils (especially soils that have dried out after irrigation), mild winters, and hot, dry summers is a potential breeding ground for the fungus.
3. People in every state of the United States have been diagnosed with the disease. It is several hundred times more common, however, in California, Arizona, and Texas. When the disease occurs outside the American Southwest, it is always in people who have traveled to the American Southwest, or who have been bitten by an animal (most commonly a house cat) from the American Southwest.
4. People of African or Filipino descent are more susceptible to complications of the disease.  Only about 1 in 150 people of European descent develops a severe case of coccidioidomycosis, but 1 in 5 African-Americans and 1 in 3 Filipino-Americans come down with severe symptoms. Blacks are more likely to develop fungal infections of the bone and Filipinos are more likely to develop meningitis.
5. Hispanics and Native Americans, however, are more likely to die of the disease. The infection also leads to death in people whose immune systems have been compromised by HIV or by treatments for cancer or autoimmune disease.
6. Many people aren't diagnosed with valley fever before the disease spreads to their central nervous systems. When the fungus spreads to the brain, antifungal medications may prevent death, but they do not counteract severe, debilitating fatigue.
7. People who take the kinds of antifungal medications that combat valley fever usually cannot drink alcohol. Taking a single drink can "knock out" a patient who is on the antifungals.
8. People who suffer neurological complications of valley fever are prone to strokes and seizures. Sometimes the first manifestation of the infection is a stroke or seizure.
9. People who have diabetes are especially at risk for coccidioidomycosis. Inside the body, the fungus functions as yeast, feeding on blood sugars.
10. Valley fever strikes 25 times as many people as West Nile virus, but the National Institutes of Health provides 25 times as much research funding for West Nile virus. Encourage your representative in Congress to fund valley fever research.