In the Southwestern United States, rattlesnakes and mountain lions aren't the only desert inhabitants to watch out for. Also potentially deadly is a fungus that grows in the soil in this part of the country. Its medical name is Coccidioides.

Disturbances to the soil caused by wind, construction, and natural disasters release the fungal spores into the air. People and animals that inhale them may contract an infectious disease called valley fever.

Valley fever most commonly infects the lungs. About 60% of people who get infected with valley fever either experience no symptoms at all, or experience very mild flu-like symptoms. Another 30% experience mild to moderate symptoms such as fatigue, cough, chest pain, fever, headache, and joint aches. Some of these people develop a painful rash of red bumps, typically on the shins. These otherwise healthy people will more than likely recover without treatment.

It's people with already weakened immune systems who are most susceptible to more serious side effects. Some may develop nodules or cavities in the lungs that may require surgery. In others, the disease spreads from the lungs to other tissues such as the skin, bones, or joints. This can lead to meningitis, a serious condition that can cause death.

What can be done?

As of now, there isn't a cure for valley fever, but there are anti-fungals that can help control the fungus. The infection is rarely fatal, resulting in death in less than 1% of cases.

Valley fever isn't a new disease, but it's a growing problem in the Southwest mainly because of the increasing numbers of people moving to the area. There are currently about 150,000 new infections each year.