The BBC have reported on a very particular fungal disease that is based in a particular area of the US.
Rather like other chronic fungal infections coccoidioidomycosis can often go unnoticed for some time, but once it is diagnosed and treated with antifungal drugs it improves but doesn't go away - Valley fever is another incurable respiratory fungal infection.
Typically found in people who live or have visited some extremely dry areas of the Americas (Arizona, California, Utah, New Mexico and Texas, plus Mexico and Argentina), Valley fever is inhaled in the dust.
- Two out of three infected people experience no symptoms
- Others get flu-like symptoms lasting a month
- One in 20 gets pneumonia and in one in 100 cases it infects the brain - with potentially fatal results
Professor John Galgiani has studied the illness for 30 years and founded the Valley Fever Center for Excellence at the University of Arizona in Tucson. He estimates there is a 3% chance of infection if you spend a year in a highly endemic area, and only a 1% chance of getting sick.
But people can become infected in the most improbable ways however long the odds, he says. The wife of a scientist in the San Francisco Bay area contracted it after she shook out the jeans he had been wearing on a trip to the San Joaquin Valley.Continue reading the main storyDr Galgiani thinks the increase in cases is partly due to better reporting and partly population growth, but says differing weather conditions lead to yearly variations - 2012 is looking like it will have fewer infections than 2011. If dry follows wet, that means a lot of airborne fungal spores.
He doubts that increased construction in the desert plays a part. "It's actually hard to show that human activity has any effect. Many endemic areas are quite sparse and looking at who comes into the clinic, it's not overly represented by construction [workers]."
There's nothing you can do to mitigate risk, he says. Masks, for example, can't prevent a single spore being breathed in, but increased awareness will mean earlier diagnoses and better health outcomes.