Every year, there are about 150,000 cases of a disease whose impact in the deserts of the American Southwest "is equal to the impact of polio... before the vaccine," John Galgiani, an infectious-disease physician told Dana Goodyear.

Reported cases have increased tenfold between 1998 and 2011, "and in the most severe cases," Goodyear writes in The New Yorker, there is "no cure."

What is it?

A little-researched and little-known disease called valley fever (or "cocci"), which people can get when they inhale a fungus named Coccidioides immitis, found in dirt and dust. Two-thirds of cases occur in Arizona, where "in 2012, valley fever was the second-most-reported disease."

The fungus infects the lungs, but can also spread to the skin, bones, liver, brain, heart, and the membranes that protect the brain and spinal cord.

Sixty percent of people infected with valley fever show no symptoms, and even in those who do, it can resemble a simple flu and clears itself without treatment. But in some, specifically those patients in which the fungus spreads beyond the lungs, it is far worse. Goodyear writes:

A small subset of patients will suffer long-term health problems; in fewer still, cocci will disseminate from the lungs into other tissue — skin, bones, and, often fatally, the meninges of the brain. For those with cocci meningitis, the treatment can be brutal. Three times a week, in the hospital, patients are administered an anti-fungal called amphotericin B — "amphoterrible" is how doctors refer to it — with a needle to the base of the skull. To prevent headaches, patients sometimes rest for several hours with their feet elevated above their heads.

One patient, a twenty-six-year-old white woman who caught valley fever four years ago, told me that the medicine made her vomit non-stop on a negative incline. She was temporarily paralyzed, underwent three brain surgeries, and has had twenty-two spinal taps. Not long after her diagnosis, the doctors told her mother to make funeral arrangements. Now they tell her she will be on anti-fungals, funnelled through a shunt in her brain, for the rest of her life.

Activities like construction and drilling can kick up the spores of Coccidioides immitis, which are easily spread by the region's hot, dry desert winds.

"With the Southwest drying out and heating up, and development pushing deeper into uninhabited terrain," Goodyear writes, "the range of cocci is likely to increase."

Spores can also travel to faraway places in shipping containers and even donated organs. One Michigan man Goodyear talks to fell sick after buying a used car from Phoenix.

While valley fever is easy to catch and can be extremely serious — even fatal — there is little research funding available for a disease whose impact is so geographically limited. (Beyond Arizona, other affected areas include California, New Mexico, Nevada, Texas, and parts of Central and South America.)

Working with the spores in a lab also poses a major hazard. Goodyear notes that "a group of obstetrics students got [valley fever], though their classroom was two stories above the cocci lab."

A upcoming clinical trial in California has been designed to establish treatment guidelines for those already infected, but most research toward a vaccine still has a long way to go.