Inmates of the Pleasant Valley State Prison in California, US are haunted by the deadly valley fever.
In the past three years, more than 900 inmates at the prison have contracted the fungal infection.
At least a dozen inmates in Central California have died from the disease, which is on the rise in other western states of the US, including Arizona, where the health department declared an epidemic after more than 5,500 cases were reported in 2006, including 33 deaths.
The disease, coccidioidomycosis, is caused by a fungus inhaled by its victims. Researchers say the fungus survives in the surface of soil in a relatively narrow geographic band of the country and in Central and South America, in regions characterized by very hot and dry summers and winters that are mild and have little rainfall.
In most cases, the infection starts in the lungs and is usually handled by the body without permanent damage. But serious complications can arise, including meningitis; and, at Pleasant Valley, the scope of the outbreak has left some inmates permanently disabled, confined to wheelchairs and interned in expensive long-term hospital stays.
About 80 prison employees have also contracted the fever, Pleasant Valley officials say, including a corrections officer who died of the disease in 2005.
What makes the disease all the more troubling is that its cause is literally underfoot: the spores that cause the infection reside in the region's soil. When that soil is disturbed, something that happens regularly where houses are being built, crops are being sown and a steady wind churns, those spores are inhaled. The spores can also be kicked up by Mother Nature including earthquakes and dust storms.
"It doesn't matter whether you're custody staff, it doesn't matter if you're a plumber or an electrician," said James A. Yates, the warden at Pleasant Valley. "You breathe the same air as you walk around out there."
The disease has infected archaeologists digging at the Dinosaur National Monument in Utah and dogs that have inhaled the spores while sniffing for illegal drugs along the Mexican border.
The epidemic at the prison has led to a clash of priorities for a correctional system that is dealing with below average medical care and chronic overcrowding.
Last fall, heeding advice from local health officials and a federal receiver charged with improving the state's prison medical care, the Department of Corrections and Rehabilitation delayed plans to add 600 new beds out of concern that the construction might stir up more spores.
Officials at the prison blame the construction of a state hospital nearby for causing a spike in valley fever. The construction was under way from 2001 to 2005, and valley fever hit its peak here in 2006, when the disease was diagnosed in 514 inmates.
This year, about 300 cases have been diagnosed among inmates at the prison.
California reported more than 3,000 cases of valley fever in 2006, the most in a decade. Explanations for the spike have included increased residential development and changes in weather patterns that have resulted in increased blooms of the fungus.
Other prisons in the Central Valley of California have had increases in the number of fever cases in recent years, but in none has the rate of infection been higher than at Pleasant Valley, where about one inmate in 10 tested positive in 2006.
Even allowing for the nearby construction, experts say they do not know why the disease is so rampant here.
"Is the soil surrounding Pleasant Valley different?" asked Dr. Demosthenes Pappagianis of the University of California, Davis.
"There's a lot we still need to know about it," said Dr. Pappagianis, a professor of medical microbiology and immunology who has been studying valley fever for more than 50 years.
For the 11,000 non-inmate residents of Coalinga, about 200 miles southeast of San Francisco, the disease has been a fact of life for generations. "We just deal," said Trish Hill, the city's mayor. "You don't do stupid things like go out on windy days or dig in the dirt."
Inmates appear to be especially susceptible to the disease, in part because they come from areas all over the state and have not developed an immunity to the disease. California corrections officials are preparing new guidelines for prison design, including ventilation and landscaping.
"Prisons tend to have a lot of bare dirt, and that has some security benefit," said Deborah Hysen, the corrections department's deputy secretary of facility planning. "But in the case of valley fever, you want to really contain the soil."
At Pleasant Valley, officials say the outbreak of valley fever places a burden on the institution, requiring guards to escort inmates to local hospitals, where stays can last months and result in medical and security costs of $1 million and more, said Dr. Igbinosa, the medical director.