Death dust: the Valley Fever menace

Dana Goodyear's latest piece for the New Yorker from Los Angeles is about Valley Fever. Death dust, they call it in the headline. The Centers for Disease Control is reporting a tenfold increase in infections from the toxic fungus Coccidioides immitis, which lives in the soil until it gets liberated. She focuses on Kern County in the the San Joaquin Valley and in Lancaster, which is in Los Angeles County.

In soil, C. immitis exists in chains of barrel-shaped units called arthroconidia; airborne, these fragment easily into lightweight spores. C. immitis is adapted to lodge deep: its spores are small enough to reach the end of the bronchioles at the bottom of the lungs. We can breathe them in, but we can’t breathe them out. Once in the lung, the spore circles up into a spherule, defined by a chitinous cell wall and filled with a hundred or so baby endospores. When the spherule is sufficiently full, it ruptures, releasing the endospores and stimulating an acute inflammatory response that disrupts blood flow to the tissue and can lead to necrosis. The endospores, each of which will become a new spherule, travel through the blood and lymph systems, allowing the cocci to spread, as one specialist told me, “anywhere it wants.” In people with weakened immune systems, cocci can take over.

Every year, there are some hundred and fifty thousand cases. Only forty per cent of people infected are symptomatic, and the signs—fever, cough, exhaustion—can be hard to distinguish from the flu. 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.

Cocci is endemic to the desert Southwest—California, Arizona, New Mexico, Nevada, Texas—and to the semi-arid parts of Central and South America. Digging—building, drilling, tilling, clearing—stirs it up, and dry, hot, windy conditions, a regional feature intensified by climate change, disperse it. In recent years, infections have risen dramatically.

Enjoy.