Valley Fever Might Spread Over The Entire American West This Century

Valley Fever used to be mostly a southern Arizona and southern California Central Valley thing (I remember how surprised I was when I first heard about it after moving to Tucson, since it wasn't in Albuquerque), but climate change is aggravating it (link may be subscription only).  It could spread up to Canada.  And it's really nasty for some people. Filipinos and other people from southeast Asia seem to be extra-vulnerable/totally defenseless:

Officially known as coccidioidomycosis — or “cocci” for short — valley fever is a fungal infection that is transmitted in dust. In the United States, it has mostly plagued humans and animals in Arizona and California’s San Joaquin Valley, where the illness was first described as “San Joaquin Valley fever” more than a century ago.

But a disease that was confined to the arid Southwest for decades appears now to be spreading, with new cases being reported in Washington, Oregon and Utah. At the same time, infection rates are increasing, particularly in California, where rates have risen 800% since 2000.

Now, as health officers attempt to track this emerging infectious disease, researchers say climate change is largely responsible for its spread — much the way malaria, Zika virus and Lyme disease are believed to be getting worse because of global warming.

Cycles of extreme precipitation, along with worsening drought and heat, are creating more of the dangerous dust, researchers say, and worsening wildfires may also be fueling the spread. By the end of the century, valley fever may be a threat across the entire western United States, they say.

“It’s emerging because we have increasing numbers, and it’s emerging because it’s being found in new areas,” said Nancy Crum, a physician with Scripps Health System in San Diego who published a review of valley fever in the journal Infectious Diseases and Therapy last month. “It’s a fungus in the soil, and so if you have really windy, dusty conditions, it can get from one area to the other.”

...The Centers for Disease Control and Prevention estimates that there are about 150,000 valley fever cases in the United States each year, but most researchers say the number is much higher — closer to 350,000. In most of those cases, people who inhale the spores are asymptomatic or do not seek treatment. In some, the cases are missed because neither they nor their doctors know what to look for.

But what is undisputed is that weather patterns play a huge role in the spread of the disease, said Morgan Gorris, an Earth system scientist at Los Alamos National Laboratory in New Mexico and one of the leading researchers of the relationship between valley fever and climate change.

The ideal conditions for valley fever are wet winters followed by dry summers, she said. Coccidioides, the fungus that causes cocci, thrives in rain-soaked soil. When the soil dries and temperatures rise, the fungus breaks up into spores that can be launched into the air in billows of dust. In some cases, the spores can travel up to 75 miles.