Expect More Fungal Infections As Their Geographic Ranges Expand. Histoplasmosis, Climate Change

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- 'Expect more fungal infections as their geographic ranges expand, experts warn,' NBC News, Nov .21, 2022. - Ed. Many fungal infections are found outside areas where the pathogens are thought to be endemic, a new paper says. Climate change may be to blame.

Fungal infections are more widespread than doctors or patients realize, research suggests. And they’re expected to grow all the more so in the coming years.

“We’re definitely seeing disease in locations that we previously have not,” said Dr. George Thompson, an infectious disease specialist at the University of Calif., Davis. “And that’s concerning, because if we’re recognizing those locations, where are the places it’s occurring that just have not been recognized quite yet?” He co-authored an article published Monday in the journal Annals of Internal Medicine, which suggests that more than 10% of fungal infections are diagnosed outside regions where the pathogens are known to be endemic.

Plus, the paper says, misdiagnoses & a lack of data make it difficult to know how prevalent cases really are. That’s becoming a more pressing problem, since research shows that climate change is making these infections more diffuse. For example, coccidioides, the fungus that causes Valley fever, thrives in desert climates, so increased heat & drought have created more hospitable areas for it to grow. The fungus histoplasma, which can cause an illness marked by fever, cough & fatigue, tends to survive longer in high humidity — a condition that’s also becoming more common as temperatures rise. Histoplasma is found in soil that contains large amounts of bird & bat droppings, and climate change is altering the migration patterns of some of those species.

People generally get fungal infections after breathing in spores. Often, the immune system fights these invaders off, or infections result in mild flu-like symptoms that resolve on their own. But some people — usually those with weakened immune systems — can develop life-threatening illnesses such as pneumonia or meningitis. “The great majority of people who get Valley fever will tell you they got a cough that lasts a few weeks & it goes away,” said Dr. Arturo Casadevall, a microbiologist & immunologist at the Johns Hopkins Univ. School of Medicine. “But when people are immunosuppressed or when they just have bad luck because they got a very large dose, these diseases can disseminate, or get outside the lung.”

Typically, different fungal infections are associated with specific regions: Valley fever is most common in the Southwest, for example, whereas histoplasmosis is mostly identified in central & eastern states. But the coccidioides fungus was found in Washington soil in 2014. Thompson’s paper came just weeks after another study revealed high rates of fungal disease diagnoses far outside their traditionally understood geographies. The researchers found that 94% of U.S. states had at least one county with a significant number of histoplasmosis cases, and 69% had at least one county with a significant number of Valley fever cases... https://www.nbcnews.com/news/amp/rcna58258