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We’re willing to bet you didn’t have “widespread fungal infections” on your 2022 headline bingo card… but here we are.

Research suggests that fungal infections are significantly more widespread than doctors and patients alike have realized. And they’re expected to grow more in the coming years! 

Dr. George Thompson, an infectious disease specialist at the University of California, Davis, co-authored an article published 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 (where they’re normally found).

It’s enough to concern Dr. Thompson. “We’re definitely seeing disease in locations that we previously have not. 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?”

The paper also says misdiagnoses and a lack of data make it difficult to know how prevalent cases really are. Global changes in climate are making these infections more pervasive. 

Take Coccidioides, for example. The fungus causes Valley Fever, which thrives in desert climates. Increased heat and drought in near bye areas have created more hospitable areas for it to grow.

Then there’s Histoplasma. It can cause an illness, Histoplasmosis, marked by fever, cough, and fatigue. It survives longer in high humidity, becoming more common as temperatures rise. 

Histoplasma is found in soil containing large amounts of bird and bat droppings, and climate variability alters some species’ migration patterns.

People commonly get fungal infections after breathing in spores. For most, the immune system fights these invaders off, and most infections result in mild flu-like symptoms that clear up on their own. 

But people 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, and it goes away,” said Dr. Arturo Casadevall, a microbiologist and immunologist at the Johns Hopkins University 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.”

Different fungal infections are connected with specific regions. For example, Valley Fever (from Coccidioides spores) is most commonly found in the Southwestern US, whereas Histoplasmosis is mostly established in central and eastern states. But that’s changing. Coccidioides fungus was found in Washington soil in 2014.

Another study has revealed elevated rates of fungal disease diagnoses well outside their traditional locations. 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.

“Over the last few years, I’ve started to get a lot of requests to help with these diseases,” said Andrej Spec, a co-author of that study and infectious disease specialist at the Washington University School of Medicine in St. Louis. “Frequently, I would get a request that starts off with, ‘Interestingly enough, we don’t have this disease in Massachusetts. But here’s a patient who’s never traveled from Massachusetts, and he has it, so funny thing.’ But I’m like, ‘You do have it; it’s just the maps are not up to date anymore.'”

According to Spec, the last study that updated geographic distributions of disease-causing fungi in the U.S. based on patient data was in 1969.

In 2019, an analysis determined that fungal infections were increasing and suggested that fungi may be commonly overlooked as sources of infection. In October, a World Health Organization report also found that severe fungal infections became more prevalent among people with pre-existing health issues during the Covid pandemic.

Dr. Casadevall said many U.S. hospitals don’t report fungal infections to the CDC and that the agency has a history of not prioritizing the collection of this data because fungi generally don’t cause outbreaks. The CDC received more than 20,000 Valley Fever reports and 1,100 reports of confirmed or probable Histoplasmosis in 2019. 

Thompson and other infectious disease experts are calling for national surveillance of fungal infections and urging doctors to test for them more often. 

Fungal infections aren’t easily detected in routine testing. If doctors are unaware of a risk because of outdated data, they may not order the proper tests, which may delay a diagnosis—taking longer to get the patient treated. That results in higher medical costs and a greater chance of serious illness or death. In some cases, fungal infections can take months of treatment to clear and may become chronic. 

Dr. David Denning, chief executive of Global Action for Fungal Infections, an advocacy and research group, said some rapid tests allow doctors to diagnose fungal infections within hours or minutes. Still, they’re not widely available in the U.S. The standard test method is to send a urine or blood sample to a lab, then wait several days for the result.

“There are very few molecular tests for fungi approved by the FDA,” Denning said. “The FDA rules are pretty stringent, which is a good thing, but it’s also a bad thing because the whole of Europe is using these tests, and in the U.S., there’s too much of a barrier to get these tests adopted on a routine basis.”

Thompson said many people aren’t diagnosed at all: “There’s probably a significant number of patients who were never diagnosed directly and really suffered a lot more morbidity from their disease.”

What can you do about it? Be aware and advocate for yourself! If you’re dealing with a health issue and your doctors just can’t seem to figure it out, encourage them to look beyond what is normal in your area. Just because a certain illness (or fungus) isn’t typically seen outside of a specific area doesn’t mean it CAN’T be. Things are changing, and nobody can stay on top of everything. It’s up to each and every one of us to speak up when it comes to our health and the health of those we love!


WSU Study