Dangerous fungal infections are on the rise, and a growing body of research suggests warmer climates may be to blame.

The average temperature of the human body is 98.6 degrees Fahrenheit Infectious disease specialists say it is too hot for most fungi to thrive. But as temperatures rise globally, some fungi may be adapting to cope with more heat stress, including conditions in the human body, a study suggests. Climate change may be creating conditions for some pathogenic fungi. Expand their geographic rangeStudies show.

“Because fungi are exposed to a series of temperatures, there’s a chance that some previously harmless fungi can suddenly become pathogenic,” says Peter Pappas, an infectious-disease specialist at the University of Alabama at Birmingham.

The number of people dying from fungal diseases is increasingPublic health experts say this is partly due to the increasing number of people with weakened immune systems and vulnerable to severe fungal infections. In the year By 2021, at least 7,000 people will die from fungal infections in the U.S., up from hundreds of deaths each year in 1970, according to the Centers for Disease Control and Prevention. There are few effective and non-toxic drugs. To treat such infectionsare there.

Photos: What we know about deadly fungal infections

In a video game and HBO show.the last of us,” A fungus attacks people en masse and turns them into monstrous creatures. The fungus is based on a real genus, Ophiocordyceps, which includes species that infect, disable and kill insects.

No known Ophiocordyceps infections have been found in humans, infectious-disease experts say, but the warming that has fueled the spread of the deadly fungi in the scene is pushing other fungi to better adapt to human hosts and spread into new geographic regions. .

January study in the magazine Proceedings of the National Academy of Sciences showed. Higher temperatures can stimulate some pathogenic fungi to survive faster.

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Duke University researchers have grown 800 generations of Cryptococcus species, a group of fungi that can cause severe disease in humans, at 86 degrees Fahrenheit or 98.6 degrees Fahrenheit. The researchers used DNA sequencing to track changes in the fungal genome, focusing on “genome hopping”—the ability to move from one place to another in the genome.

The activity of such genes can cause mutations and alter gene expression, said Asia Gusa, study co-author and postdoctoral researcher in Duke’s Department of Molecular Genetics and Microbiology. In fungi, Dr. Gusa, gene activity can play a role in helping fungi adapt to stress, including heat.

Dr. Gusa and her colleagues found that the movement speed of the “jump genes” was five times higher in Cryptococcus raised in hot temperatures.

Cryptococcus infections can be fatal, especially in immunocompromised people. Worldwide, at least 110,000 people die from brain infections every year Caused by Cryptococcus fungiThe Centers for Disease Control and Prevention said.

Candida auris, the deadliest fungus reported in about half of US states, appears to have adapted to warmer climates, infectious disease specialists say.

“Fungus is not transmitted from person to person, but through airborne fungal spores,” said Dr. Gusa. “They are in our house, they are everywhere.”

There is an analysis published last year in the journal Clinical Infectious Diseases Some deadly fungi are found in soyl, including Coccidioides and Histoplasma, have greatly expanded their geographic range in the Americas since the 1950s. Andre Speck, co-author of the analysis and associate professor of medicine at Washington University School of Medicine in St. Louis, said warming and other environmental changes related to climate change could have played a role in the spread. .

Coccidioidomycosis, or valley fever, a disease caused by Coccidioides, was once largely confined to the Southwest, Dr. Speck said. People are now being tested in large numbers in most states. Histoplasma infections, common only in the Midwest, were reported in 94% of states, the analysis found. Histoplasma is also transmitted by bat droppings and climate change has been linked to changing bat migration patterns, Dr Speck said.

The World Health Organization has identified Cryptococcus, Coccidioides, Histoplasma, and Candida auris as fungal pathogens of greatest concern to humans.

“We keep saying these fungi are rare, but this must be a very common rare disease because now they’re everywhere,” Dr Speck said.

Write to Dominique Mosbergen at dominique.mosbergen@wsj.com

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