Experts predict that mold and yeast will spread more widely in the future. This will increase the risk of infections. Some types of fungi will be able to adapt better and better to climate change and thus also to the temperatures in the human body.

The fungus and pathogen Candida auris is spreading in Germany. It can cause painful ear infections, urinary tract infections or blood poisoning. In 2023, it was detected 77 times nationwide – six times more often than in previous years. This is the result of an evaluation by the National Reference Center for Invasive Fungal Infections.

According to Oliver Cornely, further outbreaks in Germany “must be expected at any time”. The infectious disease specialist at the University Hospital of Cologne warned of this in May 2024 in a lecture on the subject of fungal infections, as “Springer Medizin” reports.

Not only Candida auris, but also other molds and yeasts could spread more widely in the future. The risk of contracting fungal spores is increasing worldwide. This can be attributed to climate change, among other things.

Mold thrives in damp environments. If cellars fill up after a flood, as happened in the Ahr Valley flood disaster, it can take a long time for all the rooms to dry out again. In the meantime, the damp walls provide an ideal breeding ground for mold.

A press release from the Medical University of Graz states: Flooding turns houses into “the perfect habitat for fungi, which can then spread throughout the walls over years or decades and make the residents sick.”

Rising temperatures and extreme drought increase the risk of wildfires. During such a fire, fungal spores can be released from the soil and spread for miles by strong, heat-induced winds.

The Medical University of Graz writes: “This can be seen, for example, in firefighters who are deployed to forest fires, who subsequently develop fungal diseases, or in coastal regions where a higher rate of fungal diseases is noticeable after forest fires, after spores have been spread through the air by the fires.”

Longer periods of drought are a consequence of climate change, and some types of fungi benefit from this. The flesh-eating fungus Coccidioides, for example, only thrives in dry soil. It finds ideal conditions in the San Joaquin Valley in California, for example. The area has suffered from extreme drought in recent years, with no rainfall.

The disease caused by the fungus, coccidioidomycosis, is also known as “valley fever”. The California Department of Health reports an 800 percent increase in infections with Coccidioides between 2000 and 2022. The fungus can lead to fever, cough and weight loss, but also to severe pneumonia with abscesses.

Most fungal species cannot yet withstand the temperatures in the human body and are therefore unable to infect humans. However, climate change could trigger the “stress adaptation machinery” of some species. A fungus that has adapted to the rising air temperatures in order to survive could subsequently also be better able to cope with the body temperature of humans and animals. Some species may benefit from climate change “by gradually adapting to higher temperatures and becoming more common and possibly more virulent,” writes an international team of researchers in a study published in March 2024.

According to the scientists, fungi such as Candida auris show a certain “heat tolerance” and have already adapted to human body temperatures. In addition to Candida auris and coccidioidomycosis, the scientists also mention histoplasmosis, a disease caused by the fungus Histoplasma capsulatum. Its areas of distribution include Germany as well as many South American and South African countries. Those affected suffer from fever, flu-like symptoms, cough and chest pain, joint pain and skin changes.

The World Health Organization (WHO) describes fungal infections as one of the “greatest threats”. In the future, measures to protect risk groups will be particularly important. These include people with a weakened immune system, for example because they are undergoing cancer treatment. For healthy people with a functioning immune system, contact with fungal spores is generally harmless.

In addition, the search for effective treatment options is ongoing. Some fungi are immune to certain drugs that are usually used to treat fungal infections. For example, the yeast Candida auris, which was only discovered in 2009, is resistant to some antimycotics as well as to disinfectants. The solution: a combination of several active ingredients, higher dosages and the search for new active ingredients.

Masks offer protection against infection with fungal spores. But you can become infected with fungi practically anywhere. Mold lurks not only in damp cellars, but also in forests or in organic waste bins.