Aspergillus fungi are common spores in compost. Researchers recently found drug-resistant forms of the fungus that can infect humans. Credit: Courtesy of Reeser Manley

Humans can catch drug-resistant lung infections from a common fungus, a recent study out of the United Kingdom has confirmed.

The fungus in question is in the genus aspergillus, a spore-producing mold found everywhere. It grows on dead leaves, compost piles, decaying vegetables and on starchy foods like bread, grains and even on some spices. The study was published last week in the journal Nature Epidemiology.

“It really is everywhere,” said Dr. Seanna Annis, associate professor of mycology at the University of Maine. “We are breathing in [aspergillus] spores right now.”

Normally, inhaling the spores is no problem for humans because a healthy immune system is equipped to handle them. But these infection-causing molds commonly found in gardens, homes and farms are becoming drug resistant and causing possible life-threatening illnesses in humans.

These drug-resistant mold strains are on the rise worldwide and have been driven by heavy uses of agricultural fungicides over the years, the study concluded.

Researchers behind the U.K. study said antifungal resistance can be deadly for people with compromised immune systems. The fungus can also be problematic if the spores are accidentally introduced into the body through improperly sanitized medical equipment, an open wound or open sore. The mold can cause lung or skin infections that are typically treated with the antifungal drug azoles.

Annis describes aspergillus as the “weeds” of the fungi world.

“The spores get in and grow really quick,” she said. “They gather as much of the nutrients as they can, produce more spores and then move on to the next place.”

Because aspergillus fungi are so good at breaking down vegetation, they are an important ingredient in backyard composting. That, and the fact they are so common in soil, means anyone who gardens, composts or does just about anything outside is going to be breathing in a lot of those spores.

There are steps you can take if you feel you are at risk for an infection, or just don’t want to be breathing in mold spores while gardening.

You can leave windows open as much as possible to prevent the buildup of the spores in your house. You can also wear the same N95 masks used to prevent the spread of COVID-19 to avoid inhaling spores while gardening or handling compost.

It can be almost impossible to avoid aspergillus spores given their shear numbers in the environment, the authors of the U.K. study noted. They have found that the drug-resistant forms are now just about everywhere and can spread and reproduce with fungal colonies that have never encountered azoles, creating more drug-resistant strains.


Julia Bayly

Julia Bayly is a reporter at the Bangor Daily News with a regular bi-weekly column. Julia has been a freelance travel writer/photographer since 2000.