PA has more soil fungi causing lung infections than previously thought

PENNSYLVANIA — Soil fungi, which cause significant, serious lung infections, have been found in states long thought to be free of environmental threats, including Pennsylvania, according to a recent study by researchers at Washington University School of Medicine in St. Louis.

Climate change is likely why three major species of soil fungi that cause lung infections are spreading beyond traditional ranges to 48 of the 50 states and the District of Columbia, researchers said.

The types are:

  • Histoplasma or Histo, historically found in the Midwest and parts of the East;
  • Coccidioides in the southwest;
  • Blastomyces in the Midwest and South.

Researchers found cases of all three in Pennsylvania, despite outdated maps from federal health officials showing the state free of Coccidioides. The CDC last revised its maps of disease-causing fungi in 1969, the researchers noted.

The soil fungi are disturbed and kicked up into the air by activities like farming, landscaping, and construction, and even by people walking around in fungus-rich environments like caves.

Histo also grows well in soil that contains bird or bat droppings, according to the CDC, which said cleaning chicken coops also puts people at risk of a fungal infection of the lungs.

The Washington University researchers said healthy people who inhale the spores are good at fighting off lung fungal infections, but infants, older adults and people with compromised immune systems can develop fevers, coughs, fatigue and other symptoms mistaken for bacterial or viral infections can, such as COVID-19, bacterial pneumonia and tuberculosis.

The researchers said doctors had for years relied on outdated maps from the 1950s and 1960s that showed the deadly environmental fungi were contained in specific geographic areas. In areas where the fungi were not suspected, doctors may have missed signs of fungal infection of the lungs, leading to delayed or incorrect diagnoses, the researchers suggested.

“Every few weeks I get a call from a doctor in the Boston area — a different doctor each time — about a case they can’t solve,” said Dr. Andrej Spec, the lead author of the study, in a press release.

“They always start by saying, ‘We don’t have a histo here, but it really looks like a histo.’ I’m like, ‘You guys call me about it all the time. They have histo’,” said Spec, an associate professor of medicine at the university and a specialist in fungal infections.

The lead author Dr. Patrick B. Mazi, an infectious disease clinical associate at the university, said people with yeast infections in the lungs often spend weeks trying to get the right diagnosis and appropriate treatment, “and they feel terrible the whole time.”

“You usually have multiple visits to the doctor with multiple choices for tests and diagnoses, but the doctor just won’t consider a yeast infection until they’ve exhausted all other options,” he said.

Results are limited to fungal lung infections in Medicare beneficiaries age 65 and older. Researchers analyzed Medicare fee-for-service claims from all 50 states and the District of Columbia from 2007 to 2016 to find where soil fungi are making people sick today.

Of the 3,143 U.S. counties spread across most of the United States, the researchers found Histo in 1,806, Coccidioides in 339, and Blastomyces in 547 over the nine-year period of the study.

Researchers said that 94 percent of the states had at least one county with a problem with Histoplasma lung infections, 69 percent with Coccidioides, and 78 percent with Blastomyces.

The researchers said their study raises awareness that fungal infections are more common than people realize and are spreading.

“The scientific community has underinvested in research and development of treatments for fungal infections,” Spec said. “I think that’s starting to change, but slowly. It is important that the medical community recognizes that these fungi are essentially everywhere these days and that we need to take them seriously and consider them when making diagnoses.”