Drug-resistant ringworm fungus spreads to 29 countries

A drug-resistant strain of ringworm fungus has been identified in 29 countries, according to a new study by the CDC. The fungus, which causes itchy, scaly, circular skin rashes and can lead to athlete’s foot, is resistant to terbinafine, the standard antifungal medication used in cream or pill form. This resistance allows infections to persist for months and complicates medical treatment.

Researchers analyzed data from March 2022 through the end of 2025, finding that reported cases of the drug-resistant fungus tripled during that timeframe. While the first U.S. case was reported in 2023, most documented cases have been found in Europe, which researchers suggest may be due to more robust surveillance and laboratory testing rather than higher infection rates.

Health officials believe cases are likely being undercounted in parts of Africa, India, and the Middle East, where the fungus is already common. Limited access to advanced testing and tracking tools in these regions may be preventing an accurate measurement of the global spread.