evidence: Studies from the 1950s and 60s indicated that fungal lung infections were a problem only in certain parts of the country. The new study, available online in Clinical Infectious Diseases, shows that is no longer the case. Doctors who rely on outdated maps of disease-causing fungi may miss the signs of a fungal lung infection, resulting in delayed or incorrect diagnoses, the researchers said. [...] People develop fungal lung infections after breathing in spores from fungi in the soil. The spores become airborne when the ground is disturbed by farming, landscaping, construction or even just by people walking around in fungi-rich environments such as caves. Most healthy adults and children can fight off a fungal infection handily, but infants, older adults and people with compromised immune systems may develop fever, cough, fatigue and other symptoms. Fungal lung infections easily can be mistaken for bacterial or viral lung infections such as COVID-19, bacterial pneumonia and tuberculosis. [...] The researchers calculated the number of fungal lung infections nationwide from 2007 to 2016 using Medicare fee-for-service claims from all 50 states and the District of Columbia. Using the patients’ home addresses to identify counties of residence, they calculated the number of cases per 100,000 person-years for each county. (Person-years are a way to correct for the fact that counties can have wildly different population sizes; one person on Medicare for one year is one person-year). Counties with more than 100 cases caused by Histoplasma or Coccidioides, or 50 cases caused by Blastomyces, per 100,000 person-years were defined as having a meaningful number of fungal lung infections.