Understanding Histoplasmosis and a Tennessee Cluster

In late 2025 health authorities noted an unusual rise in histoplasmosis cases in a stretch of Middle Tennessee that includes Spring Hill and Thompson's Station, communities that lie along the border of Williamson and Maury counties. Investigators have identified at least 18 confirmed infections, while some public briefings have cited higher totals and the search for specific exposure sites is ongoing.

Histoplasma capsulatum is a soil-dwelling fungus that thrives where bird or bat droppings accumulate, and it produces microscopic spores that can become airborne when contaminated soil or structures are disturbed. Infection follows inhalation of those spores during demolition, land clearing, renovation, or cleanup of roosting sites; most exposures cause mild or no symptoms, but the illness can progress to pneumonia or disseminated disease in people with weakened immune systems.

Diagnosis is supported by urine antigen testing and by fungal culture, although cultures may require several weeks to yield a result; public health laboratories have been notified and specimens have been forwarded for testing. Clinicians decide treatment based on severity: mild acute infections may be observed, moderate disease is treated with oral itraconazole, and severe or life-threatening infections are treated with amphotericin B.

Local reports have described one death among people who tested positive for histoplasmosis, but investigators have not confirmed the infection as the cause of death. To reduce risk, workers and homeowners should avoid disturbing soil contaminated with bird or bat droppings, use appropriate respiratory protection when dust is likely, and seek medical care if respiratory symptoms persist after potential exposure.