Pulmonary Histoplasmosis, Taiwan, 1997–2024

Pulmonary histoplasmosis has traditionally been considered geographically restricted to disease-endemic regions. Taiwan, historically nonendemic, has recently witnessed rising infections. We conducted a retrospective study by reviewing adult patients in Taiwan who had pathologically confirmed pulmonary histoplasmosis during June 1997-December 2024. We analyzed 14 cases with lung involvement. Eight case-patients were male and 6 female; mean age was 56.6 years. Of note, 11 case-patients (78.6%) had no history of travel to histoplasmosis-endemic regions; 10 (71.4%) were immunocompetent. Left upper lobe involvement was most common (n = 4 [28.6%]), with nodular lesions predominating (n = 12 [85.7%]). Most (11 [78.6%]) patients received antifungal therapy, mostly with voriconazole. Outcomes were favorable; 1 (7.1%) patient died. Two additional case-patients without lung involvement exhibited similar demographics and clinical outcomes. Case identification rate has increased since 2015. This 27-year study documents the emergence of pulmonary histoplasmosis in Taiwan, emphasizing the need for heightened clinical suspicion in nonendemic regions.