Disseminated histoplasmosis diagnosed by mNGS in a middle-aged immunocompetent patient: a case report and literature review

Histoplasmosis is a fungal infection caused by the dimorphic fungus Histoplasma capsulatum . Its clinical presentation is highly variable, ranging from asymptomatic cases to progressive disseminated infections. Disseminated histoplasmosis is the rarest form and is mostly found in immunocompromised patients, although rare cases have also been reported among immunocompetent individuals. In this study, we present a case of disseminated histoplasmosis in a middle-aged, immunocompetent patient from Sichuan Province, southwest China, diagnosed by mNGS. This condition is rarely documented in this region, and its diverse, non-specific clinical manifestations often lead to misdiagnosis. This atypical case highlights the challenges associated with the early recognition and diagnosis of disseminated histoplasmosis in immunocompetent patients presenting with non-specific symptoms. Additionally, we reviewed cases of histoplasmosis reported in immunocompetent individuals between 2021 and 2025. This information may serve as a reference for clinicians in the management of this uncommon disease.