Histoplasmosis in non-immunosuppressed patients from an endemic area in Northeastern Brazil

Abstract

Differently from immunocompromised patients, very little information is available in the literature regarding the clinical presentation, epidemiology, and outcomes of histoplasmosis in non-immunosuppressed individuals living in endemic areas. This retrospective case series study was carried out by reviewing the medical records of non-immunocompromised patients with histoplasmosis, residents in a hyperendemic area in northeastern Brazil, between 2011 and 2022. Thirty HIV-negative patients were identified with histoplasmosis, and 19 cases met the inclusion criteria: ten patients had acute pulmonary histoplasmosis (APH), one had chronic pulmonary histoplasmosis (CPH), two had progressive disseminated (PD) presentation, and six had the chronic disseminated (CD) form. The median age of our sample was 32.7 years old [IQR: 24 - 45]. Most of the patients were male (male-to-female ratio=15:4) and resided in the state capital (n=9). The majority had a previous history of exposure to well-known risk factors for Histoplasma infection. The lung images of APH were characterized by nodules, enlarged hilar/mediastinal lymph nodes, and patches, and three patients were initially treated empirically for pulmonary tuberculosis; one death was registered. The chronic pulmonary form of histoplasmosis was diagnosed in one patient only after the symptoms persisted despite specific treatment. The primary clinical manifestations of the CD form were enlarged lymph nodes, with histopathology being the main diagnostic method. The cases were detected as isolated occurrences and not as an outbreak, suggesting that exposure to Histoplasma can be more widespread than presumed. Despite the self-limiting nature of the disease, death can occur even in previously heath patients.