Histoplasmosis in India: clinical insights from a tertiary care hospital

Histoplasma capsulatum, a dimorphic fungus, is a significant cause of endemic mycosis, particularly in immunocompromised individuals. While considered endemic to the Gangetic Plains in India, reports from nonendemic regions have been increasing. This study aims to enhance the understanding and diagnosis of histoplasmosis by describing cases from a tertiary care hospital in New Delhi, India. A retrospective study involving adult patients diagnosed with histoplasmosis was conducted at Sir Ganga Ram Hospital, New Delhi, India, from 1st July 2019 to 31st March 2024. Clinical data were extracted from the hospital’s electronic medical records and analysed. Eleven patients with a mean age of 48.4 years were identified. Of the patients, 10 (90.9%) were male. Except for one patient, all had identifiable risk factors such as immunosuppressive therapy, HIV (human immunodeficiency virus), or diabetes. Common symptoms included fever (90.9%) and weight loss (72.7%). Hematological abnormalities such as anemia and leukopenia (36.3%) and radiological findings of splenomegaly (72.7%) and hepatomegaly (63.6%) were most common. Complications such as hemophagocytic lymphohistiocytosis (HLH) and multiple organ dysfunction syndrome (MODS) occurred in 27.2% of patients, with a mortality rate of 18.18%. Our study highlights that, in India, histoplasmosis is frequently detected in its advanced disseminated form, particularly among immunocompromised patients, rather than at an early acute pulmonary stage. This delay is compounded by its clinoco-radiological resemblance to infections like tuberculosis and the limited availability of rapid diagnostic tools, often requiring invasive procedures. An enhanced understanding of histoplasmosis could help mitigate misdiagnosis and lead to better treatment outcomes. These findings call for increased clinical awareness amongst clinicians and early screening in at-risk groups, supported by expanded research to strengthen epidemiological data and establish clear diagnostic guidelines.