Advancing the Understanding and Diagnosis of Histoplasmosis: Insights from a Tertiary Care Hospital in India

Background 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. Methods A retrospective study involving adult patients diagnosed with histoplasmosis was conducted at Sir Ganga Ram Hospital, New Delhi, India, from July 2019 to March 2024. Clinical data were extracted from the hospital’s electronic medical records and analysed via SPSS software. Results Eleven patients with a mean age of 48.4 years were identified. The majority were male (90.9%) and had risk factors such as immunosuppressive therapy, HIV (human immunodeficiency virus) and 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%. Discussion Histoplasmosis often mimics tuberculosis (TB) in terms of symptoms and radiological findings, complicating its diagnosis in regions with high TB burdens. Immunosuppressive therapy, HIV, and diabetes are significant risk factors. Clinical presentations vary, including fever, weight loss, and uncommon manifestations like gastrointestinal (GI) and central nervous system (CNS) involvement, posing diagnostic challenges. Unlike those in the western literature, all patients in our study had disseminated histoplasmosis, suggesting the underdiagnosis of milder forms in India. Most patients respond well to intravenous L-AmB (liposomal amphotericin-B) followed by oral itraconazole, although complications such as HLH and MODS are common. The mortality rate was 18.18%, emphasizing the need for timely diagnosis and treatment. Conclusion This study reinforces the importance of heightened clinical suspicion and awareness for diagnosing histoplasmosis. Improved diagnostics with rapid and reliable tests are essential for better patient management and outcomes. Public health strategies should focus on educating healthcare providers about diverse presentations and mandating case notifications. An enhanced understanding of histoplasmosis can mitigate misdiagnosis rates and improve treatment outcomes.