Management of disseminated histoplasmosis in a high-complexity clinic in Cali, Colombia

Abstract Histoplasmosis presents a substantial clinical challenge globally, with a particular prevalence in South America, especially among patients with concurrent Human Immunodeficiency Virus (HIV) infection. Despite itraconazole's established efficacy, investigating alternative therapeutic approaches remains imperative. This is the largest study in our region to date, assessing the effectiveness of the less explored posaconazole treatment. This observational study, conducted at Fundación Valle del Lili (FVL) from 2016 to 2022, encompassed adults with disseminated histoplasmosis. Patients (n = 31) were treated with liposomal amphotericin B as an initial treatment, followed by consolidation treatment with posaconazole or itraconazole. Patients with single-organ cases, those lacking microbiological diagnosis, those who received initial treatment with antifungals other than liposomal Amphotericin B and those with < 6 months follow-up were excluded (Figure 1). Analyses considered population characteristics, treatments, and outcomes. Patients (average age: 45.6; 58.1% female) had common comorbidities (HIV 38.7%, solid organ transplantation 29% and oncologic disease 12.9%). Lungs (48.4%) and lymph nodes (16.1%) were commonly affected. Biopsy (64.5%) was the primary diagnostic method. Initial treatment with liposomal amphotericin B (100%) was given for 14 days on average. Follow-up indicated 71% completion with 19.4% requiring treatment modifications. Notably, 70.9% completed a posaconazole consolidation regimen over 350 days on average. Drug interactions during consolidation (80.6%) were common. No relapses occurred, and three deaths unrelated to histoplasmosis were reported. Traditionally, itraconazole has been the prevalent initial treatment; however, in our cohort, 55.9% of patients received posaconazole as the primary option. Encouragingly, posaconazole showed favorable tolerance and infection resolution, suggesting its potential as an effective and well-tolerated alternative for consolidation treatment. This finding prompts further exploration of posaconazole, potentially leading to more effective patient care and better outcomes.