Prevalence of histoplasmosis in Nigerian children with presumptive tuberculosis: a multicentre study comparing two diagnostic techniques

Abstract

Data from studies conducted on histoplasmosis in Nigeria are mostly from the adult age group with sparse information about its occurrence in our paediatric population. Histoplasmosis, often overlooked in tropical paediatric populations, is a critical differential diagnosis in regions with a high tuberculosis (TB) burden, especially in low- and middle-income countries (LMIC). In addition, case series from Nigeria show histoplasmosis is commonly misdiagnosed as TB in paediatric population. This study investigated Nigerian children with presumptive TB for histoplasmosis using Histoplasma antigen assay. This was a descriptive cross-sectional study conducted across paediatric TB clinics in three sites in Nigeria, namely, Uyo, Ibadan, and Calabar. One hundred participants were recruited; 73 were unconfirmed cases of TB, 27 were confirmed TB cases, while 21 were participants with advanced HIV disease. The urine samples were assayed for the detection of Histoplasma antigen using the MiraVista lateral flow assay (MVD LFA) and Clarus IMMY ELISA. Of the 100 sampled participants, two participants tested positive for Histoplasma antigen with MVD LFA, while none were positive with ELISA. Notably, these individuals were unconfirmed cases of TB. Paediatric histoplasmosis is not an uncommon finding in Nigerian children presenting with symptoms mimicking TB. The findings highlight the urgent need for cost-effective, accessible diagnostics in resource-limited settings to improve paediatric care, with further research required for the validation of Histoplasma antigen assay diagnostics in children.

Keywords: Histoplasma antigen; TB; children; diagnostic assay; histoplasmosis.