Seroprevalence Screening of Chronic <i>Aspergillus</i> Infection in a Post‐Tuberculosis Cohort in Senegal: A Cross‐Sectional Study Comparing <scp>ELISA</scp> and Rapid Diagnostic Tests

BACKGROUND: Chronic pulmonary aspergillosis (CPA) is a significant, yet often overlooked, sequela of pulmonary tuberculosis (TB), particularly in resource-limited settings. Data on the seroprevalence of Aspergillus infection in Senegal is absent, and diagnostic capacity is limited. This study aimed to determine the seroprevalence of Aspergillus-specific antibodies among patients with a history of TB in Senegal and to evaluate the performance of a Rapid Diagnostic Test (RDT) against an Enzyme-Linked Immunosorbent Assay (ELISA). METHODS: A cross-sectional study was conducted between April 30 to August 31, 2025 at two health centers in Senegal: Wakhinane and Yeumbeul among patients presenting with chronic respiratory symptoms. After obtaining informed consent from adult participants or from parents/guardians for minors, a blood sample was collected from each participant and tested for Aspergillus antibodies using both a rapid diagnostic test (RDT) and an ELISA. Results were classified as positive, negative, invalid, or not tested. Prevalence and agreement between the two assays were calculated using valid results only. Demographic data were collected, and descriptive statistics with test performance analyses were conducted. RESULTS: The overall seroprevalence was significantly higher by ELISA (11.9%; 38/320) than by RDT (5.5%; 11/201). Site-specific analysis revealed disparities: Wakhinane showed higher RDT positivity (4.5% vs. 1.0%), while Yeumbeul had higher ELISA positivity (13.5% vs. 11.2%). The cohort was predominantly male (66.0%) with a median age of 30 years. ROC analysis of the ELISA identified an optimal threshold that balanced sensitivity (78%) and specificity (89%). CONCLUSION: This study provided the first serological evidence of substantial Aspergillus antibody prevalence among post-TB patients in Senegal, suggesting a significant burden of undiagnosed CPA. The higher sensitivity of ELISA makes it essential for surveillance and confirmation, while the RDT's practicality offers a viable option for initial screening in peripheral clinics. These findings underscored the urgent need to integrate CPA diagnosis into routine post-TB care and to strengthen fungal diagnostic capacity in West Africa.