Hidden fungal disease after TB in Senegal needs attention

Chronic Pulmonary Aspergillosis (CPA) is a lung condition that can follow pulmonary tuberculosis (TB), but it is often overlooked, especially where laboratory resources are limited. In Senegal, there has been no prior data on how common Aspergillus infection is among people who have had TB. To fill that gap, a team led by corresponding author Aïda Sadikh Badiane carried out a cross-sectional serological screening at two health centers, Wakhinane and Yeumbeul, among patients with a history of TB and ongoing respiratory symptoms. Each person in the study gave a blood sample that was tested for antibodies against Aspergillus using two approaches: an Enzyme-Linked Immunosorbent Assay (ELISA) and a Rapid Diagnostic Test (RDT). Results from the tests were recorded as positive, negative, invalid, or not tested, and the researchers analyzed valid results to estimate how common Aspergillus antibodies were and how well the two tests agreed. The study was designed to measure seroprevalence in this post-TB group and to evaluate whether a simple RDT could serve as a practical screening tool compared with ELISA-based testing.

The study tested blood samples with both ELISA and a Rapid Diagnostic Test (RDT) and reported findings using the valid results only. Overall, ELISA found antibodies in 11.9% of samples (38 out of 320), while the RDT was positive in 5.5% (11 out of 200). Results varied by site: for RDT positivity Wakhinane exceeded Yeumbeul (4.5% vs. 1.0%), whereas ELISA positivity was higher at Yeumbeul than Wakhinane (13.5% vs. 11.2%). The screened group was mostly male (66.0%) with a median age of 30 years. The team also used ROC analysis on the ELISA results to identify an optimal threshold that balanced test performance; at that threshold the ELISA showed 78% sensitivity and 89% specificity. Taken together, the higher positivity by ELISA suggests greater sensitivity compared with the RDT, while the RDT’s ease of use points to its potential for initial screening in peripheral clinics where full laboratory testing is not available.

These findings provide the first serological evidence that Aspergillus antibodies are present at substantial levels among people who have had TB in Senegal, implying there may be a significant burden of undiagnosed CPA. For clinicians and health systems in West Africa, the study highlights two practical points: ELISA testing, with higher sensitivity and a defined threshold, is important for surveillance and confirmation of suspected CPA, while a Rapid Diagnostic Test can be a pragmatic option for initial screening at clinics without laboratory capacity. Integrating CPA screening into routine post-TB care could help identify patients who need further investigation or treatment, and strengthening fungal diagnostic capacity would allow more accurate diagnosis and tracking of the condition. The site differences in positivity rates also suggest local factors or referral patterns may influence detection, underscoring the need for broader surveillance and training so CPA does not remain hidden after TB treatment.