Standard E TB-Feron ELISA and Standard F TB-Feron FIA positivity rates and agreement with QuantiFERON-TB Gold Plus among TB high-risk population in Bandung, Indonesia

Tuberculosis (TB) remains a global public health problem. The determination of tuberculosis infection (TBI) using interferon-gamma release assay has now been used widely. We aim to evaluate the positivity rates of Standard E TB-Feron enzyme-linked immunosorbent assay (TB-Feron ELISA) and Standard F TB-Feron fluorescent immunoassay (TB-Feron FIA) and their agreement with QuantiFERON-TB Gold Plus (QFT-Plus) among TB high-risk populations in Bandung City, Indonesia. We conducted a cross-sectional study, including people with a high risk of acquiring TB. We screened subjects for TB symptoms and offered chest X-ray (CXR). Anyone with cough or CXR suggestive of TB was asked to give sputum samples for GeneXpert MTB/RIF Ultra test. The positivity rates and corresponding 95% confidence intervals (CI) were calculated among patients with bacteriologically confirmed TB and among patients with no evidence of TB, no history of TB, and no known contact with TB patient (low risk of TBI). The agreement with QFT-Plus was calculated using Cohen's κ score. We enrolled 527 subjects, and the proportion of positive results among bacteriologically confirmed TB patients were 8 (53.3%; 95% CI 26.6-78.7), 9 (60.0%, 95% CI 32.3-83.7), and 10 (66.7%, 95% CI 38.4-88.8) by TB-Feron FIA, TB-Feron ELISA and QFT-Plus. The agreement between TB-Feron FIA and QFT-Plus among all subjects was similar to that of TB-Feron ELISA and QFT-Plus (84.1%, κ = 0.66, 95% CI 0.59-0.72). TB-Feron FIA and TB-Feron ELISA showed an acceptable clinical performance compared with QFT-Plus. These tests are useful alternatives for detecting TB infection.IMPORTANCEThis study evaluates the performance of two alternative interferon-gamma release assays, Standard E TB-Feron enzyme-linked immunosorbent assay and Standard F TB-Feron fluorescent immunoassay, for diagnosing tuberculosis infection (TBI) among high-risk populations in Bandung, Indonesia. Both assays demonstrated comparable clinical performance to the widely used QuantiFERON-TB Gold Plus (QFT-Plus). Given the global burden of tuberculosis, particularly in resource-limited settings, these findings suggest that the TB-Feron assays could serve as reliable alternatives to QFT-Plus for TBI detection. This research highlights the potential for these assays to improve tuberculosis diagnosis, offering a more accessible and efficient screening tool, especially for high-risk populations, and supporting broader tuberculosis surveillance.