Screening and diagnostic strategies for active pulmonary tuberculosis among people in prison in Malaysia: a prospective diagnostic study

Background The World Health Organization (WHO) recommends tuberculosis (TB) screening in prisons but data on specific strategies are lacking. Methods Men sequentially entering Kajang Prison, Malaysia's largest prison, underwent standardized WHO symptom screening (SS), chest X-ray (CXR), and c-reactive protein (CRP ≥5 mg/L) screening tests while acid-fast bacilli (AFB) smears and Xpert were diagnostic tests. The reference standard was culture. We defined three screening strategies and compared their sensitivity, specificity, positive predictive value, negative predictive value, receiver operator curves, and area under the curve (AUC). Findings We enrolled 588 people in prison, mean age 43 (range: 21-68) years, 60 (10.2%) with HIV, 493 (83.8%) with opioid use disorder, and 265 (45.1%) with HCV. Among these, 34 (5.8%) were diagnosed with culture-positive active pulmonary TB (PTB). For screening, the sensitivity of SS, CRP ≥5 mg/L, and CXR demonstrating PTB was 38.2% (95% CI 22.2-56.4), 47.1% (95% CI 29.8-64.9), and 91.2% (95% CI 76.3-98.1). Among people without HIV, "SS-CXR" had the highest AUC (74.7% [95% CI 68.6-80.7]). For people with HIV, however, "SS-CRP" had the highest AUC (85.5% [95% CI 79.4-91.5]). For diagnosis, Xpert had a higher sensitivity (82.4% [95% CI 65.5-93.2] and specificity (95.5% [95% CI 93.4-97.1]) than AFB smear. Compared to "SS-Xpert", both "SS-CXR-Xpert" and "SS-CRP-Xpert" had a significantly higher AUC in people without HIV (84.2% p Interpretation Among people in prison, adding CXR or CRP to symptom screen was more effective than symptom screen alone. In addition to symptom screen, CRP performed better than CXR among people with HIV while CXR was more valuable than CRP among people without HIV. Funding U.S. National Institute on Drug Abuse.