Comparing Active and Passive TB Contact Investigation Approaches: Evidence from Northeast Nigeria

Background: Household contacts (HHCs) of pulmonary TB patients in Northeast Nigeria face high infection risk. We compared active versus passive contact investigation strategies in this high-burden setting. Methods: A randomized study (July-Dec 2022) assigned 165 index patients per arm across 4 facilities in Adamawa/Yobe States. Active arm: Health workers conducted home visits for symptom screening. Passive arm: HHCs self-presented to clinics. Presumptive TB cases underwent GeneXpert testing; Bac+ cases received treatment, others referred. Results: Among 982 active-arm HHCs, 93% (913) were screened, compared to 99% (842/851) of passive-arm HHCs. Presumptive TB was higher in the passive arm (281 vs. 221). Case yields showed Bac+ TB was similar (Active: 29, Passive: 32), while all TB forms were slightly higher in the active arm (40 vs. 36), including more children <5 (9 vs. 4). Active screening yielded more DR-TB (5 vs. 2) and linked more HIV+ contacts to care (12 vs. 5). Conclusion: Passive strategy achieved higher screening coverage, but active strategy detected more clinically diagnosed children<5 (9 vs 4), DR-TB (5 vs 2), and HIV co-infections (12 vs 5). Active home visits are critical for finding vulnerable cases in Northeast Nigeria.