Scaling-up tuberculosis preventive therapy to over five-years old HIV-negative contacts of bacteriologically confirmed TB cases - lessons from a tuberculosis preventive therapy surge activity in Zambia

BackgroundWhile tuberculosis preventive therapy (TPT) coverage among people living with HIV in Zambia has improved, uptake among HIV-negative contacts aged [≥]5 years remains low. Despite some evidence that TPT can reduce TB incidence by up to 60% in HIV-negative individuals, there is a paucity of evidence on programmatic rollout to this population in Zambia and the region. We present programme data from a TPT surge aimed at increasing uptake among [≥]5 years old HIV-negative household TB contacts. MethodsThe National TB Programme, with support from the TB Local Organizations Network, conducted a TPT surge in 89 high TB-burden facilities across eight project supported provinces in Zambia from October 2024 to 15th January 2025. After a thorough planning phase, multidisciplinary teams conducted field visits for contact tracing and initiated TPT for eligible household contacts of bacteriologically confirmed TB, regardless of HIV status or age. Facility-based TPT initiation was provided for walk-in clients. We collected aggregate data from facility registers and analyzed it descriptively. ResultsA total of 21,890 HIV-negative contacts were screened: 21,482 (98.1%) eligible for TPT. Among these, 15,711(74.6%) were initiated on TPT. Of those screened, 19,607 (91.8%) were >5 years old; 19,345(98.7%) of them were eligible, and 14,000 (72.4%) were initiated on TPT. Overall, 61.2% (n=9432) were initiated on three months Isoniazid + Rifapentine, followed by six months Isoniazid(32.6%, n=5125); one month Isoniazid and Rifapentine (4.1%, n=638) and on three months Isoniazid and Rifampicin (1.7%, n=272). ConclusionThe Surge demonstrated that high TPT coverage among [≥]5 years old HIV-negative TB contacts is achievable with targeted implementation, stakeholder engagement, and community-driven approaches. These findings underscore the importance of expanding routine tuberculosis preventive therapy delivery to include all high-risk contacts, regardless of HIV status or age, to accelerate TB prevention efforts in high-burden settings like Zambia.