Abstract:

Tuberculosis (TB) contact investigation is a key strategy recommended by the World Health Organisation (WHO) to help detect cases early, increase preventive treatment, and reduce TB transmission. Even though many countries have adopted these policies, putting them into practice is still limited in places with high TB rates. This review brings together global evidence and highlights important areas such as how programs are run, what works well, ongoing challenges, and where more research is needed. The review covers thirty studies from different settings, including household and community interventions, digital tools, programs led by community health workers, public–private partnerships, and integrated service models. TB contact investigation has been effective in finding more cases and increasing preventive treatment. Household-based strategies work well but have not been widely expanded. Using community contact clusters could help find more cases in high-burden areas, but this can require a lot of resources. Digital tools might make the process more efficient and improve data quality if they are adapted to local needs. Programs led by community health workers can reach more people, but they often cost a lot to run. Expanding TB contact investigation can help with early detection and prevention if enough resources are provided. However, there are still many operational, social, and health system barriers that make it hard to implement these programs widely. To put the evidence into practice, ongoing investment, stronger health systems, local adaptation, and real involvement of affected communities are needed.

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