Eliminating latent tuberculosis in low-burden settings: are the principal beneficiaries to be disadvantaged groups or the broader population?

Tuberculosis (TB) remains a leading cause of morbidity and mortality worldwide, and the burdens of this disease continue to track prior disadvantage. In order to galvanise a coordinated global response, WHO has recently launched the End TB Campaign that aims to eliminate TB by 2050. Key to this is the introduction of population screening programmes in low-burden settings to identify and treat people who have latent TB infection (LTBI). The defining features of LTBI are: that it is not an active disease but confers an increased risk of disease; the socially disadvantaged are those most in danger and uncertainty persists as to who will be harmed or benefitted from screening-led prophylactic interventions. Systematic screening programmes that include surveillance, case-finding and treatment of asymptomatic individuals inevitably redistribute the risk of harms and the potential for benefits within a population. The extent to which those targeted within such programmes should be exposed to higher levels of risk in the pursuit of individual or community benefits requires careful consideration prior to implementation. As currently construed, it remains unclear who stands to benefit most from how LTBI screening in high-income countries is being organised, and whose health is being prioritised: members of disadvantaged groups or the broader community. Unless the aims of LTBI screening programmes in these settings are made transparent and their prioritisation ethically justified, there is a significant danger that such a targeted intervention will further disadvantage those who have the least capacity to bear the burdens of TB elimination.