Active tuberculosis cases in migrants in Newham: should we extend screening criteria for latent tuberculosis infection

Background: The collaborative tuberculosis strategy 2015-2020 published by Public Health England (PHE) currently recommends screening all migrants aged 16-35 who entered the UK less than 5 years ago arriving from a high incidence country (≥150/100,000 or Sub-Saharan Africa (SSA)). Methods: A retrospective analysis of all active TB cases notified in Newham 2011-2016. We evaluated the number of active cases in migrants from high incidence countries or SSA which may have been prevented by screening using the PHE criteria, and with extended criteria (age 16-50, and up to 10 and 15 years in the UK). Results: A total of 1409 cases were notified in Newham from 2011 to 2016. 923 were male, 485 were female. Of these, 1092 came from countries eligible for screening under PHE guidelines (incidence ≥150/100,000, or SSA). 369 of these active cases fulfilled the additional PHE criteria for age and years since UK entry, and could potentially have been prevented by the screening programme. With all other parameters kept constant, extending screening to those up to the age of 50 may have prevented an additional 51 cases. 152 cases may have been prevented by extending screening to those who had been in the country for up to 10 years. Conclusion: Further work is needed to evaluate whether current LTBI screening guidelines should be extended to migrants up to 50 years or who have been in the UK more than 5 years. Figure 1: Active TB cases in eligible migrants that may have been prevented under different screening protocols.