Pre-entry screening programmes for tuberculosis in migrants to low-incidence countries: a systematic review and meta-analysis.

BACKGROUND Several high-income countries have pre-entry screening programmes for tuberculosis. We aimed to establish the yield of pre-entry screening programmes to inform evidence-based policy for migrant health screening. METHODS We searched six bibliographic databases for experimental or observational studies and systematic reviews, which reported data on migrant screening for active or latent tuberculosis by any method before migration to a low-incidence country. Primary outcomes were principal reported screening yield of active tuberculosis, yield of culture-confirmed cases, and yield of sputum smear for acid-fast bacilli cases. Where appropriate, fixed-effects models were used to summarise the yield of pre-entry screening across included studies. FINDINGS We identified 15 unique studies with data for 3 739 266 migrants screened pre-entry for tuberculosis between 1982 and 2010. Heterogeneity was high for all primary outcomes. After stratification by prevalence in country of origin, heterogeneity was reduced for culture-confirmed and smear-confirmed cases. Yield of culture-confirmed cases increased with prevalence in the country of origin, and summary estimates ranged from 19·7 (95% CI 10·3-31·5) cases identified per 100 000 individuals screened in countries with a prevalence of 50-149 cases per 100 000 population to 335·9 (283·0-393·2) per 100 000 in countries with a prevalence of greater than 350 per 100 000 population. INTERPRETATION Targeting high-prevalence countries could result in the highest yield for active disease. Pre-entry screening should be considered as part of a broad package of measures to ensure early diagnosis and effective management of migrants with active tuberculosis, and be integrated with initiatives that address the health needs of migrants. FUNDING Wellcome Trust, UK National Institute for Health Research, Medical Research Council, Public Health England.