title: Pre-entry screening programmes for tuberculosis in migrants to low-incidence countries: a systematic review and meta-analysis.
abstract: 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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
  
  
  BACKGROUND
  Wellcome Trust, UK National Institute for Health Research, Medical Research Council, Public Health England.
authors.affiliation: Research Department of Infection and Population Health, University College London, London, UK. Electronic address: rob.aldridge@gmail.com.
authors.forename: Robert W
authors.initials: RW
authors.lastname: Aldridge
authors.affiliation: Research Department of Infection and Population Health, University College London, London, UK.
authors.forename: Tom A
authors.initials: TA
authors.lastname: Yates
authors.affiliation: Research Department of Infection and Population Health, University College London, London, UK; TB Section, Public Health England, London, UK.
authors.forename: Dominik
authors.initials: D
authors.lastname: Zenner
authors.affiliation: Modelling and Economics Unit, Centre for Infectious Disease Surveillance and Control, Public Health England, London, UK; MRC Centre for Outbreak Analysis and Modelling and NIHR Health Protection Research Unit in Modelling Methodology, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, UK.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: White
authors.affiliation: Research Department of Infection and Population Health, University College London, London, UK; TB Section, Public Health England, London, UK.
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Abubakar
authors.affiliation: Research Department of Infection and Population Health, University College London, London, UK.
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Hayward
mesh_terms: D006801:Humans; D015994:Incidence; D008403:Mass Screening / Q000379:methods*; D014171:Transients and Migrants; D014376:Tuberculosis / Q000175:diagnosis*