The Lancet
Volume 388, Issue 10059, 2016, Pages 2510-2518

Tuberculosis in migrants moving from high-incidence to low-incidence countries: a population-based cohort study of 519 955 migrants screened before entry to England, Wales, and Northern Ireland (Article) (Open Access)

Aldridge R.W.* , Zenner D. , White P.J. , Williamson E.J. , Muzyamba M.C. , Dhavan P. , Mosca D. , Thomas H.L. , Lalor M.K. , Abubakar I. , Hayward A.C.
  • a Centre for Public Health Data Science, Institute of Health Informatics, University College London, London, United Kingdom, Farr Institute of Health Informatics Research, University College London, London, United Kingdom, Institute for Global Health, University College London, London, United Kingdom, Centre for Infectious Disease Surveillance and Control, Public Health England, London, United Kingdom
  • b Institute for Global Health, University College London, London, United Kingdom, Centre for Infectious Disease Surveillance and Control, Public Health England, London, United Kingdom
  • c Centre for Infectious Disease Surveillance and Control, Public Health England, London, United Kingdom, MRC Centre for Outbreak Analysis and Modelling and NIHR Health Protection Research Unit in Modelling Methodology, Imperial College London, London, United Kingdom
  • d Farr Institute of Health Informatics Research, University College London, London, United Kingdom
  • e Institute for Global Health, University College London, London, United Kingdom, Centre for Infectious Disease Surveillance and Control, Public Health England, London, United Kingdom
  • f Migration Health Division, International Organization for Migration, Geneva, Switzerland
  • g Migration Health Division, International Organization for Migration, Geneva, Switzerland
  • h Institute for Global Health, University College London, London, United Kingdom, Centre for Infectious Disease Surveillance and Control, Public Health England, London, United Kingdom
  • i Institute for Global Health, University College London, London, United Kingdom, Centre for Infectious Disease Surveillance and Control, Public Health England, London, United Kingdom
  • j Institute for Global Health, University College London, London, United Kingdom, Centre for Infectious Disease Surveillance and Control, Public Health England, London, United Kingdom
  • k Centre for Public Health Data Science, Institute of Health Informatics, University College London, London, United Kingdom, Farr Institute of Health Informatics Research, University College London, London, United Kingdom

Abstract

Background Tuberculosis elimination in countries with a low incidence of the disease necessitates multiple interventions, including innovations in migrant screening. We examined a cohort of migrants screened for tuberculosis before entry to England, Wales, and Northern Ireland and tracked the development of disease in this group after arrival. Methods As part of a pilot pre-entry screening programme for tuberculosis in 15 countries with a high incidence of the disease, the International Organization for Migration screened all applicants for UK visas aged 11 years or older who intended to stay for more than 6 months. Applicants underwent a chest radiograph, and any with results suggestive of tuberculosis underwent sputum testing and culture testing (when available). We tracked the development of tuberculosis in those who tested negative for the disease and subsequently migrated to England, Wales, and Northern Ireland with the Enhanced Tuberculosis Surveillance system. Primary outcomes were cases of all forms of tuberculosis (including clinically diagnosed cases), and bacteriologically confirmed pulmonary tuberculosis. Findings Our study cohort was 519 955 migrants who were screened for tuberculosis before entry to the UK between Jan 1, 2006, and Dec 31, 2012. Cases notified on the Enhanced Tuberculosis Surveillance system between Jan 1, 2006, and Dec 31, 2013, were included. 1873 incident cases of all forms of tuberculosis were identified, and, on the basis of data for England, Wales, and Northern Ireland, the estimated incidence of all forms of tuberculosis in migrants screened before entry was 147 per 100 000 person-years (95% CI 140–154). The estimated incidence of bacteriologically confirmed pulmonary tuberculosis in migrants screened before entry was 49 per 100 000 person-years (95% CI 45–53). Migrants whose chest radiographs were compatible with active tuberculosis but with negative pre-entry microbiological results were at increased risk of tuberculosis compared with those with no radiographic abnormalities (incidence rate ratio 3·2, 95% CI 2·8–3·7; p<0·0001). Incidence of tuberculosis after migration increased significantly with increasing WHO-estimated prevalence of tuberculosis in migrants' countries of origin. 35 of 318 983 pre-entry screened migrants included in a secondary analysis with typing data were assumed index cases. Estimates of the rate of assumed reactivation tuberculosis ranged from 46 (95% CI 42–52) to 91 (82–102) per 100 000 population. Interpretation Migrants from countries with a high incidence of tuberculosis screened before being granted entry to low-incidence countries pose a negligible risk of onward transmission but are at increased risk of tuberculosis, which could potentially be prevented through identification and treatment of latent infection in close collaboration with a pre-entry screening programme. Funding Wellcome Trust, UK National Institute for Health Research, UK Medical Research Council, Public Health England, and Department of Health Policy Research Programme. © 2016 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY license

Author Keywords

[No Keywords available]

Index Keywords

Wales Northern Ireland England tuberculosis cohort analysis Transients and Migrants Incidence human Humans migration Cohort Studies
Link
https://www.scopus.com/inward/record.uri?eid=2-s2.0-84996536706&doi=10.1016%2fS0140-6736%2816%2931008-X&partnerID=40&md5=02e254e1f754cc14e40de4345df7c098
DOI: 10.1016/S0140-6736(16)31008-X
ISSN: 01406736
Cited by: 47
Original Language: English