Outcomes analysis of new entrant screening for active tuberculosis in Heathrow and Gatwick airports, United Kingdom 2009/2010.
BACKGROUND
In 2012, the United Kingdom (UK) Government announced that the new entrant screening for active tuberculosis (TB) in Heathrow and Gatwick airports would end. Our study objective was to estimate screening yield and diagnostic accuracy, and identify those at risk of active TB after entry.


METHODS
We designed a retrospective cohort study and linked new entrants screened from June 2009 to September 2010 through probabilistic matching with UK Enhanced TB Surveillance (ETS) data (June 2009 to December 2010). Yield was the proportion of cases reported to ETS within three months of airport screening in the screened population. To estimate screening diagnostic accuracy we assessed sensitivity, specificity, positive and negative predictive values. Through Poisson regression we identified groups at increased risk of TB diagnosis after entry.


RESULTS
We identified 200,199 screened entrants, of these 59 had suspected TB at screening and were reported within 3 months to ETS (yield = 0.03 %). Sensitivity was 26 %; specificity was 99.7 %; positive predictive value was 13.2 %; negative predictive value was 99.9 %. Overall, 350 entrants were reported in ETS. Persons from countries with annual TB incidence higher than 150 cases per 100,000 population and refugees and asylum seekers were at increased risk of TB diagnosis after entry (population attributable risk 77 and 3 % respectively).


CONCLUSIONS
Airport screening has very low screening yields, sensitivity and positive predictive value. New entrants coming from countries with annual TB incidence higher than 150 per 100,000 population, refugees and asylum seekers should be prioritised at pre- or post-entry screening.
European Programme for Intervention Epidemiology Training (EPIET), European Centre for Disease Prevention and Control, Stockholm, 17183, Sweden.|Health Protection Agency (HPA), London, SW1W 9SZ, UK.|Present address: European Centre for Disease Prevention and Control, Surveillance and Response Support Unit, Stockholm, 17183, Sweden.
Ettore
E
Severi
European Programme for Intervention Epidemiology Training (EPIET), European Centre for Disease Prevention and Control, Stockholm, 17183, Sweden.|Health Protection Agency (HPA), London, SW1W 9SZ, UK.
Helen
H
Maguire
Health Protection Agency (HPA), London, SW1W 9SZ, UK.
Chikwe
C
Ihekweazu
Health Protection Agency (HPA), London, SW1W 9SZ, UK.
Graham
G
Bickler
University College London, Centre for Infectious Disease Epidemiology, London, WC1E 6BT, UK. Ibrahim.Abubakar@phe.gov.uk.|Health Protection Agency, Colindale, NW9 5EQ, UK. Ibrahim.Abubakar@phe.gov.uk.
Ibrahim
I
Abubakar
D000293:Adolescent; D000328:Adult; D000368:Aged; D059028:Airports; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D012036:Refugees; D012189:Retrospective Studies; D012306:Risk; D012680:Sensitivity and Specificity; D014376:Tuberculosis / Q000175:diagnosis / Q000453:epidemiology*; D006113:United Kingdom / Q000453:epidemiology; D055815:Young Adult
Communicable diseases; Diagnostic accuracy; Immigration; Respiratory tract diseases; Tuberculosis