Pulmonary tuberculosis among political asylum seekers screened at Heathrow Airport, London, 1995-9

Background: Over 50% of cases of tuberculosis (TB) in the UK occur in people born overseas, and new entrants to the country are screened for TB. A study was undertaken to determine the prevalence and disease characteristics of pulmonary TB in new entrants to the UK seeking political asylum. Methods: A retrospective analysis of the results of screening 53 911 political asylum seekers arriving at Heathrow Airport between 1995 and 1999 was performed by studying Airport Health Control Unit records and hospital medical records. Outcome measures were chest radiograph abnormalities, sputum smear, culture, and drug resistance data for Mycobacterium tuberculosis. Results: The overall prevalence of active TB in political asylum seekers was 241 per 100 000, There were large variations in prevalences of TB between asylum seekers from different regions, with low rates from the Middle East and high rates from the Indian subcontinent and sub-Saharan Africa. The frequency of drug resistance was high; 22.6% of culture positive cases were isoniazid resistant, 7.5% were multidrug resistant (resistant to both isoniazid and rifampicin), and 4% of cases diagnosed with active disease had multidrug resistant TB. Conclusions: The prevalence rate of TB in political asylum seekers entering the UK through Heathrow Airport is high and more M tuberculosis isolates from asylum seekers are drug resistant than in the UK population. Extrapolating these figures, it is estimated that 101 political asylum seekers with active pulmonary TB enter the UK every year, of whom about 25 would have smear positive disease.