Persistent risk of tuberculosis in migrants, a decade after arrival in Australia

Objective: To examine the risk of tuberculosis (TB) in migrants a decade after their arrival in Australia. Design, setting and patients: Retrospective review of laboratory-confirmed cases of TB in migrants diagnosed between 1990 and 2004 by the state TB reference laboratory in Victoria, analysed by a multivariate model comparing migrants diagnosed 10 or more years after arrival with those diagnosed within 10 years of arrival. Main outcome measures: Time to diagnosis; characteristics of migrants diagnosed with TB, including age, sex, region of birth, site of infection, and drug resistance. Results: A third of migrants (734/1924)were diagnosed with TB 10 or more years after arrival in Australia. This group was more likely to be European-born (adjusted odds ratio [AOR], 3.4; 95% CI, 2.4-5.0) and older than 34 years (35-49 years: AOR, 3.8; 95% CI, 2.0-7.0), reflecting the longer time European migrants have been in Australia. There were two distinct European groups: European Union (EU)/Western and Central/ Eastern. The Central/Eastern group were from countries with current high TB rates and, compared with the EU/Western group, were younger (mean age, 50 v 64 years) and more likely to be diagnosed within 10 years of arrival (47%v 14%; P < 0.001). Conclusion: European migrants were more likely to be diagnosed a decade or more after arrival in Australia. Once migrants from the currently high TB incidence areas of Asia and Africa have been in Australia for a similar period of time, their timing of diagnosis may resemble that for migrants from Europe. The current screening policy should be complemented with more sensitive techniques to detect latent TB.