Curvilinear pattern of pulmonary tuberculosis among migrant workers entering Kuwait: 1997-2006

Background: There is paucity of published data on the pattern of tuberculosis among immigrants entering Middle Eastern countries. The objectives of this study were to use routine health surveillance data to i) to estimate the prevalence of pulmonary tuberculosis to migrant workers to Kuwait and ii) to determine the occurrence of any time trends in the proportions of pulmonary tuberculosis positive workers over the study period. Methods: Monthly aggregates of number tested and pulmonary tuberculosis positive diagnosis results obtained from routine health examinations of migrants from tuberculosis high-prevalence countries conducted between January 1, 1997 and December 31, 2006, were analysed using time series methods. Results: Overall prevalence (per 100,000) of pulmonary tuberculosis positive migrants was 198 (4608/2328582). Year-specific tuberculosis positive (per 100,000) cases consistently declined from 456 (95% CI: 424 490) in 1997 to 124 (95% CI: 110 140) in 2002 before showing a steady increase till 2006. The second-order polynomial regression model revealed significant (P < 0.001) initial decline followed by a significant (P < 0.001) increasing trend thereafter in monthly proportions of tuberculosis positive migrants. Conclusion: The significant increasing trend in tuberculosis cases towards the end of the study period, underscore the need to maintain the current policy of screening of migrants from tuberculosis endemic countries using improved diagnostic protocol combined with treatment, to ensure that the risk of local M. tuberculosis transmission is minimized.