Tuberculosis among newly arrived foreign spouses prior to citizenship in Taiwan: A population-based study

Abstract

Background: Taiwan is a country of tuberculosis medium-burden with 70% of TB patients aged over 50, Taiwan's immigrant TB control policy primarily aims to identify active TB cases. Foreign workers are screened prior to entry into Taiwan; if those who are TB positive, they are not allowed to enter inti or remain in Taiwan. However, foreign spouses are excluded from this prohibition. This study is intended to estimate the tuberculosis burden among new foreign spouses, predominantly those aged under 50 and their derlying close contacts in Taiwan, 2006-2011. Methods & Materials: By analysis a nationwide surveillance database, we assessed the TB burden via a 6-year population-based study. The TB relative risk of TB among foreign spouses within newly arrived (within4-6 years) foreign spouses vs. indigenous persons and the TB prevalence among subordinate underlying close contacts of TB index cases was assessed. Results: 94.0% (721/768) of new foreign spouses with Tuberculosis (TB), of whom 98.6% were female, had come from South-East Asia nations (Vietnam, Indonesia, Philippines and Thailand) or China. TB rates (40.3-176.2 per 105/year) among newly emigrant wives aged 20-49 were 1.7- to 7.3-fold higher than those of Taiwanese females of corresponding ages. Additionally, TB prevalence among the 2,698 close contacts of 768 foreign-spouse index cases was 1.2% via a 2-year-follow-up based investigation. In terms of laboratory diagnostics, 87.2% (675/768) or 11.1% (85/768) of all TB cases diagnosed as abnormal radiographs or normal radiographs were later diagnosed as encompassing negative-smear combined with positive-culture of 35.4% (239/675) or 14.1% (12/85) as well as positive-smear combined with positive-culture of 29% (196/675) or 2.3% (2/85), respectively. Conclusion: Foreign wives from high TB endemic countries and their close contacts, including underlying household or cohabitants, had a relatively high TB risk. Active TB screening via health examination by chest autoradiography should be performed as early as possible, rather than be delayed until prior to apply for citizenship is recommended. Furthermore, we reconsider that applying a more sensitive point-of-care test for TB could facilitate rapid screening and diagnosis for those TB cases with normal radiographs or who are smear negative combined with culture positive.