Contact investigation of tuberculosis in Brunei Darussalam: Evaluation and risk factor analysis

Abstract

Introduction: We evaluated the yield of tuberculosis (TB) contact investigation in Brunei Darussalam, and identified the associated factors for latent TB infection (LTBI) diagnosis, as well as for initiating and completing LTBI treatment. Methods: Data was extracted and digitalised for all close contacts of pulmonary TB cases at the National TB Coordinating Centre from January 2009 to December 2018. Generalising estimating equations (GEE) logistic regression models were used to determine the associated factors. Manual matching against electronic health records system was done to identify contacts who had progressed to active TB disease. Results: Among 10,537 contacts, 9.9% (n= 1047) were diagnosed as LTBI, out of which 43.0% (n= 450) initiated LTBI treatment. Among those who initiated, 74.0% (n= 333) completed LTBI treatment. Contact factors associated with LTBI diagnosis include being male (Adjusted Odds Ratio (aOR)= 1.18 [95%CI: 1.03,1.34), local (aOR= 0.70 [95% CI: 0.56,0.88]), and a household contact. Local LTBI cases had higher odds of initiating LTBI treatment (aOR= 1.86 [95% CI: 1.26,2.73]). Also, LTBI cases detected from local (aOR= 2.32 [95% CI: 1.08,4.97]) and smear positive PTB index cases had higher odds of completing LTBI treatment. Among 1047 LTBI cases, 5 (0.5%) progressed to active PTB within 1-8 years post-LTBI diagnosis. Discussion: LTBI burden is disproportionately high towards foreign nationals, with higher odds of LTBI diagnosis but lower odds of treatment initiation. Establishing digital databases and building TB laboratory capacity for molecular typing would be useful to determine the contribution of LTBI or reactivation towards TB incidence in Brunei.

Epidemiology of Extrapulmonary Tuberculosis in Brunei Darussalam: A retrospective cohort study

“…Another explanation is that it is possible foreign residents may opt to refuse to undergo further diagnostic tests to confirm an EPTB diagnosis due to the monetary costs involved. Similar to the latter countries, Brunei has a significant proportion of foreign residents working in the country, particularly employed as low-skilled workers in construction, wholesale and retail trade (Department of Economic Planning and Statistics Ministry of Finance and Economy Brunei Darussalam 2020; Chaw et al 2022). Foreign workers are required to undergo medical check-up upon start and renewal of their employment contract, and those diagnosed with active TB (PTB or EPTB) would be asked to return to their home country for treatment (Laws of Brunei 2002).…”