Background:

Contact tracing has been the core strategy for prevention of TB transmission worldwide. Accelerating the detection of disease amongst high-risk contacts for multi-drug resistant tuberculosis (MDR-TB) patients, could maximize the opportunity to prevent disease, by identifying and treating latent infection, and should be prioritised to achieve the End TB strategy.

Methods:

We conducted a cross-sectional survey in Vietnam, consecutive patients with pulmonary MDR-TB with at least one other member in the household from 10 provinces were recruited. We collected the index patients and household contacts (HHC) information including demographics, residential features, history of TB, medical comorbidities, and relationship of contacts with index case. A logistic regression model was developed to determine predictors of TST positivity among HHCs.

Results:

The study identified 1592 MDR-TB cases, 3951 households were enrolled, and the median age was 35 years (interquartile range [IQR]: 32 years). 12 (0.3%) HHCs were HIV- positive, 3775 (95.9%) reported a prior history of TB and 2173 (55.2%) had BCG scar present. Risk factors associated TST positivity among HHCs included lower secondary education (OR = 1.401, 95% CI: 1.18- 1.67), lifelong non-smoker (OR = 7.094, 95% CI:2.128?23.648), and HHC with history of TB (OR = 0.23, 95% CI: 0.137- 0.40).

Conclusion:

HHCs has a high prevalence of TST positivity and at risk of developing TB. Identifying and provide preventive therapy for those at risk of progressing to active TB disease is the key for TB prevention and control.