Mycobacterium Tuberculosis infection among the elderly in 20 486 rural residents aged 50-70 years in Zhongmu County, China.

OBJECTIVES

Elderly individuals in rural China have been known to be at increased risk of contracting tuberculosis (TB) and developing active disease. This study aims to estimate the burden of mycobacterium tuberculosis (MTB) infection and to identify potential targeted subgroups for infection control.

METHODS

As part of the investigation of an interventional study, 50- to 70-year-old rural residents in Zhongmu County were targeted for MTB infection testing using QuantiFERON-TB Gold In-Tube (QFT). Questionnaires and physical examinations were conducted to acquire their demographic information and health status.

RESULTS

A total of 20 486 individuals were included in the analysis. The prevalence of QFT positivity was 20.79% (4259/20 486) and 50 participants (0.24%) had indeterminate results. A positive dose-response relation was found for QFT positivity with smoking intensity. Compared with non-drinkers, the risk of MTB infection was lower among participants with moderate alcohol consumption (<10 g/day) with adjusted odds ratio (OR) of 0.82 (95% CI 0.71-0.94). In addition, gender of male, with a history of previous TB or silicosis, and hepatitis B/C virus infection were associated with increased risk of MTB infection. An indeterminate QFT result was related to being underweight (adjusted OR 3.18; 95% CI 1.09-9.26).

CONCLUSIONS

Our results indicate a high burden of MTB infection among the elderly in this rural area. Smokers, individuals with a history of previous TB or silicosis, and those with hepatitis B/C virus infection should be prioritized for MTB infection control to reduce the risk of disease development from a new infection.