Magnitude and associated factors of latent tuberculosis infection due to Mycobacterium tuberculosis complex among high-risk groups in urban Bobo-Dioulasso, Burkina Faso.

OBJECTIVES

To determine the prevalence and risk factors for latent tuberculosis infection (LTBI) among three high-risk groups - household contacts of TB index cases, healthcare workers and slaughterhouse workers - in Bobo-Dioulasso, Burkina Faso.

METHODS

Participants were recruited to this cross-sectional study from March to July 2020 after giving informed consent. Sociodemographic, clinical and biological data were collected using a structured questionnaire. The QuantiFERON-TB Gold Plus test (QFT-Plus) and the tuberculin skin test (TST) were used for detection of LTBI. Bivariate and multivariate logistic regression analyses were performed to identify risk factors for LTBI.

RESULTS

The prevalence of LTBI among 101 participants (age range 15-68 years) was 67.33% [95% confidence interval (CI) 57.27-76.33] and 84.16% (95% CI 75.55-90.66) based on QFT-Plus and TST results, respectively. Compared with healthcare workers and household contacts of TB index cases, the prevalence of LTBI among slaughterhouse workers was significantly higher for both QTF-Plus (96.8%; P<0.001) and TST (100%; P=0.003). Working in a slaughterhouse [adjusted odds ratio (AOR) 1.095, 95% CI 1.00-2.036], smoking (AOR 4.214, 95% CI 1.051-16.899), ≥15 years of exposure (AOR 5.617, 95% CI 1.202-32.198), having an animal at home (AOR 2.735, 95% CI 1.102-6.789) and protozoal infection (AOR 2.591, 95% CI 1.034-6.491) were significantly associated with LTBI on the QFT-Plus assay.

CONCLUSION

The prevalence of LTBI was high in all three groups, particularly slaughterhouse workers. The risk factors identified could form the basis of targeted intervention.