Prevalence and incidence of latent tuberculosis infection among healthcare workers in chest diseases hospitals, Bangladesh: putting infection control into context

Mr Md Saiful Islam¹, Emily S  Gurley, Sayera  Banu, Kamal  Hossain, James D Heffelfinger, Kamal Ibne Amin Chowdhury, Shahriar  Ahmed, Sadia  Afreen, Sayed Mohammad Mazidur Rahman, Michelle L  Pearson, Shua J Chai

¹Australian National University, Canberra ACT 2601, Australia
²International Centre for Diarrheal Disease Research,Bangladesh, Mohakhali, Dhaka, Bangladesh

To estimate the prevalence and incidence of LTBI and risk factors among HCWs in Bangladeshi hospitals, we conducted a longitudinal study among HCWs in four chest disease hospitals. We included factors with a biologically plausible relationship with LTBI identified in prior studies or having an association (p=<0.20) in the bivariate analyses with TST positivity or QFT-GIT positivity in multivariable generalized linear models. The Kaplan-Meier method was used to estimate the cumulative LTBI incidence rate per 100 person-years.

In the study hospitals, of 758 HCWs invited, 732 (97%) consented to participate; 54% had a positive TST result and 47% had a positive QFT-GIT result. In multivariable models, HCWs working 11–20 years and >20 years in pulmonary TB wards had 1.8 (95% CI: 1.2–2.8) and 1.8 (95% CI: 1.01–3.2) times higher odds, respectively, of being TST-positive at baseline compared with those working ≤10 years. HCWs aged 41–50 years had 1.9 (95% CI: 1.1–3.3) times higher odds of TST positivity and 2.3 (95% CI: 1.2–4.2) times higher odds of QFT-GIT-positivity at baseline compared with those aged 18–30 years. LTBI incidence was 4.8/100 person-years by TST and 4.2/100 person-years by QFT-GIT. Females had 9.1 (95% CI: 1.6–53.2) times higher odds of TST conversion than males.

Prevalent TST positivity was associated with increased number of years working in pulmonary TB wards and increased age. The incidence of LTBI among HCWs suggests ongoing TB exposure in these facilities and an urgent need for improved TB IPC in chest disease hospitals in Bangladesh.

Biography: Md Saiful Islam is a social epidemiologist, recently completed his PhD in TB infection prevention and control.