Prevalence of latent tuberculosis infection and feasibility of TB preventive therapy among Thai prisoners: a cross-sectional study

Sivaporn Gatechompol,Stephen J Kerr,Sasiwimol Ubolyam,Ruamthip Supanan,Kamon Kawkitinarong,Jiratchaya Sophonphan,Anchalee Avihingsanon,Weerakit Harnpariphan,Gompol Suwanpimolkul

doi:10.1186/s12889-021-11271-0

Abstract

BackgroundPrisons are considered as major reservoirs for tuberculosis. Preventive therapy for latent TB infection (LTBI) is an adjunctive strategy to control TB. However, LTBI data in Thai prisoners is limited. This study assessed the prevalence of LTBI and feasibility of isoniazid preventive therapy (IPT).MethodsA cross-sectional study was conducted among prisoners in Klong Prem Central Prison, Bangkok. Participants were screened for active TB by questionnaire and chest X-ray. LTBI was evaluated by Tuberculin skin test (TST) and QuantiFERON-TB Gold Plus (QFTP) among subgroup. Participants with positive TST or QFTP were considered to have LTBI. Participants with LTBI were offered IPT.ResultsFrom August 2018–November 2019, 1002 participants were analyzed. All participants were male with a median age of 38 (IQR 32–50) years. LTBI identified by either TST/QFTP was present in 466 (46.5%) participants. TST was positive in 359 (36%) participants. In the subgroup of 294 participants who had both TST and QFTP results, 181/294 (61.6%) tested positive by QFTP. Agreement between TST and QFTP was 55.1% (Kappa = 0.17). The risk factors associated with LTBI were previous incarceration (aOR 1.53, 95%CI, 1.16–2.01, p = 0.002), history of prior active TB (aOR 3.02, 95%CI, 1.74–5.24, p < 0.001) and duration of incarceration ≥10 years (aOR 1.86, 95%CI, 1.24–2.79, p = 0.003). Majority of LTBI participants (82%) agreed to take IPT. Three hundred and 56 (93%) participants completed treatment whereas 27 (7%) participants discontinued IPT due to the side effects of INH.ConclusionThis is the first study to evaluate the prevalence of LTBI and feasibility of IPT among Thai prisoners. LTBI prevalence in male prisoners in Thailand is high. LTBI screening and treatment should be implemented together with other preventive components.

Highlights

Prisons are considered as major reservoirs for tuberculosis
Many prisoners are from populations at high risk for TB infection and active TB disease, such as alcohol or drug users and people living with human immunodeficiency virus (HIV) [6]
Participant characteristics Among the total of 6194 inmates in this prison, 3700 inmates who have more than 50 years sentence were located in the highest security zone

Summary

Introduction

Preventive therapy for latent TB infection (LTBI) is an adjunctive strategy to control TB. One challenge is the high TB incidence among high risk populations, including prisoners. TB incidence is 5 to 70 times greater in prisons than in general population [3]. Prisons act as an institutional TB amplifier, facilitating transmission to the general population through released inmates, especially in low-middle income countries [4]. Many prisoners are from populations at high risk for TB infection and active TB disease, such as alcohol or drug users and people living with human immunodeficiency virus (HIV) [6]. Structural and institutional factors contributing to transmission of TB in prisons include poor ventilation, overcrowding, delayed diagnosis and inadequate treatment

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Conclusion