A first insight into high prevalence of undiagnosed smear-negative pulmonary tuberculosis in Northern Ethiopian prisons: implications for greater investment and quality control.

Fantahun Biadglegne,Ulrich Sack,Arne C Rodloff,Franklin D Lowy

doi:10.1371/journal.pone.0106869

Fantahun Biadglegne, Ulrich Sack + Show 2 more

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https://doi.org/10.1371/journal.pone.0106869

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Abstract

BackgroundTuberculosis (TB) transmission in prisons poses significant risks to inmates as well as the general population. Currently, there are no data on smear-negative pulmonary TB cases in prisons and by extension no data on the impact such cases have on TB incidence. This study was designed to obtain initial data on the prevalence of smear-negative cases of TB in prisons as well as preliminary risk factor analysis for such TB cases.MethodsThis cross-sectional survey was conducted in November 2013 at eight main prisons located in the state of Amhara, Ethiopia. Interviews using a structured and pretested questionnaire were done first to identify symptomatic prisoners. Three consecutive sputum samples were collected and examined using acid fast bacilli (AFB) microscopy at the point of care. All smear-negative sputum samples were taken for culture and Xpert testing. Descriptive and multivariate analysis was done using SPSS version 16.ResultsOverall the prevalence of smear-negative pulmonary TB cases in the study prisons was 8% (16/200). Using multivariate analysis, a contact history to TB patients in prison, educational level, cough and night sweating were found to be predictors of TB positivity among smear-negative pulmonary TB cases (p≤ 0.05).ConclusionsIn the studied prisons, high prevalence of undiagnosed TB cases using AFB microscopy was documented, which is an important public health concern that urgently needs to be addressed. Furthermore, patients with night sweating, non-productive cough, a contact history with TB patients and who are illiterate merit special attention, larger studies are warranted in the future to assess the associations more precisely. Further studies are also needed to examine TB transmission dynamics by patients with smear-negative pulmonary TB in a prison setting.

Highlights

Tuberculosis (TB) is one of the leading causes of death in the world
Sub-Saharan Africa, including Ethiopia, is an area with high prevalence of TB infection and in 2013; a WHO report showed that Ethiopia ranks seventh among the world’s 22 countries with a high tuberculosis burden [2]
Studies in Malawi, Ivory Coast and Botswana showed higher prevalence of smear-positive pulmonary TB in prisons compared to in the civilian population [7,8,9]. This increased incidence has been associated with the human immunodeficiency virus (HIV) epidemic [10]

Summary

Introduction

Tuberculosis (TB) is one of the leading causes of death in the world. Globally, around 8.8 million people develop TB and 1.45 million people die every year due to TB, of which 0.35 million deaths are associated with HIV-TB co-infection [1]. Sub-Saharan Africa, including Ethiopia, is an area with high prevalence of TB infection and in 2013; a WHO report showed that Ethiopia ranks seventh among the world’s 22 countries with a high tuberculosis burden [2]. Studies in Malawi, Ivory Coast and Botswana showed higher prevalence of smear-positive pulmonary TB in prisons compared to in the civilian population [7,8,9]. This increased incidence has been associated with the human immunodeficiency virus (HIV) epidemic [10]. This study was designed to obtain initial data on the prevalence of smear-negative cases of TB in prisons as well as preliminary risk factor analysis for such TB cases

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