Who Has Mycobacterial Disease? A Cross Sectional Study in Agropastoral Communities in Tanzania.

Gibson Benard Kagaruki,Bernard James Ngowi,Julius Muhumuza,Esther Ngadaya,Sven Gudmund Hinderaker,Andrew Martin Kilale,Yakobo Leonard Lema,Sayoki Godfrey Mfinanga

doi:10.1371/journal.pone.0153711

Gibson Benard Kagaruki, Bernard James Ngowi + Show 6 more

Open Access

https://doi.org/10.1371/journal.pone.0153711

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Abstract

ObjectiveTo determine and describe clinical symptoms, demographic characteristics and environmental exposures as determinants of pulmonary mycobacterial diseases among patients examined for tuberculosis in agropastoral communities in Northern Tanzania.MethodsThis was a cross sectional study. Sputum samples were collected from patients attending three hospitals in Tanzania, and were investigated for pulmonary tuberculosis by microscopy between November 2010 and June 2012. The patients were interviewed about background information, and potential exposure to mycobacteria.ResultsWe examined 1,711 presumptive tuberculosis cases where 936 (54.2%) were males and 775 (45.3%) females. Of all the study participants, 277 (16%) were found to have sputum samples positive for mycobacteria; 228 (13%) were smear positive, 123 (7%) were culture positive and 74 (4%) were positive by both smear microscopy and culture. Of the 123 mycobacterial culture positive, 15 (12.2%) had non-tuberculous mycobacteria. Males were more likely than females to be positive for mycobacteria. Factors associated with mycobacterial disease were loss of appetite, age groups below 41 years, and being a male. Among HIV negative patients, loss of appetite, age below 20 years and being a male were associated with being mycobacterial positive. Among HIV positive patients, males and those patients with a persistently coughing family member were more likely to harbor mycobacteria.ConclusionThe findings in this study show that both M. tuberculosis and non-tuberculous mycobacterial strains were prevalent in the study community. Some risk factors were identified. Although the reported predictors may improve screening for mycobacterial diseases, their use requires some precaution.

Highlights

Mycobacteria are important acid-fast pathogens ranging from obligate intracellular parasites to environmental species [1]
The findings in this study show that both M. tuberculosis and non-tuberculous mycobacterial strains were prevalent in the study community
Of the sputum samples from 1711 study participants who were identified through symptoms and signs of pulmonary tuberculosis, 277 (16%) were confirmed to have mycobacteria by smear microscopy and culture

Summary

Introduction

Mycobacteria are important acid-fast pathogens ranging from obligate intracellular parasites to environmental species [1]. Diseases caused by mycobacteria and the role of the environment as a reservoir of infections to human is well documented [2,3]. Mycobacterial diseases cause considerable morbidity and mortality in patients with human immunodeficiency virus (HIV) infection [5,6]. There is evidence that HIV is a major risk factor for clinical tuberculosis as well as for illnesses associated with certain opportunistic non-tuberculosis mycobacteria, such as Mycobacterium avium-intracellulare [7]. In addition to altering the risk of diseases caused by mycobacteria, the clinical characteristics of tuberculosis in HIV-infected individuals produce a more disseminated infection [8] and are more likely to be sputum-negative than persons without HIV [9]

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