Diagnostic yield of nontuberculous mycobacteria in patients booked for endoscopy at the University Teaching Hospital, Lusaka

Gershom Chongwe,Paul Kelly,Charles Michelo

doi:10.1186/s13104-016-2329-3

Abstract

BackgroundThe intestinal carriage of nontuberculous mycobacteria (NTM) is associated with disease, especially in severely immunocompromised individuals. These organisms, although often considered contaminants, have been known to cause various types of illnesses. We aimed to determine the prevalence of and associated factors for NTM among patients booked for colonoscopy at the University Teaching Hospital (UTH) in Lusaka.MethodsWe randomly recruited 97 patients attending routine endoscopy procedures between November 2012 and October 2013 and after consent, administered a structured questionnaire. We collected stool and intestinal lavage samples, as well as biopsy samples from the descending colon and the caecal area during the endoscopy procedure. Samples were cultured using the mycobacteria growth indicator tube (MGIT) method followed by the GenoType Mycobacterium CM/AS assay for identification of NTM. Results were expressed as means and standard deviations; proportions were expressed as percentages with corresponding 95% confidence intervals. We used Fisher’s exact Chi square test for cross-tabulations where appropriate. All statistical tests were two-sided, with a significance level set at p < 0.05.ResultsOut of the 97 patients, 45 (46.4%) were female and 52 (53.6%) were males with mean ages 49.1 (±16.7, range 24–85) and 44.4 (±15.0, range 18–80) years respectively. The prevalence of NTM was 7.2% (95% CI 1.9–12.4), while that of Mycobacterium tuberculosis (MTB) was 6.2% (95% CI 2.3–13.0). Carriage of NTM was not significantly associated with age, sex or presenting symptoms such as diarrhoea, abdominal pain, weight loss as well as HIV status. There were no identifiable predictors of NTM carriage.ConclusionThe results have shown that NTM and MTB are present in the intestines of the patients booked for colonoscopy at the University Teaching Hospital in Lusaka, but their presence is not related to presenting symptoms. Given that this may be an indicator of a bigger burden of NTM in this population, there is a need to explore this burden and the contribution it could have on abdominal disease in general as well as examine potential factors that might be important predictors.

Highlights

The intestinal carriage of nontuberculous mycobacteria (NTM) is associated with disease, especially in severely immunocompromised individuals
Mycobacterium species different from those belonging to the Mycobacterium tuberculosis complex (MTB) and M. leprae
In this study, we found evidence of NTM among patients booked for colonoscopy and flexible sigmoidoscopy at University Teaching Hospital (UTH)

Summary

Introduction

The intestinal carriage of nontuberculous mycobacteria (NTM) is associated with disease, especially in severely immunocompromised individuals. These organisms, often considered contaminants, have been known to cause various types of illnesses. The intestinal carriage of nontuberculous mycobacteria (NTM) is associated with disease in both immunocompetent as well as immunocompromised individuals [1]. Nontuberculous mycobacteria (NTM) are a group of Mycobacterium species different from those belonging to the Mycobacterium tuberculosis complex (MTB) and M. leprae. Some of the conditions predisposing to systemic, respiratory and abdominal NTM disease include HIV, emphysema, pneumoconiosis, cystic fibrosis, previous gastrectomy, continuous ambulatory dialysis and chronic alcoholism [7,8,9]. Both M. tuberculosis and NTM can cause abdominal pain, ascites, chronic diarrhoea and other clinical manifestations [10]

Objectives

Methods

Results

Discussion

Conclusion