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

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.

Nontuberculous Mycobacteria in Humans, Animals, and Water in Zambia: A Systematic Review

“…Of these 1/14 (7.14%) is focusing on humans and water (42), 1/14 (7.14%) was done in humans, cattle and Kafue Lechwe (5) and another one is a case report 1/14 (7.14%) (43), one is a pilot study 1/14 (7.14%) (44) and one a case control study 1/14 (7.14%) (44). The remaining 9/14 (64.29%) are all cross section study focusing on NTM in humans (20,(45)(46)(47)(48)(49)(50)(51)(52)(53). The study shows that the main specimens collected were sputum samples 10/14 studies (71.43%), one was a combination of sputum samples and brochoalveolar lavage, one was done on stored or archived isolates, one on a combination of stool samples, internal lavage and biopsy of the descending colon and lastly one was done on gastric lavage.…”

Non-Tuberculous Mycobacteria: Molecular and Physiological Bases of Virulence and Adaptation to Ecological Niches

“…Chronic bowel disease, also known as Crohn’s disease, has been proposed to be associated with MAP infection, also driven by the observation of patient improvement after antimycobacterial therapy, however, the presence of this species has seldom been detected in affected patients, so this topic possesses great controversy [ 267 , 268 ]. In addition to MAP infection, M. tuberculosis [ 269 ] and M. genavense [ 270 ] intestinal infections have been reported.…”

Non-tuberculous Mycobacterial Pseudo-outbreak of an Intestinal Culture Specimen Caused by a Water Tap in an Endoscopy Unit

“…Until infection control personnel of our hospital noted an unusual number of NTM positive specimen from the endoscopy unit, we overlooked water tap as a source of infection. Chongwe et al reported that NTM was isolated from 3% of colonic lavage sample before endoscopy ( 7 ). According to the annual isolation rate of intestinal fluid cultures for NTM in the present study ( Fig.…”