The Incidence of Non-Tuberculous Mycobacteria in Infants in Kenya.

Grace Kaguthi,Suzanne Verver,Videlis Nduba,Wilfred Murithi

doi:10.1155/2019/1273235

Abstract

There is inadequate understanding of the epidemiology of Non-Tuberculous Mycobacteria (NTM) among infants in high tuberculosis burden countries. The objective of this study was to document the incidence and diversity of NTM disease or colonisation in sputum specimens from infants with presumptive TB, the risk factors, and clinical characteristics, in a high TB and HIV burden setting in Western Kenya. A cohort of 2900 newborns was followed for 1–2 years to assess TB incidence. TB investigations included collection of induced sputa and gastric aspirates for culture and speciation by HAIN®, Tuberculin Skin Testing (TST), HIV testing, and chest radiography. The American Thoracic Society Criteria (ATS) were applied to identify NTM disease. Among 927 (32% of 2900) with presumptive TB, 742 (80%) were investigated. NTM were isolated from 19/742 (2.6%) infants. M. fortuitum was most frequently speciated (32%). Total person-time was 3330 years. NTM incidence was 5.7/1,000 person-years, 95% CI (3.5, 8.7). Infants diagnosed with TB were more likely to have NTM isolation (odds ratio 11.5; 95% CI 3.25, 41.0). None of the infants with NTM isolated met the criteria for NTM disease. The incidence of NTM isolation was comparable to similar studies in Africa. NTM isolation did not meet ATS criteria for disease and could represent colonisation. TB disease appears to be structural lung disease predisposing to NTM colonisation.

Highlights

Non-Tuberculous Mycobacteria (NTM) are environmental saprophytes widely distributed in water and soil [1]
The discontinuation of universal BCG vaccination in these countries has seen an increase of NTM lymphadenitis in children, suggesting BCG was protecting against NTM in that setting [4]
There were no statistically significant differences between those who had NTM identified versus all other infants (Table 1)

Summary

Introduction

Non-Tuberculous Mycobacteria (NTM) are environmental saprophytes widely distributed in water and soil [1]. They are the genetic progenitors of M. The shared ancestry of NTM and MTBC is responsible for immune interference in BCG vaccination, via cross reactive immune responses [2]. This could be one of the reasons for low BCG efficacy where NTM are prevalent [2]. The discontinuation of universal BCG vaccination in these countries has seen an increase of NTM lymphadenitis in children, suggesting BCG was protecting against NTM in that setting [4]. NTM appear to be immune modulators influencing host interactions in BCG efficacy, TB burden, and NTM disease

Objectives

Methods

Results

Conclusion