Association between Occupational and Radiological Factors and Nontuberculous Mycobacteria Lung Infection in Workers with Prior Dust Exposure.

Ji-Won Lee,Jun-Pyo Myong

doi:10.3390/ijerph16111966

Abstract

This retrospective cross-sectional study was conducted to identify the factors that promote the risk of nontuberculous mycobacteria (NTM) lung infection in subjects with prior occupational dust exposure. All consecutive patients with a history of occupational dust exposure whose expectorated sputum, bronchial wash, or bronchial lavage was subjected to acid-fast Bacilli culture in a tertiary hospital between 2011 and 2016 were identified. The patients who were infected with NTM were identified according to the bacteriological criteria of the American Thoracic Society (ATS) and The Infectious Diseases Society of America (IDSA) statement. Pneumoconiosis-associated radiological findings were graded according to the International Labor Organization guidelines. Of the 1392 patients with prior dust exposure, NTM was isolated from 82. Logistic regression analysis showed that risk factors for NTM lung infection were a history of pulmonary tuberculosis (adjusted odds ratio [aOR] = 1.82, 95% confidence intervals [CI] = 1.03–3.16). Moreover, the unadjusted odds ratios (ORs) were higher when both small-opacity profusion and the large-opacity grades increased. Even after adjustment, the ORs for the A, B, and C large-opacity grades were 2.32 (95% CI = 1.01–4.99), 2.68 (95% CI = 1.35–5.24), and 7.58 (95% CI = 3.02–17.95). Previous tuberculosis, bronchiectasis, and especially extensive small-opacity profusion, and high large-opacity grade associated significantly with NTM lung infection in dust-exposed workers.

Highlights

The nontuberculous mycobacteria (NTM) consist of all mycobacteria species except for Mycobacterium tuberculosis complex and Mycobacterium leprae
Compared with the patients without NTM lung infection, the patients with NTM lung infection were significantly more likely to be in their 60 s and 70 s, to have diabetes and hypertension, to have a history of pulmonary TB, and to have been a coal worker
This study showed that the risk factors for a diagnosis of NTM lung infection in patients with prior occupational dust exposure were previous TB, bronchiectasis, extensive small-opacity profusion, and higher large-opacity grades

Summary

Introduction

The nontuberculous mycobacteria (NTM) consist of all mycobacteria species except for Mycobacterium tuberculosis complex and Mycobacterium leprae. The most frequent target organ in NTM infections is the lung; more than 90% of NTM infections are in the lung [1,2]. Risk factors for NTM lung disease include pulmonary conditions that associate with structural lung changes. These conditions include chronic obstructive pulmonary disease (COPD), bronchiectasis, previous tuberculosis (TB), and pneumoconiosis [3,4]. The latter disease, pneumoconiosis, is a restrictive lung disease that is caused by working for prolonged periods in dusty conditions (e.g., mining). The Korean government considers NTM lung disease to be a complication of pneumoconiosis that deserves financial compensation

Methods

Results

Discussion

Conclusion