Epidemiology of and risk factors for extrapulmonary nontuberculous mycobacterial infections in Northeast Thailand

Irin Kham-Ngam; Ploenchan Chetchotisakd; Pimjai Ananta; Prajaub Chaimanee; Phuangphaka Sadee; Wipa Reechaipichitkul; Kiatichai Faksri

doi:10.7717/peerj.5479

Epidemiology of and risk factors for extrapulmonary nontuberculous mycobacterial infections in Northeast Thailand

PeerJ. 2018 Aug 16:6:e5479. doi: 10.7717/peerj.5479. eCollection 2018.

Authors

Irin Kham-Ngam^{1

2}, Ploenchan Chetchotisakd³, Pimjai Ananta^{1

4}, Prajaub Chaimanee⁴, Phuangphaka Sadee⁴, Wipa Reechaipichitkul³, Kiatichai Faksri^{1

2}

Affiliations

¹ Department of Microbiology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.
² Research and Diagnostic Center for Emerging Infectious Diseases, Khon Kaen University, Khon Kaen, Thailand.
³ Department of Medicine, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.
⁴ Clinical Laboratory Unit, Srinagarind Hospital, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.

Abstract

Background: Nontuberculous mycobacterial (NTM) infection is increasing worldwide. Current epidemiological data and knowledge of risk factors for this disease are limited. We investigated the trends in and risk of NTM infection in Northeast Thailand during 2012-2016.

Methods: Patient demographics, infection site(s), and underlying disease or conditions from 530 suspected cases of NTM infections were retrieved from medical records, reviewed and analyzed. A diagnosis of true NTM infection was accepted in 150 cases. Risk factor analyses were done for extrapulmonary NTM infections compared to pulmonary NTM infections and for Mycobacterium abscessus compared to members of the Mycobacterium avium complex (MAC). Trend analysis among NTM species causing NTM infections was performed.

Results: The most common species of NTMs causing extrapulmonary (n = 114) and pulmonary (n = 36) NTM infections in Northeast Thailand were M. abscessus (25.4% of extrapulmonary infected cases and 27.8% of pulmonary cases) followed by MAC (14.9% of extrapulmonary and 13.9% of pulmonary cases). Presence of anti-IFN-γ autoantibodies was the major risk factor for extrapulmonary (odds ratio (OR) = 20.75, 95%CI [2.70-159.24]) compared to pulmonary NTM infection. M. abscessus infection was less likely (OR = 0.17; 95%CI [0.04-0.80]) to be found in patients with HIV infection than was MAC infection. The prevalence of NTM infection, especially M. abscessus, in Northeast Thailand has recently increased. Extrapulmonary NTM and complicated NTM infections have increased in concordance with the recent trend of increasing frequency of anti-IFN-γ autoantibodies in the population.

Conclusions: M. abscessus was the commonest NTM pathogen followed by MAC. The prevalence of NTM infections and anti-IFN-γ are showing an upward trend. Autoimmune disease due to anti-IFN-γ is the major risk factor for extrapulmonary NTM infection in Northeast Thailand.

Keywords: Anti-IFN-γ; Extrapulmonary NTM infection; IFN-γ autoantibodies; Mycobacterium abscessus; Mycobacterium avium complex; Nontuberculous mycobacteria.

Grants and funding

This study was financially supported by General Supportive Grant, Khon Kaen University, Thailand 2018. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.