Clinical and microbiological characteristics of non-tuberculous mycobacteria diseases in Singapore with a focus on pulmonary disease, 2012-2016

BACKGROUND: Information on non-tuberculosis mycobacterial (NTM) diseases remains limited in Singapore and other Southeast Asian countries. This study aimed to delineate epidemiological and clinical features of pulmonary NTM disease. METHODS: A retrospective review was performed on all NTM isolates identified in Singapore General Hospital from 2012 to 2016 using the 2007 ATS/IDSA diagnostic criteria. RESULTS: A total of 2026 NTM isolates from 852 patients were identified. M. abscessus-chelonae group (1010, 49.9%) was the most commonly isolated and implicated in pulmonary NTM disease. Pulmonary cases (352, 76%) had the highest prevalence among patients diagnosed with NTM diseases (465/852, 54.6%) with no gender difference. Male patients were older (68.5 years, P = 0.014) with a higher incidence of chronic obstructive pulmonary disease (COPD) (23.6%, P < 0.001) and recurrent cough with phlegm production (51.6%, P = 0.035). In contrast, more female patients had bronchiectasis (50%, P < 0.001) and haemoptysis (37.6%, P = 0.042). Age and COPD were associated with multiple NTM species isolation per patient. CONCLUSIONS: M. abscessus-chelonae group was the commonest NTM species isolated in Singapore. Pulmonary NTM infection has the highest frequency with male and female patients associated with a higher incidence of COPD and bronchiectasis respectively. Age and COPD were associated with multiple NTM species isolation per patient.