Nontuberculous mycobacteria infection in people with cystic fibrosis attending cystic fibrosis treatment clinics in Australia

Abstract

Objectives: Chronic nontuberculous mycobacterial (NTM) infections have rapidly emerged in people with CF and pose a significant threat to their survival. This prospective study aims to determine the prevalence and incidence of NTM in Australia as part of the ongoing National NTM in CF study. Methods: A risk based cohort study is underway in 19 CF centres in Australia. Recruits are consenting adult or paediatric individuals with CF who produce a respiratory sample as part of a routine clinical visit (sputum, bronchoalveolar lavage or induced sputum). Samples are collected at baseline, six and 12 months and sent for mycobacterial culture. Nationally 508 adult and 304 paediatric recruits have provided up to 3 sputum samples for mycobacterial culture (September 2016 - December 2018). Results: Preliminary findings indicate that NTM infection is higher in paediatric recruits (9.9%) compared to adult recruits (6.5%) nationally, Mycobacterium abscessus group (MABS) infections (51.0%) are the predominant NTM infection in paediatric patients followed by M. avium complex (MAC) infections (39.2%). In contrast, MAC species are the most commonly isolated NTM species (49.0%) in adults, followed by MABS (36.7%). Preliminary data indicates that this pattern of infection varies from state to state within Australia. In the National cohort, NTM positive recruits are significantly younger than the NTM-negative recruits (p < 0.05). Recruits infected with MABS have a significant reduction in mean FEV1% pred (62.3% ± 17.8 SD) when compared to age matched NTM negative recruits (79.3% ± 20.0 SD). Conclusion: Younger people with CF are more likely to acquire MABS. Participants with MABS infections have reduced lung function compared to age matched peers without NTM infections or those infected by slow growing mycobacterial species. It is not known if poor lung function is a marker for acquisition of MABS or a result of MABS infection.L20019762102019-11-11 <br />