Prevalence, risk factors and prognosis of nontuberculous mycobacterial infection among people with bronchiectasis: a population survey

Abstract

The incidence of nontuberculous mycobacteria (NTM) infection among people with bronchiectasis varies between different geographical areas and accordingly between different series [1, 2]. Studies are largely based on bronchiectasis referral centres, which routinely screen for NTM in respiratory secretions. Therefore, the reported estimates of NTM prevalence in bronchiectasis may be exaggerated. Studies from bronchiectasis centres show conflicting results regarding risk factors for NTM: older age was found to increase risk in some but not other centres [1-4]. Due to the small numbers of patients in these studies, it is usually not possible to determine the effect of NTM infection on prognosis. Utilising the population registry of Israel's largest health maintenance organisation [5], we aimed to determine the incidence, risk factors and prognosis of NTM infection among patients with bronchiectasis. The database was searched for adults with bronchiectasis on January 1, 2010, excluding cystic fibrosis and idiopathic pulmonary fibrosis. We searched for laboratory codes indicating NTM between January 2010 and December 2016. We defined three categories of NTM. 1) "Growth": a single culture positive for any NTM. 2) "Colonisation": at least two cultures positive for the same NTM species. 3) "Treated": either of the above categories, treated with three or more antimycobacterial drugs. Medication use was determined from pharmacy reports. Socioeconomic status (SES) was based on the SES score of the clinic neighbourhood as defined by the Israeli Central Bureau of Statistics [6]. Mortality and hospitalisations during follow-up (2010-2016) were compared between patients with and without NTM infection. Multivariate logistic regression was used to identify the NTM risk factors. The Cox time dependent model was used to identify prognostic factors that influence hospitalisation and mortality. On January 1, 2010, the database included 2 710 432 adults. Of these, 6347 had a diagnosis of bronchiectasis (234 in 100 000). 6274 patients were without NTM infection prior to January 1. Of them, only 1871 (30%) patients had mycobacterial cultures available. In the general population (without bronchiectasis), 1476 (0.055%) people had NTM from respiratory specimens during follow up. Among people with bronchiectasis (n=6274), 105 (1.7%) grew NTM during follow-up. Only 30 (0.48%) cases had two or more cultures of the same NTM species, representing colonisation. Treatment with a combination of three or more antimycobacterial drugs was found in 12 (0.19%) patients. The incidence of NTM growth among all patients with bronchiectasis (n=6274) was estimated in four strata of age: 18-39, 40-59, 60-79 and ⩾80 years. The corresponding incidence of NTM growth were 1.1%, 2.2%, 1.9% and 0.9%, respectively (p=0.030). 50% of patients were 60-80 years old with a similar age distribution between patients with and without available mycobacterial cultures. Overall, 43% of patients with bronchiectasis in our study had emigrated from areas where tuberculosis is comm...

Non-tuberculous mycobacterial lung disease in patients with bronchiectasis: perceived risk, severity and guideline adherence in a European physician survey

“…4 NTM isolation prevalence in patients with bronchiectasis ranges from 2% to 63%. [5][6][7][8] Open access European guidelines for the management of bronchiectasis recommend regular testing for NTM isolation, particularly where NTM are suspected as a cause of bronchiectasis. Testing should be carried out prior to initiation of long-term macrolide monotherapy to prevent exacerbations, in order to avoid development of macrolideresistant NTM.…”

Characterization of non-tuberculous mycobacterial pulmonary disease in Nanjing district of China

“…As NTM are environmental bacteria, a substantial number of patients have no known risk factors. However, some underlying host risk factors for NTM infection have been extensively studied, like allogeneic hematopoietic cell transplantation (AHCT) [35–37]. Remarkably, the patients with predisposed lung disease are more susceptible to NTM infection [30, 38].…”

Recommendations for travelling with bronchiectasis: a joint ELF/EMBARC/ERN-Lung collaboration

“…People with bronchiectasis are at risk of acquiring infections with NTM [17–21] with prevalence rates that range from 5% [17] to 50% in different series [19]. Series from the United States, especially Hawaii, repeatedly report an elevated prevalence of NTM pulmonary disease.…”

“…It is therefore not recommended for people with bronchiectasis to avoid travelling to places with a high prevalence of NTM. However, this recommendation may be individualised for people with severe bronchiectasis and features of a high risk of NTM infection [17].…”