Nontuberculous Mycobacterial Pulmonary Infection in Patients with Cystic Fibrosis

Epidemiological trends in nontuberculous mycobacterial infection among people with cystic fibrosis in Germany

OBJECTIVES

People with cystic fibrosis (pwCF) are at risk for infection with nontuberculous mycobacteria (NTM). The epidemiology and screening practice of NTM among pwCF in Germany are largely unknown and require investigation.

METHODS

We analyzed the data of the German Cystic Fibrosis Registry from 2016 to 2020 for NTM. The annual prevalence and incidence of any NTM, Mycobacterium abscessus complex (MABC), Mycobacterium avium complex (MAC), Mycobacterium gordonae, and other mycobacteria were determined and correlated to patient characteristics. Patients with incident MABC and MAC infection were compared.

RESULTS

The annual NTM prevalence and incidence remained stable between 7.53% and 8.76%, as well as 3.31% and 4.95%, respectively, among the approximately 6000 registry participants. MABC was the most common NTM, whereas only the prevalence of MAC increased slightly. In each year, only about one-third of all patients were screened for NTM. An association between NTM infections and Aspergillus fumigatus infection and/or allergic bronchopulmonary aspergillosis was observed. On average, patients with incident MAC infection were older than patients with MABC infection.

CONCLUSION

The NTM burden in pwCF in Germany remained unchanged between 2016 and 2020. MABC was the dominant species detected, whereas only MAC infections increased with time and patient age. The previously observed association of Aspergillus fumigatus and NTM was reaffirmed. Awareness of NTM needs to be improved.

Pulmonary infection with rapidly growing mycobacteria in a singer with achalasia: a case report

We report the case of a 37-year-old male patient with prolonged pneumonia and achalasia. Culture and molecular genetic typing identified Mycobacterium abscessus as causative agent. Treatment with clarithromycin and minocycline over 8 months gradually resolved the infection. Rapidly growing, non-obligate pathogenic mycobacteria are widespread in the environment. Several cases of pulmonary infections with these mycobacteria in patients with achalasia have been reported, suggesting a causative association. This is the first report of a case with isolation of M. abscessus in this context.

Is limited computed tomography the future for imaging the lungs of children with cystic fibrosis?

Perspective on the paper by Jiménez et al (see page 388)

Mycobacterium chelonae in a CF patient with anaplastic large cell lymphoma

A 13-year-old patient with cystic fibrosis was diagnosed with anaplastic large cell lymphoma. At the same time colonization with Mycobacterium chelonae was detected in sputum cultures. Despite massive immunosuppression, the patient did not show evidence of mycobacterial invasive disease. Colonisation persisted for 18 months after discontinuation of chemotherapy and was not detected in the 6 years thereafter. This case highlights the dilemma of differentiating between colonisation and infection if mycobacteria are found in CF sputum samples.

Computed Tomography in the Evaluation of Cystic Fibrosis Lung Disease

The first report of computed tomography (CT) scanning to monitor cystic fibrosis (CF)-related lung disease was published in 1986. Further publications followed, but in general there was little interest in this technique until recently. Two factors in particular have led to this increased interest. First is an increasing realization that pulmonary function tests, long the mainstay of CF evaluation, often underestimate the presence and severity of mild and moderate lung disease. Second is the need for more sensitive outcome measures to assess new therapies. This had led to new interest and a series of important publications. The goal of this article is to present the current status of CT scanning in CF.

[Nontuberculous mycobacteria in patients with cystic fibrosis]

OBJECTIVE

Patients with cystic fibrosis are at great risk of infection by nontuberculous mycobacteria from the environment because of certain predisposing factors such as bronchiectasis, malnutrition, and diabetes. The aim of this study was to analyze the mycobacterial content of sputum smears and cultures from adult patients with cystic fibrosis attended at a specialized unit for adults from March 1997 through December 2001.

PATIENTS AND METHODS

Sputum samples were collected prospectively according to a protocol applied at each visit, and during most exacerbations staining and culture for mycobacteria were ordered in addition to the usual cultures for bacteria and fungi. A tuberculin test was performed at the end of the study.

RESULTS

Twenty-eight patients (16 men) with cystic fibrosis were enrolled. The mean (SD) age was 25.3 (6.7) years. A total of 251 samples were cultured (range in number of samples per patient, 1-31). The mean period of follow up was 40.3 (22.1) months. The sputum smear was positive in 29 cases (4 patients); the culture was positive in 7 patients. More than 3 samples were positive in only 4 patients. Mycobacterium abscessus was isolated in 3 cases, Mycobacterium avium complex in 2 and Mycobacterium simiae in 1 and other an unidentified rapid growth Mycobacterium species. The Mantoux test was positive in 5 patients. Two of the 4 patients in whose samples mycobacteria were isolated repeatedly required treatment.

CONCLUSIONS

The prevalence of nontuberculous mycobacterial infection is high in patients with cystic fibrosis. Staining and culture for mycobacteria should be carried out regularly and whenever exacerbation of pulmonary symptoms cannot be attributed to bacteria usually found in such patients. Patients with recurrent isolations of mycobacteria should be monitored closely.