Clinical relevance of Mycobacterium malmoense isolation in the Netherlands

Abstract

Uncertainty exists about the clinical relevance of Mycobacterium malmoense isolation, especially in pulmonary samples. We therefore determined clinical relevance, treatment and outcome of M. malmoense isolation in the Netherlands.A retrospective medical file study was conducted for all patients in the Netherlands from whom Mycobacterium malmoense had been isolated between January 2002 and January 2006. Diagnostic criteria for nontuberculous mycobacterial (NTM) disease published by the American Thoracic Society (ATS) were used to determine clinical relevance. Treatment was compared with guidelines published by the British Thoracic Society.In total, 51 patients were found from whom M. malmoense was isolated. Of these, 40 (78%) patients had pulmonary isolates and 32 (80%) of them met the ATS diagnostic criteria. Cavitary disease was most common (n528; 88%). Patients with pulmonary disease were mostly males, with an average age of 56 yrs and pre-existing chronic obstructive pulmonary disease. Cervical lymphadenitis was the most common extrapulmonary disease type. Adherence to treatment guidelines was poor. A good clinical response to treatment was observed in 70% and 73% of patients treated for pulmonary and extrapulmonary disease, respectively.In conclusion, M. malmoense is a clinically highly relevant NTM in the Netherlands causing serious pulmonary morbidity. Adherence to treatment guidelines is not satisfactory.

Cervical abscess in an immunocompetent patient with Mycobacterium malmoense pulmonary disease

“…In two studies, involving 18 and 30 patients, a 13% mortality rate was noted [11,24]. However, in a BTS trial [8] with 106 patients and, more recently, in a study conducted by Andréjak et al [25] involving 46 individuals, a 5-year mortality rate of 34% and 47.2%, respectively, was observed.…”

“…Our extensive search for similar clinical presentations on PubMed found five cases of cervicofacial manifestations for this pathogen in adults and, unfortunately, little was documented about their clinical history (Table 2). Only one case, described by Hoefsloot et al [11], reported lymphadenitis concomitant to a pulmonary disease, but in a patient who received immunosupressive treatment after kidney transplantation.…”

“…Based on randomized trials, the British Thoracic Society (BTS) recommends a 12-to 24-month regimen with rifampicin (RMP) and ethambutol (EMB) for pulmonary disease [8]. Although less tolerated and despite the lack of evidence of benefit to date, several authors, including the ATS statement on NTM, commented on the addition of isoniazid, ciprofloxacin or clarithromycin to the regimen with RMP and EMB [11,21,22]. Although in vitro tests suggested an increased susceptibility for a combination with clarithromycin [23] and some resistance to EMB and RMP, there is no evidence that drug susceptibility testing contributes to the choice and response of any treatment regimen [1,8].…”

“…However, in a BTS trial [8] with 106 patients and, more recently, in a study conducted by Andréjak et al [25] involving 46 individuals, a 5-year mortality rate of 34% and 47.2%, respectively, was observed. In two of these studies, the outcomes have been negatively influenced by comorbidities, involvement of more than one lung zone, the length of delay between the diagnosis and start of treatment, and, less strongly, EMB resistance [8,11].…”

“…Most patients are male adults, with a mean age of 60 years, with underlying lung disease, especially chronic obstructive pulmonary disease (COPD), and present clinical symptoms and signs similar to those of pulmonary tuberculosis. The second group is formed by immunocompetent children, mostly younger than 5 years of age, with localized cervical lymphadenitis [1,6,8,[11][12][13]. Albeit rarely, other types of localized disease have been described, including skin, soft tissue infections and osteoarticular infections [14].…”