Clinical relevance of non-tuberculous mycobacteria isolated in the Nijmegen-Arnhem region, The Netherlands

Abstract

Background: The frequency of clinical isolation of nontuberculous mycobacteria (NTM) in the Netherlands is increasing, but its clinical relevance is often uncertain. Objective: To assess the frequency and clinical relevance of isolation of NTM in four associated hospitals in a single region in the Netherlands. Methods: Medical files of all patients from whom NTM were isolated between January 1999 and January 2005 were reviewed retrospectively. Diagnostic criteria for nontuberculous mycobacterial disease published by the American Thoracic Society (ATS) were used to determine clinical relevance. Results: 232 patients were found, from whom NTM were isolated from the respiratory tract in 91% of cases. Patients were mostly white men, with an average age of 60 years and pre-existing pulmonary disease. Fifty-three of 212 patients (25%) with pulmonary isolates met the ATS diagnostic criteria for pulmonary NTM disease; this percentage differed by species. Most patients were treated with rifampicin, ethambutol and clarithromycin. Treatment outcome for pulmonary NTM disease was suboptimal but differed by species: overall, improvement was seen in 67% of treated patients, but in only 50% of those with pulmonary M avium disease. Lymphadenitis was the most common extrapulmonary disease type. Conclusions: Twenty-five per cent of all patients with pulmonary NTM isolates met the ATS criteria. Clinical relevance differs by species. NTM isolation increases over time. Species distribution differs from that of neighbouring countries and the M avium complex isolates have traits different from those reported in the USA. Adherence to diagnostic and treatment guidelines can be improved.The clinical isolation of non-tuberculous mycobacteria (NTM) increases in many countries where the incidence of tuberculosis is decreasing, with marked geographical differences in the species encountered.

Nontuberculous Mycobacteria in Respiratory Tract Infections, Eastern Asia

“…This finding contrasts with studies of NTM in other parts of the world ( 3 ). In a surveillance study from the Netherlands for instance, RGM caused only 3% of all pulmonary NTM infections ( 2 ). In the United States, this percentage is ≈5% ( 36 ).…”

Geographical distribution and clinical relevance of non-tuberculous mycobacteria in Croatia

“…We found interesting regional differences. Even though the majority of all NTM isolates came from continental Croatia, most of those were species generally considered of low virulence [1,13]. In contrast, clinically relevant NTM isolates were significantly more often found in the coastal region of Croatia.…”

“…However, the number of cases of M. gordonae disease is likely overestimated, since it is known to rarely cause true disease [1,13]. Discarding all of the M. gordonae cases, the annual incidence would be 0.38/100,000.…”

“…kansasii were more strongly associated with disease than M. avium and M. intracellulare [13], applying the full ATS diagnostic criteria [1]. The background of such apparent regional differences remains unknown.…”

Pulmonary Nontuberculous Mycobacterial Infections in the State of Para, an Endemic Region for Tuberculosis in North of Brazil

“…Therefore, guidelines and criteria for diagnosis of NTM pulmonary disease have been published (American Thoracic Society, 1997;British Thoracic Society, 2000) followed by the publication of a recent update of more lenient criteria . Even so, these recommendations do not seem to be satisfactory as most patients with pulmonary disease due to NTM do not match these criteria (Marras et al, 2007;van Ingen et al, 2009). Also, in endemic countries for tuberculosis (TB), the pulmonary disease form is caused also by infection with organisms of the MTBC, presenting similar clinical symptoms.…”