Kozo Morimoto

The geographic diversity of nontuberculous mycobacteria isolated from pulmonary samples: an NTM-NET collaborative study

A significant knowledge gap exists concerning the geographical distribution of nontuberculous mycobacteria (NTM) isolation worldwide. To provide a snapshot of NTM species distribution, global partners in the NTM-Network European Trials Group (NET) framework (www.ntm-net.org), a branch of the Tuberculosis Network European Trials Group (TB-NET), provided identification results of the total number of patients in 2008 in whom NTM were isolated from pulmonary samples. From these data, we visualised the relative distribution of the different NTM found per continent and per country. We received species identification data for 20 182 patients, from 62 laboratories in 30 countries across six continents. 91 different NTM species were isolated. Mycobacterium avium complex (MAC) bacteria predominated in most countries, followed by M. gordonae and M. xenopi. Important differences in geographical distribution of MAC species as well as M. xenopi, M. kansasii and rapid-growing mycobacteria were observed. This snapshot demonstrates that the species distribution among NTM isolates from pulmonary specimens in the year 2008 differed by continent and differed by country within these continents. These differences in species distribution may partly determine the frequency and manifestations of pulmonary NTM disease in each geographical location. Species distribution among nontuberculous mycobacteria isolates from pulmonary specimens is geographically diverse http://ow.ly/npu6r

A steady increase in nontuberculous mycobacteriosis mortality and estimated prevalence in Japan.

RATIONALE Pulmonary disease caused by nontuberculous mycobacteria is generally reported to have a good prognosis. However, the actual mortality rate over time has not been reported in a large-scale survey. OBJECTIVES To determine the annual trend in mortality from nontuberculous mycobacteriosis, based on nearly four decades of patient data, and to estimate the prevalence of these cases in 2005. METHODS The annual mortality rate and regional distribution of nontuberculous mycobacteriosis-related deaths in Japan were obtained from Vital Statistics of Japan, which is published annually. The crude and age-adjusted mortality rates and associated regional differences were calculated from the Japanese census data. A 5-year follow-up study including 309 patients with pulmonary nontuberculous mycobacteriosis who visited and registered at our institute from 2004 to 2006 was conducted to determine the 5-year prognosis and the annual mortality rate. MEASUREMENTS AND MAIN RESULTS The crude mortality rates for both sexes have increased since 1970, and the mortality rate from pulmonary disease was greater in women after 2005. The age-adjusted rates of disease also showed a gradual increase until 2010 in women. Geographically, higher standardized mortality ratios were observed in middle and western Japan, particularly in the southern coastal regions along the Pacific Ocean. In a clinical follow-up study, the mortality rate was approximately 1-2% annually. The prevalence of pulmonary nontuberculous mycobacteriosis was estimated to be 6- to 10-fold higher than the annual incidence. CONCLUSIONS There was a constant and steady increase of nontuberculous mycobacteriosis-related mortality in Japan, and this mortality rate showed significant geographical variation. The prevalence of environmental mycobacterial disease in Japan is higher than reported in most other countries.

Epidemiology of pulmonary nontuberculous mycobacterial disease, Japan

To the Editor: Incidence of pulmonary nontuberculous mycobacterial disease (PNTMD) is reportedly increasing globally (1,2). Although such an increase is expected in Japan (3,4), the epidemiologic situation is unclear. The most recent survey, which used the 1997 American Thoracic Society diagnostic criteria, reported that the incidence rate for PNTMD in 2007 was 5.7 cases per 100,000 person-years (5). To update the data, we performed a nationwide hospital-based survey in Japan.

Poor adherence to management guidelines in nontuberculous mycobacterial pulmonary diseases

Nontuberculous mycobacterial pulmonary diseases (NTM-PD) are increasingly recognised as opportunistic infections of humans. Nodular/bronchiectatic disease and fibrocavitary disease are the most frequent manifestations [1]. Although guidelines have been published [1], there are few data on diagnostic and treatment practices outside of reference clinics. A recent survey in the USA suggested limited adherence to guidelines for diagnosis and treatment of NTM-PD [2]. Poor adherence to diagnosis and treatment guidelines for nontuberculous mycobacterial lung disease in EU and Japan http://ow.ly/EVYl306vVcN

A laboratory-based analysis of nontuberculous mycobacterial lung disease in Japan from 2012 to 2013

Rationale: Since 2010, mycobacterial examination results have been used widely to survey nontuberculous mycobacteria (NTM) lung disease. Objectives: To reveal the clinical and epidemiological status of NTM lung disease in Japan. Methods: All data on the isolation and identification of mycobacteria in 2012 and 2013 were obtained from three dominant commercial laboratories in Japan. Pulmonary NTM disease was defined on the basis of bacteriological diagnostic criteria issued by the American Thoracic Society/Infectious Diseases Society of America. The coverage population was estimated using the ratio between national tuberculosis registration data and laboratory results for each of the eight regions of Japan. Measurements and Main Results: A total of 113,313 mycobacterial specimens from 4,710 institutes were collected, and specimens from 26,059 patients tested positive for NTM cultures at least once. Among patients with positive cultures, 7,167 (27.5%) satisfied the American Thoracic Society/Infectious Diseases Society of America criteria for NTM lung disease, resulting in a 2‐year prevalence rate of 24.0 per 100,000. Mycobacterium avium complex (MAC) was the most commonly isolated species (93.3%), and 29.0% of the patients from whom MAC was isolated satisfied the criteria for NTM lung disease. Individuals older than 70 years of age accounted for the majority of cases, and 65.5% of cases involved females. After MAC, Mycobacterium kansasii and Mycobacterium abscessus exhibited the highest (43.6%) and second‐highest (37.1%) incidence per isolation, respectively. The prevalence of M. kansasii was highest in the Kinki region (P < 0.05), and M. abscessus had the greatest prevalence in the Kyushu‐Okinawa region (P < 0.005). The proportion of Mycobacterium intracellulare in MAC cases was higher in the southwestern part of Japan than in other regions. The period prevalence was highest in the southwestern part of Japan, and the standardized prevalence ratio was highest in central regions. Evaluations of clarithromycin susceptibility revealed a clear binomial distribution. Conclusions: This investigation is the first laboratory‐based study in which a large number of NTM isolated from clinical samples in Japan have been assessed. Although the calculated prevalence of NTM disease might be underestimated, the approach may prove useful for monitoring relative epidemiological data for NTM lung disease.

Evaluation of Humoral Immunity to Mycobacterium tuberculosis-Specific Antigens for Correlation with Clinical Status and Effective Vaccine Development

Although tuberculosis remains a major global health problem, Bacille Calmette-Guérin (BCG) is the only available vaccine. However, BCG has limited applications, and a more effective vaccine is needed. Cellular mediated immunity (CMI) is thought to be the most important immune response for protection against Mycobacterium tuberculosis (Mtb). However, the recent failure of a clinical trial for a booster BCG vaccine and increasing evidence of antibody-mediated immunity prompted us to evaluate humoral immunity to Mtb-specific antigens. Using Enzyme-Linked ImmunoSpot and Enzyme-Linked ImmunoSorbent Assays, we observed less correlation of both CMI and IgG titers with patient clinical status, including serum concentration of C reactive protein. However, IgA titers against Mtb were significantly correlated with clinical status, suggesting that specific IgA antibodies protect against Mtb proliferation. In addition, in some cases, IgA antibody titers were significantly associated with the serum concentration of total albumin, which supports the idea that humoral immunity can be influenced by the nutritional status. Based on these observations, we propose that the induction of humoral immunity should be included as an option in TB vaccine development strategies.

Pneumothorax associated with nontuberculous mycobacteria: A retrospective study of 69 patients.

AbstractThe incidence of nontuberculous mycobacterial pulmonary disease (NTMPD) is increasing worldwide. Secondary spontaneous pneumothorax occurs as a complication of underlying lung disease and is associated with higher morbidity, mortality, and recurrence than primary spontaneous pneumothorax. We here investigated the clinical features and long-term outcomes of pneumothorax associated with NTMPD.We conducted a retrospective study on consecutive adult patients with pneumothorax associated with NTMPD at Fukujuji Hospital and Keio University Hospital from January 1992 to December 2013. We reviewed the medical records of 69 such patients to obtain clinical characteristics, radiological findings, and long-term outcomes, including pneumothorax recurrence and mortality.The median age of the patients was 68 years; 34 patients were women. The median body mass index was 16.8 kg/m2. Underlying pulmonary diseases mainly included chronic obstructive pulmonary disease and pulmonary tuberculosis. On computed tomography, nodules and bronchiectasis were observed in 46 (98%) and 45 (96%) patients, respectively. Consolidation, pleural thickening, interlobular septal thickening, and cavities were most common, and observed in 40 (85%), 40 (85%), 37 (79%), and 36 (77%) patients, respectively. Regarding pneumothorax treatment outcomes, complete and incomplete lung expansion were observed in 49 patients (71%) and 15 patients (22%), respectively. The survival rate after pneumothorax was 48% at 5 years. By the end of the follow-up, 33 patients had died, and the median survival was 4.4 years with a median follow-up period of 1.7 years. The rate of absence of recurrence after the first pneumothorax was 59% at 3 years. By the end of the follow-up, 18 patients had experienced pneumothorax recurrence. Furthermore, 12/18 patients (66%) with recurrent pneumothorax died during the study period. Twenty-three patients (70%) died because of NTMPD progression. Low body mass index (BMI) was a negative prognostic factor for pneumothorax associated with NTMPD in multivariate analysis (HR 0.79, 95% CI 0.64−0.96; P = 0.018)Patients with pneumothorax associated with NTMPD have advanced disease, a high rate of pneumothorax recurrence, and poor prognosis, regardless of the pneumothorax treatment used. Further improvements in early diagnosis of NTMPD and appropriate management in both NTMPD and NTMPD-associated pneumothorax are needed.

Clinical and microbiological features of definite Mycobacterium gordonae pulmonary disease: the establishment of diagnostic criteria for low-virulence mycobacteria

BACKGROUND Although Mycobacterium gordonae isolation from respiratory samples is usually regarded as contamination, M. gordonae can cause definite pulmonary disease. The establishment of a standard diagnostic criteria of pulmonary disease that is caused by this low virulence mycobacterium is obviously necessary. METHODS We performed clinical research on over 200 cases in which M. gordonae was isolated over an 8-year period, focusing on the M. gordonae subtype. Sequence analysis of rpoB was performed to identify the genotypes. RESULTS A total of 287 respiratory samples (209 cases) were positive for M. gordonae. Twenty-seven cases (12.9%) had a positive culture more than twice and 11 of these cases (5.3%) had more than three positive cultures. Ultimately, three cases (1.4%) were newly diagnosed as M. gordonae pulmonary disease using our own diagnostic criteria. In all of the identified M. gordonae cases, the cultures tested positive with a Mycobacteria Growth Indicator Tube test at 24 days; however, in patients with definitive pulmonary disease, the cultures were positive at 9 days. A subtype analysis revealed that all of the definitive disease cases had subtype C. CONCLUSION The time taken to detect a positive culture and subtype of the isolates could be used as the diagnostic criteria for definite M. gordonae pulmonary disease.

The geographic diversity of nontuberculous mycobacteria isolated from pulmonary samples

A significant knowledge gap exists concerning the geographical distribution of nontuberculous mycobacteria (NTM) isolation worldwide. To provide a snapshot of NTM species distribution, global partners in the NTM-Network European Trials Group (NET) framework (www.ntm-net.org), a branch of the Tuberculosis Network European Trials Group (TB-NET), provided identification results of the total number of patients in 2008 in whom NTM were isolated from pulmonary samples. From these data, we visualised the relative distribution of the different NTM found per continent and per country. We received species identification data for 20 182 patients, from 62 laboratories in 30 countries across six continents. 91 different NTM species were isolated. Mycobacterium avium complex (MAC) bacteria predominated in most countries, followed by M. gordonae and M. xenopi. Important differences in geographical distribution of MAC species as well as M. xenopi, M. kansasii and rapid-growing mycobacteria were observed. This snapshot demonstrates that the species distribution among NTM isolates from pulmonary specimens in the year 2008 differed by continent and differed by country within these continents. These differences in species distribution may partly determine the frequency and manifestations of pulmonary NTM disease in each geographical location. Species distribution among nontuberculous mycobacteria isolates from pulmonary specimens is geographically diverse http://ow.ly/npu6r

Treatment outcome definitions in nontuberculous mycobacterial pulmonary disease: an NTM-NET consensus statement

Nontuberculous mycobacterial pulmonary diseases (NTM-PD) are increasingly recognised as opportunistic infections of humans. These chronic pulmonary infections have two main presentations. The first is a fibro-cavitary disease, that occurs in patients with pre-existing pulmonary diseases, such as chronic obstructive pulmonary disease, bronchiectasis, previous tuberculosis or other structural lung disease. The second presentation is a nodular-bronchiectatic disease of primarily the lingula and middle lobe that tends to affect a middle-aged and elderly female population [1]. Improving treatment outcome reporting in NTM disease: NTM-NET (@ntmnet) consensus statement on treatment outcome definitions http://ow.ly/c6IC30iwLM4