Spatial Epidemiologic Analysis and Risk Factors for Nontuberculous Mycobacteria Infections, Missouri, USA, 2008-2019

Mycobacterium shimoidei cavitary pneumonia: A rare case report, literature review

Mycobacterium shimoidei is a rare non-tuberculous mycobacterium (NTM) which causes pneumonia. Since its discovery in 1975, less than 50 cases have been published and this would be only the fourth case in the US. We present a case of Mycobacterium shimoidei in a 72-year-old male with symptoms of cough, dyspnea, and weight loss with cavitary lung lesion on imaging. Sputum cultures grew Mycobacterium shimoidei in two separate collections, and the patient was treated with oral azithromycin, ethambutol, and rifabutin empirically. Though due to medication side effects rifabutin was stopped and other antibiotics were attempted based on susceptibilities but he was unable to tolerate any of them. Thus, only a two-drug regimen including ethambutol and azithromycin was used, on which he improved clinically and cavitary lung lesions decreased in size. In addition, we did a literature review and compiled 41 previously published cases of Mycobacterium shimoidei.

Genomic Epidemiology of Extrapulmonary Nontuberculous Mycobacteria Isolates at Emerging Infections Program Sites-United States, 2019-2020

BACKGROUND

Nontuberculous mycobacteria (NTM) cause pulmonary and extrapulmonary infections. Although isolation of NTM from clinical specimens has increased nationally, few studies delineated the molecular characteristics of extrapulmonary NTM.

METHODS

Extrapulmonary isolates were collected by 4 Emerging Infections Program sites from October 2019 to March 2020 and underwent laboratory characterization, including matrix-assisted laser desorption ionization-time of flight mass spectrometry, Sanger DNA sequencing, and whole genome sequencing. Bioinformatics analyses were employed to identify species, sequence types (STs), antimicrobial resistance (AR), and virulence genes; isolates were further characterized by phylogenetic analyses.

RESULTS

Among 45 isolates, the predominant species were Mycobacterium avium (n = 20, 44%), Mycobacterium chelonae (n = 7, 16%), and Mycobacterium fortuitum (n = 6, 13%). The collection represented 31 STs across 10 species; the most common ST was ST11 (M. avium, n = 7). M. fortuitum and Mycobacterium abscessus isolates harbored multiple genes conferring resistance to aminoglycosides, β-lactams, and macrolides. No known AR mutations were detected in rpoB, 16S, or 23S rRNAs. Slow-growing NTM species harbored multiple virulence genes, including type VII secretion components, adhesion factors, and phospholipase C.

CONCLUSIONS

Continued active laboratory- and population-based surveillance will further inform the prevalence of NTM species and STs, monitor emerging clones, and allow AR characterization.

Relationship between age, sex, geography and incidence of nontuberculous mycobacteria in Denmark from 1991 to 2022

Objectives

We investigated age, sex and geographical differences in nontuberculous mycobacteria (NTM) incidence in Denmark.

Methods

A nationwide register-based study of all patients with NTM isolates in Denmark from 1991 to 2022 based on centralised microbiological data from the International Reference Laboratory of Mycobacteriology, Statens Serum Institut, Copenhagen, Denmark. A Poisson regression model was used to calculate incidence rates (IRs) and rate ratios (IRRs).

Results

4123 patients had NTM isolated for the first time. Their median age was 59 years (interquartile range 33-72), which increased over time. Males were younger than females. The proportion of females increased significantly over time. The type of NTM and patient age were closely associated. Pulmonary NTM isolation was increasingly common with higher age, while extrapulmonary NTM isolation was mainly seen in small children. Pulmonary NTM IRs were almost twice as high for females in 2008-2022 compared to 1991-2007 (IRR 1.9, 95% CI 1.7-2.1, p<0.001), with increases mainly seen in older age groups. The increase was less pronounced for males (IRR 1.3, 95% CI 1.1-1.4, p<0.001). There were considerable geographical differences, with age- and sex-adjusted NTM IRs being 10-40% higher in countryside, provincial and catchment municipalities than in the capital.

Conclusion

Age, sex and geography are essential determinants in NTM epidemiology. We found that rates of pulmonary NTM have been increasing, particularly in older females, while changes for males were less pronounced. Finally, we observed considerable geographical differences in NTM IRs in Denmark, with higher rates in less populated municipalities.

Multimodal machine learning-based model for differentiating nontuberculous mycobacteria from mycobacterium tuberculosis

Objective

To develop and evaluate the effectiveness of multimodal machine learning approach for the differentiation of NTM from MTB.

Methods

The clinical data and CT images of 175 patients were retrospectively obtained. We established clinical data-based model, radiomics-based model, and multimodal (clinical plus radiomics) model gradually using 5 machine learning algorithms (Logistic, XGBoost, AdaBoost, RandomForest, and LightGBM). Optimal algorithm in each model was selected after evaluating the differentiation performance both in training and validation sets. The model performance was further verified using external new MTB and NTM patient data. Performance was also compared with the existing approaches and model.

Results

The clinical data-based model contained age, gender, and IL-6, and the RandomForest algorithm achieved the optimal learning model. Two key radiomics features of CT images were identified and then used to establish the radiomics model, finding that model from Logistic algorithm was the optimal. The multimodal model contained age, IL-6, and the 2 radiomics features, and the optimal model was from LightGBM algorithm. The optimal multimodal model had the highest AUC value, accuracy, sensitivity, and negative predictive value compared with the optimal clinical or radiomics models, and its' favorable performance was also verified in the external test dataset (accuracy = 0.745, sensitivity = 0.900). Additionally, the performance of multimodal model was better than that of the radiologist, NGS detection, and existing machine learning model, with an increased accuracy of 26, 4, and 6%, respectively.

Conclusion

This is the first study to establish multimodal model to distinguish NTM from MTB and it performs well in differentiating them, which has the potential to aid clinical decision-making for experienced radiologists.

A practical guide to the diagnosis and management of suspected Non-tuberculous Mycobacterial Pulmonary Disease (NTM-PD) in the United Kingdom

Non-tuberculous Mycobacterial Pulmonary Disease (NTM-PD) is a chronic disease characterised by progressive inflammatory lung damage due to infection by non-tuberculous mycobacteria (NTM). Global prevalence of NTM-PD is generally low but is rising, likely due to a combination of increased surveillance, increasing multimorbidity and improved diagnostic techniques. Most disease is caused by Mycobacterium avium complex species. NTM-PD can be challenging to both diagnose and manage but given the risk of untreated disease and the challenges around drug treatments, it is vital that all healthcare professionals involved in primary care consider NTM-PD at the earliest opportunity. In particular, NTM-PD should be considered where there are respiratory symptoms in the setting of pre-existing chronic lung disease such as chronic obstructive pulmonary disease (COPD) and bronchiectasis. Early suspicion should lead to appropriate primary screening measures. This article discusses the relevance of NTM-PD today, risk factors for developing disease, pathways from clinical presentation to referral to specialist care, and discusses management and drug treatments. A flow diagram of a screening process is presented as a guideline for best practice from a United Kingdom perspective.

Mycobacterium heraklionense: An emerging cause of hand tenosynovitis

Misdiagnosis of Mycobacterium heraklionense tenosynovitis is common due to the challenging identification and perceived rarity of the disease. This can result in delayed therapy initiation and potentially irreversible consequences. In this report, we present an additional case of hand tenosynovitis, which highlights the diagnostic and management challenges of Mycobacterium heraklionense tenosynovitis and provides further evidence of its emergence as a cause of tenosynovitis. Additionally, we provide a comprehensive summary of published case reports that describe Mycobacterium heraklionense tenosynovitis.

Epidemiology of nontuberculous mycobacteria in the Finger Lakes region of New York

Clinical-epidemiologic data for all nontuberculous mycobacteria isolated in the 9 County Finger Lakes region of NY from 226 patients between 04/01/2018-03/31/2020 were retrospectively analyzed. Only 51% of patients meeting diagnostic criteria were treated, while 25% not meeting diagnostic criteria were also treated, indicating important knowledge gaps and research opportunities.

Nontuberculous mycobacterial pulmonary disease (NTM PD) incidence trends in the United States, 2010-2019

BACKGROUND

Nontuberculous mycobacteria (NTM) are ubiquitous environmental bacteria that cause chronic lung disease. Rates of NTM pulmonary disease (NTM PD) have increased over the last several decades, yet national estimates in the United States (US) have not been assessed since 2015.

METHODS

We used a nationally representative population of Medicare beneficiaries aged ≥ 65 years to assess rates of NTM PD in a high-risk population from 2010 to 2019. Poisson generalized linear models were used to assess the annual percent change in incidence in the overall population and among key demographic groups such as sex, geography, and race/ethnicity. We evaluated the relative prevalence of various comorbid conditions previously found to be associated with NTM PD.

RESULTS

We identified 59,724 cases of incident NTM PD from 2010 to 2019 from an annual mean population of 29,687,097 beneficiaries, with an average annual incidence of 20.1 per 100,000 population. NTM PD incidence was overall highest in the South and among women, Asian individuals, and persons aged ≥ 80 years relative to other studied demographic groups. The annual percent change in NTM PD incidence was highest in the Northeast, at 6.5%, and Midwest, at 5.9%, and among women, at 6.5%. Several comorbid conditions were highly associated with concurrent NTM diagnosis, including allergic bronchopulmonary aspergillosis, bronchiectasis, and cystic fibrosis.

CONCLUSIONS

Here we provide current estimates of NTM PD incidence and prevalence and describe increasing trends in the US from 2010 to 2019. Our study suggests a need for improved healthcare planning to handle an increased future caseload, as well as improved diagnostics and therapeutics to better detect and treat NTM PD in populations aged ≥ 65 years.

Climate change and resilience for antimicrobial stewardship and infection prevention

PURPOSE OF REVIEW

This review covers recent research regarding the challenges posed by climate change within the areas of antimicrobial stewardship and infection prevention, and ways to build resiliency in these fields.

RECENT FINDINGS

Infectious disease patterns are changing as microbes adapt to climate change and changing environmental factors. Capacity for testing and treating infectious diseases is challenged by newly emerging diseases, which exacerbate challenges to antimicrobial stewardship and infection prevention.Antimicrobial resistance is accelerated due to environmental factors including air pollution, plastic pollution, and chemicals used in food systems, which are all impacted by climate change.Climate change places infection prevention practices at risk in many ways including from major weather events, increased risk of epidemics, and societal disruptions causing conditions that can overwhelm health systems. Researchers are building resilience by advancing rapid diagnostics and disease modeling, and identifying highly reliable versus low efficiency interventions.

SUMMARY

Climate change and associated major weather and socioeconomic events will place significant strain on healthcare facilities. Work being done to advance rapid diagnostics, build supply chain resilience, improve predictive disease modeling and surveillance, and identify high reliability versus low yield interventions will help build resiliency in antimicrobial stewardship and infection prevention for escalating challenges due to climate change.

Spatial Heterogeneity of Nontuberculous Mycobacterial Pulmonary Disease in Shanghai: Insights from a Ten-Year Population-Based Study

OBJECTIVE

To investigate the spatial heterogeneity of nontuberculous mycobacterial pulmonary disease (NTM-PD) in Shanghai.

METHODS

A population-based retrospective study was conducted using presumptive pulmonary tuberculosis surveillance data of Shanghai between 2010 and 2019. The study described the spatial distribution of NTM-PD notification rates, employing hierarchical Bayesian mapping for high-risk areas and the Getis-Ord Gi* statistic to identify hot spots and explore associated factors.

RESULTS

Of 1652 NTM-PD cases, the most common species was Mycobacterium kansasii complex (MKC) (41.9%), followed by Mycobacterium avium complex (MAC) (27.1%) and Mycobacterium abscessus complex (MABC) (16.2%). MKC-PD patients were generally younger males with a higher incidence of pulmonary cavities, while MAC-PD patients were more often farmers or had a history of tuberculosis treatment. MKC-PD hot spots were primarily located in the areas alongside the Huangpu River, while MAC-PD hot spots were mainly in the western agricultural areas. Patients with MKC-PD and MAC-PD exhibited a higher risk of spatial clustering compared to those with MABC-PD.

CONCLUSIONS

Different types of NTM-PD exhibit distinct patterns of spatial clustering and are associated with various factors. These findings underscore the importance of environmental and host factors in the epidemic of NTM-PD.

Laboratory tests and analysis of drug resistance in non-tuberculous mycobacteria

Background

This study analyzed the laboratory diagnosis results and drug resistance of patients infected with non-tuberculous mycobacterium (NTM).

Methods

We collected information on patients with positive indicators of NTM infection at the Henan Provincial Chest Hospital from 2020 to 2022. Acid-fast smear, mycobacterium culture, QB-SPOT assay, GeneXpert MTB/RIF assay, immunoglobulin E test, tuberculosis antibody test, and microplate method for drug sensitivity test were analyzed using strain identification as the gold standard.

Results

The 242 cases of NTM infection were predominantly detected with slow-growing mycobacteria (a detection rate of 87.19%), among which Mycobacterium intracellulare (66.53%), Mycobacterium avium (15.70%), and Mycobacterium chelonei/abscessus complex (11.16%) ranked the top three in terms of the isolation rate. Males patients accounted for a higher proportion (58.26%) than females (41.74%), and the majority of them were over 60 years (50.83%). Among laboratory tests for patients with NTM infection, mycobacterium culture showed a highest detected rate (87.20%) among laboratory tests. The results of the drug sensitivity test demonstrated that the resistance rate of NTM was generally high. Moreover, the Mycobacterium avium complex with the highest isolation rate showed 100% resistant to doxycycline and minocycline, but exhibited relatively high sensitivity to moxifloxacin (a resistance rate of 7.89%) and rifabutin (a resistance rate of 13.16%). The Mycobacterium chelonei/abscessus complex was 100% resistant to doxycycline and relatively sensitive to cefoxitin (29.17%) and clarithromycin (37.50%).

Conclusion

The NTM species isolated by the Henan Provincial Chest Hospital is dominated by Mycobacterium intracellulare and the highest positive rate is detected by mycobacterium culture among laboratory tests. NTM infection generally exhibits a high rate of drug resistance. Accordingly, the accurate diagnosis of NTM diseases requires enhanced drug sensitivity testing to provide patients with targeted combination drug treatment.

Geographic Variation and Environmental Predictors of Nontuberculous Mycobacteria in Laboratory Surveillance, Virginia, USA, 2021-20231

Because epidemiologic and environmental risk factors for nontuberculous mycobacteria (NTM) have been reported only infrequently, little information exists about those factors. The state of Virginia, USA, requires certain ecologic features to be included in reports to the Virginia Department of Health, presenting a unique opportunity to study those variables. We analyzed laboratory reports of Mycobacterium avium complex (MAC) and M. abscessus infections in Virginia during 2021-2023. MAC/M. abscessus was isolated from 6.19/100,000 persons, and 2.37/100,000 persons had MAC/M. abscessus lung disease. M. abscessus accounted for 17.4% and MAC for 82.6% of cases. Saturated vapor pressure was associated with MAC/M. abscessus prevalence (prevalence ratio 1.414, 95% CI 1.011-1.980; p = 0.043). Self-supplied water use was a protective factor (incidence rate ratio 0.304, 95% CI 0.098-0.950; p = 0.041). Our findings suggest that a better understanding of geographic clustering and environmental water exposures could help develop future targeted prevention and control efforts.