Mycobacterium Avium Complex Infection Research Articles

Clinical efficacy and safety of endobronchial one-way valves for the treatment of bronchopleural fistula

Objective: To investigate the efficacy and safety of interventional endobronchial one-way valves (EBV) for the treatment of peripheral bronchopleural fistula (BPF). Methods: A total of 33 patients with peripheral BPF who underwent EBV implantation in Endoscopy Center of Shanghai Pulmonary Hospital from August 2017 to December 2021 were selected as the research objects. All the patients were diagnosed with peripheral BPF before the implantation surgery. The detailed medical records of the patients were collected, and the etiology, lesion location, treatment method and operation process, treatment efficacy and postoperative complications were analyzed to evaluate the efficacy and safety of EBV implantation. Results: Of the 33 patients in our study, 26 were male and 7 were female. The median age was 54.7 (28-86) years. There were 18 cases of BPF after thoracic surgery (54.5%), 6 cases of chronic obstructive pulmonary disease complicated with spontaneous pneumothorax (18.2%), and 12 cases of pulmonary tuberculosis and non-tuberculous mycobacterial infection with spontaneous pneumothorax (36.4%). A total of 63 valves were inserted in the 33 cases, and a maximum of valves and at least one were inserted in a single case. The lesions were located in the right lower lobe in 16 cases (48.5%) and the left upper lobe in 12 cases (36.4%). Of the 33 patients undergoing EBV placement, 22 (66.7%) were successful, with chest drainage tube indwelling duration of (88.5±36.6) days and (29.6±11.4) days, respectively, before and after EBV treatment. The time from EBV placement to successful withdrawal of EBV was (102.2±31.3) days. During a postoperative follow-up of 6 months after EBV treatment, the main complications were 29 cases with attachment of secretions to the EBV (90.6%) and 13 cases (40.6%) with mild granulation proliferation. In addition, there were five patients with moderate to severe granulation proliferation (15.6%), one with valve displacement or shedding (3.1%), and one with bleeding (3.1%). Conclusions: In this study, the success rate of EBV placement and occlusion was 66.7%. Transbronchoscopic EBV placement in the treatment of peripheral BPF is a effective treatment with relatively minor complications.

Modulating macrophage function to reinforce host innate resistance against Mycobacterium avium complex infection.

Mycobacterium avium complex (MAC) is the main causative agent of infectious diseases in humans among nontuberculous mycobacteria (NTM) that are ubiquitous organisms found in environmental media such as soil as well as in domestic and natural waters. MAC is a primary causative agent of NTM-lung disease that threaten immunocompromised or structural lung disease patients. The incidence and the prevalence of M. tuberculosis infection have been reduced, while MAC infections and mortality rates have increased, making it a cause of global health concern. The emergence of drug resistance and the side effects of long-term drug use have led to a poor outcome of treatment regimens against MAC infections. Therefore, the development of host-directed therapy (HDT) has recently gained interest, aiming to accelerate mycobacterial clearance and reversing lung damage by employing the immune system using a novel adjuvant strategy to improve the clinical outcome of MAC infection. Therefore, in this review, we discuss the innate immune responses that contribute to MAC infection focusing on macrophages, chief innate immune cells, and host susceptibility factors in patients. We also discuss potential HDTs that can act on the signaling pathway of macrophages, thereby contributing to antimycobacterial activity as a part of the innate immune response during MAC infection. Furthermore, this review provides new insights into MAC infection control that modulates and enhances macrophage function, promoting host antimicrobial activity in response to potential HDTs and thus presenting a deeper understanding of the interactions between macrophages and MACs during infection.

Pulmonary Non-tuberculous Mycobacterial Infections in Category II Failures from National Tuberculosis Programme

Pulmonary infections due to non-tuberculous mycobacteria (NTM) are increasingly being reported. These can mimic drug-resitant tubercuolosis. A diagnosis of NTM infections needs a high degree of clinical suspicion and repeated isolation of the organism on culture. NTM infections occur commonly in immunocompromised individuals and in people with lung abnormalities. Currently there are no guidelines on drug combinations and the duration of treatment is not adequately defined. Two cases of pulmonary infection with NTM in immune-competent individuals are described in the present report. Although the bacteriological, radiological and clinical response to treatment was good; early discontinuation of treatment resulted in recurrence and change in drug susceptibility pattern, suggesting the need for prolonged treatment for achieving cure.

Circulating mitochondrial cell-free DNA dynamics in patients with mycobacterial pulmonary infections: Potential for a novel biomarker of disease.

Human mitochondrial cell-free DNA (Mt-cfDNA) may serve as a useful biomarker for infectious processes. We investigated Mt-cfDNA dynamics in patients with pulmonary mycobacterial infections to determine if this novel biomarker could be used to differentiate disease states and severity. Patients with pulmonary tuberculosis (PTB), latent tuberculosis infection (LTBI), and nontuberculous mycobacterial-lung disease (NTM-LD) were enrolled at a tertiary care hospital in Taiwan between June 2018 and August 2021. Human Mt-cfDNA and nuclear-cfDNA (Nu-cfDNA) copy numbers were estimated by quantitative polymerase chain reaction. Variables associated with PTB and 2-month sputum culture-positivity, indicating poor treatment response, were assessed using logistic regression. Among 97 patients with PTB, 64 with LTBI, and 51 with NTM-LD, Mt-cfDNA levels were higher in patients with PTB than in LTBI (p=0.001) or NTM-LD (p=0.006). In the Mycobacterium tuberculosis-infected population, Mt-cfDNA levels were highest in smear-positive PTB patients, followed by smear-negative PTB (p<0.001), and were lowest in LTBI persons (p=0.009). A Mt-cfDNA, but not Nu-cfDNA, level higher than the median helped differentiate culture-positive PTB from culture-negative PTB and LTBI (adjusted OR 2.430 [95% CI 1.139-5.186], p=0.022) and differentiate PTB from NTM-LD (adjusted OR 4.007 [1.382-12.031], p=0.011). Mt-cfDNA levels decreased after 2 months of treatment in PTB patients (p=0.010). A cutoff Mt-cfDNA level greater than 62.62 x 106 copies/μL-plasma was associated with a 10-fold risk of 2-month culture-positivity (adjusted OR 9.691 [1.046-89.813], p=0.046). Elevated Mt-cfDNA levels were associated with PTB disease and failed sputum conversion at 2 months in PTB patients, and decreased after treatment.

Characterizing and correcting immune dysfunction in non-tuberculous mycobacterial disease.

Non-tuberculous mycobacterial pulmonary disease (NTM-PD) is a chronic, progressive, and growing worldwide health burden associated with mounting morbidity, mortality, and economic costs. Improvements in NTM-PD management are urgently needed, which requires a better understanding of fundamental immunopathology. Here, we examine temporal dynamics of the immune compartment during NTM-PD caused by Mycobacterium avium complex (MAC) and Mycobactereoides abscessus complex (MABS). We show that active MAC infection is characterized by elevated T cell immunoglobulin and mucin-domain containing-3 expression across multiple T cell subsets. In contrast, active MABS infection was characterized by increased expression of cytotoxic T-lymphocyte-associated protein4. Patients who failed therapy closely mirrored the healthy individual immune phenotype, with circulating immune network appearing to 'ignore' infection in the lung. Interestingly, immune biosignatures were identified that could inform disease stage and infecting species with high accuracy. Additionally, programmed cell death protein 1 blockade rescued antigen-specific IFN-γ secretion in all disease stages except persistent infection, suggesting the potential to redeploy checkpoint blockade inhibitors for NTM-PD. Collectively, our results provide new insight into species-specific 'immune chatter' occurring during NTM-PD and provide new targets, processes and pathways for diagnostics, prognostics, and treatments needed for this emerging and difficult to treat disease.

LBODP105 A Case of Significantly Increased Levothyroxine Requirement With Rifampin Therapy

Abstract Introduction Rifampin has a wide range of drug interactions through increased hepatic microsomal enzyme activity. We are reporting a case of a patient with post-surgical hypothyroidism on stable thyroid hormone replacement therapy who required significantly higher doses of levothyroxine after starting rifampin. Case Report Patient is a 78-year-old woman with history of Papillary Thyroid Cancer (PTC) in remission status post thyroidectomy in 1994 and radioactive iodine therapy in 1997. Patient had been on a stable dose of Levothyroxine of 75-88mcg daily until a visit in January 2013 when her TSH was found to be 39 despite compliance with levothyroxine. Further history revealed that she was diagnosed with Mycobacterium Avium Intracellulare (MAI) infection of the lungs for which she was given rifampin therapy. Her Levothyroxine dose was progressively increased to 150mcg daily. She received rifampin therapy for 18 months, from August 2012 until April 2013. Her Levothyroxine dose was later changed to average 139 mcg /day based on TSH levels and continued to be the same through the rifampin course. In April 2014, and following discontinuation of rifampin, Levothyroxine was decreased to 100mcg daily and subsequently 75mcg daily. During a relapse of MAI in March 2016, her levothyroxine dosage was similarly again increased to 125mcg daily for TSH of 24.58. In June 2017, rifampin was discontinued after completion of second course of MAI treatment, and Levothyroxine dose decreased to 88 mcg daily, and subsequently 75 mcg in September 2017, and average daily 64mcg most recently given age and long-term remission with target mid normal TSH. Discussion Rifampin is used to treat active tuberculosis and MAI infection among other uses. It is a hepatic enzyme inducer which significantly interacts with other drugs. It has been reported previously to cause hypothyroidism in patients with underlying thyroid disorder and increased serum TSH while on levothyroxine, but its impact range on thyroid function has not been clearly described. Our patient was on stable levothyroxine dose following thyroidectomy, and required almost a 100% increase of levothyroxine dose when started on rifampin therapy, returning to baseline levothyroxine requirements off rifampin. This case highlights the severe hypothyroidism and significant impact on levothyroxine dose requirements following rifampin therapy, and the importance of close thyroid function monitoring in patients with hypothyroidism and on rifampin, especially in context of post-surgical hypothyroidism. Presentation: No date and time listed

LBODP022 A Rare Case Of Hypercalcemia: Mycobacterium Avium Complex Induced Hypercalcemia

Abstract Background Primary hyperparathyroidism and malignancy accounts for 90% of cases of hypercalcemia. Other causes of hypercalcemia are granulomatous diseases of which tuberculosis and sarcoidosis account for most. We report on a patient with acquired immunodeficiency syndrome (AIDS) presenting with new-onset hypercalcemia secondary to mycobacterium avium complex (MAC) infection. Clinical Case A 36-year-old man diagnosed with HIV-1/AIDS on ART presented to the hospital 3 months after initial diagnosis with worsening abdominal pain, nausea and vomiting, cough, weight loss and night sweats. He had presented to an outside facility with similar complaints, he had EGD done, was started on Augmentin and Azithromycin, and was awaiting biopsy results. On arrival he was afebrile and without palpable lymphadenopathy. He was found to have a high serum calcium (12.4 mg/dL, n 8.6-10.2 mg/dL) and acute kidney injury (AKI) (creatinine 1.7 mg/dL, n 0.6-1.3 mg/dL). His CD4 count had increased from 17 at time of diagnosis to 80 cells/μL (n 443-1,471 cells/μL). Workup for hypercalcemia revealed an elevated phosphorus (5.2 mg/dL, n 2.5-5. 0 mg/dL), low PTH (&amp;lt;1 pg/mL, n 12-88 pg/mL), elevated 1,25 Vit D level (112 pg/ml, n 20- 79 pg/ml), low PTHrP (8 pg/ml, n 14-27 pg/ml). TSH was mildly elevated (8 uIU/ml, n 0.35-5.50 uIU/ml) with normal free T4 levels. CT scan done on admission revealed bulky retroperitoneal and mesenteric root adenopathy with hepatosplenomegaly initially concerning for lymphoma. Patient was started on intravenous hydration and bisphosphonate was administered. He underwent laparoscopic lymph node biopsy and bronchoscopy with pathology report showing numerous acid-fast organisms, negative for malignancy. AFB culture was positive for MAC. Prednisone was started after biopsy with improvement in serum calcium (calcium 9.4 mg/dL). He was treated with Azithromycin and Ethambutol and discharged home a week after. Conclusion Granulomatous diseases like MAC, an AIDS-defining illness, cause hypercalcemia via activation of macrophages which express extrarenal 1- alpha -hydroxylase. It converts vitamin D to its active form 1,25(OH)2 vitamin D causing its excess, leading to hypercalcemia. Other potential causes of hypercalcemia such as malignancy must be ruled out as seen in our patient who had classic B symptoms with imaging suggestive of lymphoma. Treatment of hypercalcemia in granulomatous disease is aimed at treatment of the underlying disorder. It responds well to glucocorticoids and bisphosphonates. Presentation: No date and time listed

Pulmonary Granulomas and Mycobacterial Infection: Concordance between the Results of Special Stains Performed on Lung Tissue Sections and Tissue Cultures.

The most common cause of infectious pulmonary granulomas worldwide is Mycobacterium tuberculosis. The diagnosis is based on clinical presentation, histopathologic findings, detection of acid-fast bacilli (AFB) in tissue or sputum using special stains, and/or isolation of mycobacteria in cultures or via PCR-based methods. Different studies have shown that high levels of discrepancy exist between these diagnostic approaches in lung tissue specimens. To assess the degree of concordance between the results of special stains and cultures on lung tissue specimens in the diagnosis of mycobacterial infections. Eighty-seven patients with a diagnosis of granulomas (necrotizing and non-necrotizing) on lung tissue specimens were identified. Cohen's kappa was used to measure the general concordance between the results of the histopathological examination (special stains) and bacteriological tissue cultures. With Kinyoun acid-fast stains, 8/48 (16.7%) cases were positive for AFB. With FITE stains, 10/57 (17.5%) cases were positive for AFB. There was strong agreement between Kinyoun acid-fast and FITE stains (Kappa = 0.806; p-value &lt; 0.001). Tissue cultures were performed on 38/87 cases (43.7%), and 10/38 (26.3%) of the cultures were positive for mycobacteria. There was no concordance between Kinyoun acid-fast stains or FITE stains and tissue cultures results. Our observations represent an initial step in the process of reviewing the two methods used at our institution to diagnose mycobacterial infections on lung tissue specimens and highlight the need of incorporating more advanced diagnostic methods such as PCR to confirm mycobacterial infections and improve patient management. Importantly, species-level identification of mycobacteria is necessary to guide treatment.

A RARE CASE OF DISSEMINATED MYCOBACTERIUM AS THE CAUSE OF RECURRENT PNEUMOTHORAX

A RARE CASE OF DISSEMINATED MYCOBACTERIUM AS THE CAUSE OF RECURRENT PNEUMOTHORAX

A CASE OF MYCOBACTERIUM AVIUM COMPLEX PULMONARY INFECTION WITH SEVERE EOSINOPHILIA TREATED WITH MEPOLIZUMAB

A CASE OF MYCOBACTERIUM AVIUM COMPLEX PULMONARY INFECTION WITH SEVERE EOSINOPHILIA TREATED WITH MEPOLIZUMAB

SWYER JAMES: A SHIFT IN THE DIAGNOSIS

SWYER JAMES: A SHIFT IN THE DIAGNOSIS

S3402 Enterocolitis Caused by Mycobacterium Avium Complex in an HIV-Infected Patient

Introduction: Diarrhea in patients with human immunodeficiency virus (HIV) can be due to a variety of etiologies including infection, malignancy, and antiretroviral therapy (ART). With increased use of ART, diarrhea due to opportunistic infections has become less common. Here we report a rare case of chronic diarrhea due to Mycobacterium avium complex (MAC) infection involving the duodenum, colon, and rectum of a patient with advanced HIV. Case Description/Methods: A 41-year-old man with HIV infection diagnosed two years earlier presented with progressively worsening diarrhea. Two months prior, his CD4 count was stable at 50 cells/uL and his HIV level was undetectable while on dolutegravir/lamuvidine. He had history of MAC mycobacteremia under treatment with ethambutol, azithromycin, and rifabutin. He also had cytomegalovirus (CMV) viremia treated with valganciclovir. He reported compliance with the above medications. He had eight-month history of frequent, watery diarrhea associated with malaise, nausea, bloating, abdominal pain, and weight loss. He was hospitalized for severe malnutrition and electrolyte abnormalities. Evaluation of his diarrhea included negative C. difficile toxin, enteric pathogen panel, and ova and parasite exam. CMV was detected in the blood at 17,000 IU/mL and HIV viral load was 6,166 IU/mL. Esophagogastroduodenoscopy was performed and revealed diffuse erythema and edema affecting the mucosa of the entire duodenum with associated villous blunting and fissuring (Figure A). Flexible sigmoidoscopy revealed normal appearing mucosa to the level of the ascending colon. Pathology from duodenal biopsies showed extensive histiocytic inflammation with presence of acid-fast bacillus organisms (Figures B and C). Random biopsies from the colon and rectum showed similar findings and no evidence of CMV. Acid-fast bacillus blood cultures grew Mycobacterium avium-intracellulare. His MAC treatment was changed to amikacin, linezolid, rifampin, and ethambutol with subsequent improvement in his diarrhea. Discussion: Gastrointestinal tract involvement by MAC is usually part of a disseminated MAC infection in patients with advanced HIV, especially those with CD4 lymphocyte counts < 50 cells/uL. The duodenum is most often affected, followed by the rectum. We report this case to raise awareness that MAC enterocolitis remains an important etiology of chronic diarrhea in patients with advanced HIV.Figure 1.: A, EGD showing duodenal involvement by MAC causing diffuse erythema and edema with villous blunting and fissuring. B, H&E stain of duodenal mucosa with extensive histiocytic inflammation. C, Ziehl-Neelsen stain of duodenal mucosa with acid-fast bacillus positive organisms consistent with Mycobacterium avium complex.

Treatment of Nontuberculous Mycobacterial (NTM) Pulmonary Infection in the US Bronchiectasis and NTM Registry: Treatment Patterns, Adverse Events, and Adherence to American Thoracic Society/Infectious Disease Society of America Treatment Guidelines.

Among 1038 participants with pulmonary Mycobacterium avium complex and 120 with Mycobacterium abscessus enrolled in the US Bronchiectasis and NTM Research Registry, less than half received antibiotic therapy in the 24 months before registry enrollment, of which less than half were guideline based. Adverse effects occurred in 21% of therapy recipients, of whom 33% discontinued therapy.

The unique diagnostic and management challenge of a patient with concomitant anti-interferon-gamma autoantibody associated immunodeficiency syndrome, IgG4-related disease, and treatment refractory, disseminated mycobacterium avium complex infection

BackgroundAnti-interferon-gamma autoantibody-associated immunodeficiency syndrome is a rare and underrecognized adult onset immunodeficiency syndrome associated with severe opportunistic infections such as disseminated nontuberculous mycobacterium. Few cases have documented a relationship with IgG4-related disease. Concomitant diagnoses of these diseases present a diagnostic and management challenge.Case presentationA 61 year old man of Southeast Asian descent with pulmonary mycobacterium avium complex infection presented to our hospital system with a new skin rash and worsening lymphadenopathy. He was eventually diagnosed with IgG4-related disease through excisional nodal biopsy. He was managed with immunosuppressive treatment with prednisone, rituximab and cyclophosphamide. He later re-presented with disseminated mycobacterium avium complex infiltration of his joints, bones and prostate. Original titers of anti-interferon-gamma autoantibodies were falsely negative due to being on immunosuppressive therapy for his IgG4-related disease. However, anti-interferon-gamma autoantibody titers were re-sent after immunosuppression was held and returned strongly positive.ConclusionsThis case reviews diagnostic criteria and discusses management strategies with existing challenges in treating a patient with concomitant adult onset immunodeficiency syndrome, IgG4-related disease and a disseminated mycobacterial avium complex infection.

Treatment strategies with alternative treatment options for patients with Mycobacterium avium complex pulmonary disease.

Diseases caused by Mycobacterium avium complex (MAC) infection in the lungs are increasing worldwide. The recurrence rate of MAC-pulmonary disease (PD) has been reported to be as high as 25-45%. A significant percentage of recurrences occurs because of reinfection with a new genotype from the environment. A focus on reducing exposure to MAC organisms from the environment is therefore an essential component of the management of this disease as well as standard MAC-PD treatment. A macrolide-containing three-drug regimen is recommended over a two-drug regimen as a standard treatment, and azithromycin is recommended rather than clarithromycin. Both the 2007 and 2020 guidelines recommend a treatment duration of MAC-PD of at least one year after the culture conversion. Previous clinical studies have reported that ethambutol could prevent macrolide resistance. Furthermore, the concomitant use of aminoglycoside, amikacin liposomal inhalation, clofazimine, linezolid, bedaquiline, and fluoroquinolone with modification of guideline-based therapy has been studied. Long-term management of MAC-PD remains challenging because of the discontinuation of multi-drug regimens and the acquisition of macrolide resistance. Moreover, the poor compliance of guideline-based therapy for MAC-PD treatment worldwide is concerning since it causes macrolide resistance. Therefore, in this review, we focus on MAC-PD treatment and summarize various treatment options when standard treatment cannot be maintained, with reference to the latest ATS/ERS/ESCMID/IDSA clinical practice guidelines revised in 2020.

Reduced phagocytic activity of human alveolar macrophages infected with Mycobacterium avium complex

IntroductionCo-infection of nontuberculous mycobacteria (NTM) with other bacteria is associated with increased frequency of hospitalization and reduced quality of life. However, the clinical significance of co-infection with NTM and other bacteria remains unclear. Here, we investigated the distribution of alveolar macrophage populations, characterized their phagocytic function in bronchoalveolar lavage fluid (BALF), and assessed the bactericidal function of macrophages infected with NTM using cell lines. MethodsBALF samples were prospectively obtained from 30 patients with suspected NTM lung disease to evaluate phagocytic activities of macrophages using immunostaining. Bactericidal activities of Staphylococcus aureus (S. aureus) and Mycobacterium intracellulare (M. intracellulare)-infected or -non-infected macrophages were evaluated using macrophage cell lines. ResultsEleven patients with Mycobacterium avium complex (MAC) infection and 19 patients with chronic lower respiratory tract infections except for NTM infection (controls) were enrolled. The percentage of non-polarized (HLA-DR+, CD40−, and CD163−) macrophages in patients infected with MAC was significantly higher than that in controls; non-polarized macrophages demonstrated an impaired ability to phagocytose S. aureus. In vitro experiments revealed higher intracellular S. aureus colony-forming unit counts and proinflammatory cytokine levels in M. intracellulare-infected macrophages than in non-NTM-infected macrophages. Electron microscopy showed morphologically damaged macrophages and M. intracellulare and S. aureus growing in the same phagosome. ConclusionThe proportion of alveolar macrophages (HLA-DR+, CD40−, and CD163−) with impaired phagocytosis increased in MAC-infected individuals. M. intracellulare-infected macrophages reduced bactericidal activity in vitro. Dysfunction of alveolar macrophages may contribute to persistent infection by other bacteria, leading to MAC lung disease progression.

Disseminated Mycobacterium chimaera infection in a patient with adult-onset immunodeficiency syndrome: case report

BackgroundPatients with adult-onset immunodeficiency syndrome due to anti-interferon-γ autoantibodies (AIGAs) are susceptible to disseminated Mycobacterium avium complex (MAC) infections. M. chimaera, a newly identified MAC species, is distinguished from the others due to the reduced virulence. Previous cases of disseminated M. chimaera infection have been linked to cardiothoracic surgery. Reports of disseminated M. chimaera in patients without a history of cardiothoracic surgery are rare.Case presentationA 57-year-old Asian man, previously healthy, presented with fever, dry cough, exertional dyspnea, and decreased appetite. The delayed resolution of pneumonia despite antibiotic treatment prompted further imaging studies and biopsies from the lung and lymph node. The fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) demonstrated intense uptake in lung consolidations and diffuse lymphadenopathy. Cultures of the specimens obtained from sputum, blood, stool, lung tissue, and lymph node grew M. chimaera. Further immunological evaluation disclosed the presence of neutralizing AIGAs, which possibly led to acquired immunodeficiency and disseminated M. chimaera infection.ConclusionsWe herein present the first case of adult-onset immunodeficiency due to AIGAs complicated with disseminated M. chimaera infection. Further immunological evaluation, including AIGAs, may be warranted in otherwise healthy patients who present with disseminated mycobacterial infection.

Incidence of Nontuberculous Mycobacterial Pulmonary Infection, by Ethnic Group, Hawaii, USA, 2005-2019.

To further clarify differences in the risk for nontuberculous mycobacterial pulmonary infection (NTM-PI) among ethnic populations in Hawaii, USA, we conducted a retrospective cohort study among beneficiaries of Kaiser Permanente Hawaii (KPH). We abstracted demographic, socioeconomic, clinical, and microbiological data from KPH electronic health records for 2005–2019. An NTM-PI case-patient was defined as a person from whom >1 NTM pulmonary isolate was obtained. We performed Cox proportional hazards regression to estimate incidence of NTM-PI while controlling for confounders. Across ethnic groups, risk for NTM-PI was higher among persons who were underweight (body mass index [BMI] <18.5 kg/m2). Among beneficiaries who self-identified as any Asian ethnicity, risk for incident NTM-PI was increased by 30%. Low BMI may increase susceptibility to NTM-PI, and risk may be higher for persons who self-identify as Asian, independent of BMI.

Cutaneous nontuberculous mycobacterial infections in Japan: Review of the Japanese literature.

Nontuberculous mycobacteria cause a wide range of infections, including cutaneous infections, in both immunocompromised and immunocompetent patients. Although pulmonary nontuberculous mycobacterial infections have increased significantly in Japan in recent years, there is less evidence on clinical and microbiological characteristics of cutaneous nontuberculous mycobacterial infections in Japan. We reviewed 86 Japanese cases reported between July 2016 and November 2021 and analyzed them in conjunction with the eight patients from our institution who were diagnosed with cutaneous nontuberculous mycobacterial infections by culture between 2015 and 2021. In the aggregate series, the average patient age was 60 years, and the ratio of immunocompromised hosts was 53%, both of which were higher than those in previous reports from other countries. No female predominance was observed, unlike in pulmonary nontuberculous mycobacteria infections. Rapidly growing mycobacteria accounted for 58% of the cases (n=54), whereas slowly growing mycobacteria for 43% (n=40). Mycobacterium marinum (also known as Mycobacteroides marinum) (n=20, 21%) was the most common cause, followed by Mycobacterium chelonae (n=18, 19%), Mycobacterium abscessus (also known as Mycobacteroides abscessus) (n=15, 16%), and Mycobacterium ulcerans (n=11, 12%). While clinical appearance was variable, M ulcerans infections usually presented with ulcers, while nodules were common among infections caused by M chelonae and M marinum. Disseminated infections involving multiple organs were observed in 23 patients (24%). Thirty-two cases (30%) were preceded by exposure, including raising or handling fish, trauma, and invasive medical procedures. Most patients were treated with more than two antibiotics and responded to therapy.

Clinical Features and Treatment Outcomes of Pulmonary Mycobacterium avium-intracellulare Complex With and Without Coinfections.

Coinfections are more common in patients with cystic fibrosis and bronchiectasis. Infiltrates on imaging studies are seen more commonly in patients with coinfections, but coinfections did not affect treatment outcomes of pulmonary Mycobacterium avium complex.