Nontuberculous Mycobacteria Infection In Patients Research Articles

Molecular mechanism analysis of nontuberculous mycobacteria infection in patients with cystic fibrosis.

Aim: This study aims to explore the molecular mechanisms of cystic fibrosis (CF) complicated with nontuberculous mycobacteria (NTM) infection. Materials & methods: Expression profiles of CF with NTM-infected patients were downloaded from GEO database. Intersection analysis yielded 78 genes associated with CF with NTM infection. The protein-protein interaction (PPI) network and the functions of hub genes were investigated. Results: Five hub genes (PIK3R1, IL1A, CXCR4, ACTN1, PFN1) were identified, which were primarily enriched in actin-related biological processes and pathways. Transcription factors RELA, JUN, NFKB1 and FOS that regulated hub genes modulated IL1A expression, while 21 other transcription factors regulated CXCR4 expression. Conclusion: In summary, this study may provide new insights into the mechanisms of CF with NTM infection.

Tuberculosis and Nontuberculous Mycobacterial Infections in Patients with Spondyloarthritis: A Population-Based Study.

Background and Objectives: Tuberculosis is caused by Mycobacterium tuberculosis (MTB), while nontuberculous mycobacteria (NTM) encompass a group of mycobacterial species that are distinct from the MTB complex and leprae. Spondyloarthritis (SpA) is a group of chronic inflammatory diseases with shared clinical characteristics and is treated with biological agents; however, their use may elevate the risk of MTB and NTM infections. This study aimed to compare the incidence and risk of MTB and NTM infections in patients with SpA, including ankylosing spondylitis (AS) and psoriatic arthritis (PsA), using a population-based approach. Materials and Methods: This study included 2333 patients with SpA and 9332 age- and sex-matched controls from the Korea National Health Insurance Service-National Sample Cohort database from 2002 to 2019. The patients were identified using the International Classification of Diseases-10 codes for AS, PsA, MTB, and NTM. Results: The results showed that a negligible percentage of patients with SpA developed NTM (0.002%) and MTB (0.016%), with no significant difference in the incidence rate ratio (IRR) compared to controls. Among patients with SpA treated with biologics, the IRRs for NTM and MTB were 5.66 and 3.069, respectively; however, these were not statistically significant. No cases of NTM or MTB infection were reported in female patients with SpA treated with biologics. In both the SpA patient group and the control group, the incidence of MTB was higher in individuals over 60 years old compared to those under 60 years old. Cox proportional hazard analysis revealed a significant adjusted hazard ratio of 1.479 for MTB in patients with SpA after adjusting for age, sex, smoking history, insurance level, and comorbidities. However, this significance was not maintained when biological therapy was further adjusted. Conclusions: Our study indicated that the risks of NTM and MTB infection are not elevated in patients with SpA. Although biological use may potentially increase the risk of MTB infection, it does not lead to a significant increase in incidence rates. Proactive screening for latent tuberculosis and adequate prophylaxis using biologics can effectively manage the risk of NTM and MTB infections.

The frequency and related factors of non-tuberculosis mycobacteria infections among patients with cystic fibrosis.

Non-tuberculous mycobacteria (NTM) can cause chronic lung infection particularly in patients who have structural lung disease such as cystic fibrosis (CF). We evaluated the incidence and management of NTM infections in patients with CF in our center. A retrospective cohort study was carried out on CF patients having at least one positive NTM isolate between 2012 and 2020. Ten patients (2.1%) had at least one positive NTM culture from respiratory samples. All of them were vaccinated with Bacille Calmette-Guérin (BCG) vaccine, which is in the national vaccination program in our country. Eight patients had the Mycobacterium abscessus complex, one had Mycobacterium avium, and one had Mycobacterium szulgai growth in their respiratory samples. Three patients had transient NTM infection, two had persistent, and five had active NTM infection (NTM pulmonary disease). Patients with NTM pulmonary disease received antibiogram-directed antimycobacterial therapy. In patients with NTM pulmonary disease, the median ppFEV1 and BMI decreased by 17% and 1%, respectively, at the time of the first NTM isolation when compared with the values one year before the first NTM isolation. Culture conversion was not seen in any patient infected with Mycobacteriunm abscessus complex. The NTM infection incidence is lower in our country than in those countries where the BCG vaccine is not routinely applied. The BCG vaccine may be a protective factor for NTM infection. Further studies are needed about the prevalence of NTM infections, facilitating and protective factors, and appropriate management of NTM infections in patients with CF.

Bronchial Brushing and Diagnosis of Pulmonary Nontuberculous Mycobacteria Infection

Background: The optimal bronchoscopy procedure for diagnosis of pulmonary nontuberculous mycobacteria (NTM) infection is unclear. Objective: This study investigated the usefulness of bronchial brushing in bronchoscopy for diagnosis of pulmonary NTM infection in patients with suspected NTM lung disease and nodular bronchiectasis on chest computed tomography (CT) images. Methods: Bronchoscopy was prospectively performed for 69 patients with clinically suspected pulmonary NTM infection on chest CT from December 2017 through December 2019. Before and after bronchial brushing, bronchial washing was performed with 20 or 40 mL of normal sterile saline at the same segmental or subsegmental bronchi. Before and after bronchial brushing, samples of the washing fluid (pre- and postbrushing samples) and brush deposits (brush samples) were obtained and cultured separately. Results: NTM was detected in 37 of the 69 (53.6%) patients (Mycobacterium avium in 27, Mycobacterium intracellulare in 7, M. abscessus in 2, and M. kansasii in 2). NTM was detected in 34 (49.3%) prebrushing samples, in 27 (39.1%) postbrushing samples, and in 20 (29.0%) brush samples from the 69 patients. In 2 (2.9%) patients, NTM was detected only in postbrushing samples; in 1 (1.4%) patient, NTM was detected only in a brush sample. As compared with bronchial washing only, additional bronchial brushing increased the NTM culture-positive rate by 4.3% (3/69). Bronchial brushing caused bleeding, requiring hemostasis in 5 (7.2%) patients. Conclusion: Additional bronchial brushing increased the NTM culture-positive rate by only 4.3% (3/69), as compared with bronchial washing alone. Thus, the usefulness of brushing appears to be limited.

Nontuberculous mycobacterial infection in rheumatoid arthritis patients: a single-center experience in South Korea.

Nontuberculous mycobacteria (NTM) infection has been increasing worldwide in both general population and immunocompromised patients, which has also been reported in rheumatoid arthritis (RA) patients. This study aimed to identify the incidence and clinical characteristics of NTM infection in RA patients living in tuberculosis (TB) infection endemic area.We performed a retrospective analysis of NTM infection cases in our RA registry at a tertiary referral center from January 1995 to December 2013. The clinical features of them were compared to those of 52 TB infection patients from same registry.Among 1,397 patients with RA, NTM infection was newly developed in 26 patients and the incidence of NTM infection was 164.8 per 100,000 patient-years. The Mycobacterium avium complex was the most frequent isolate (76.9%). None of the NTM infections had extrapulmonary involvement, which was rather common in TB infection (26.9%). Patients with NTM infection were older, received higher cumulative steroid doses, and had higher rates of past TB infection history and concomitant interstitial lung disease (ILD) than cases with TB infection.In South Korea, NTM infection is not rare in RA patients, and infection rates are growing. Physicians should be cautious about NTM infection in patients with a history of TB infection or concomitant ILD, even living in TB endemic area.

Trends in the Prevalence of Non-TB Mycobacterial Infection in Patients With Non-Cystic Fibrosis Bronchiectasis in South Korea, 2012-2016

Background Epidemiological data regarding the prevalence of nontuberculous mycobacteria (NTM) infection in patients with non-cystic fibrosis (CF) bronchiectasis are lacking. Methods The prevalence of non-CF bronchiectasis, and that of coexisting NTM infection in bronchiectasis patients, were investigated using data from the Korean Health Insurance Review and Assessment Service. Results From 2012 to 2016, 25,447 cases of non-CF bronchiectasis were extracted from a total of 5,885,483 individuals ≥ 18 years of age. The frequency of coexisting NTM infection in patients with bronchiectasis gradually increased each year, even though the estimated prevalence of bronchiectasis did not change much during that period. This resulted in a gradual increase in the prevalence of coexistence of NTM infection and non-CF bronchiectasis (12.8 cases / 100,000 population in 2012, 16.9 in 2013, 18.4 in 2014, 24.5 in 2015, and 25.2 in 2016, respectively). Furthermore, the presence of NTM infection in bronchiectasis patients was associated with increased healthcare resource use. [Figure 1] Conclusions Results of the present study demonstrated that approximately 5% of patients with non-CF bronchiectasis had coexisting NTM infection, the prevalence of coexisting NTM infection exhibited an increasing trend every year, and the presence of NTM infection was associated with higher healthcare resource use in South Korea.

Radiologic Characteristics of Non-tuberculous Mycobacteria Infection in Patients with Bronchiectasis

Non-tuberculous mycobacteria pulmonary disease (NTM-pd) commonly complicates bronchiectasis. However, clinical and radiological features of NTM-pd and bronchiectasis are very similar. We aimed to develop a radiologic prediction tool for bronchiectasis to identify NTM-pd. We reviewed clinical, laboratory and radiological data in patients with bronchiectasis. Radiologic features on CT scans and the individual components of the Bhalla scoring system were compared between people with and without NTM-pd. Logistic regression and receiver-operating curve (ROC) analysis were performed to predict NTM-pd. People with NTM-pd had more pulmonary segments with bronchiectasis (13 ± 5 vs. 11 ± 5, p = 0.03), presence of mucus plugging (47% vs. 19%, p < 0.0001) and tree in bud infiltrates (53% vs. 28%, p = 0.004). The total modified- Bhalla score was worse among people with NTM-pd (median [IQR] 11[9,13] vs. 9[8,12], p = 0.03). Logistic regression identified the number of pulmonary segments involved, presence of bullae, consolidations, and a total score of 10 or more to be independently associated with presence of NTM-pd. ROC analysis with radiographic variables only identified an AUC of 0.706 (95% CI 0.644-0.762). When people with chronic Pseudomonas infection were excluded from the ROC analysis, prediction for NTM was improved: AUC = 0.87 (95% CI 0.796-0.945). Radiological features together with advanced age and female gender may predict NTM-pd among people with bronchiectasis. Infection with Pseudomonas aeruginosa may resemble NTM radiographically, and this prediction rule may better differentiate people with and without NTM-pd when Pseudomonas infection is not present.

Disseminated Mycobacterium avium complex infection mimicking malignancy in a patient with anti-IFN-\u03b3 autoantibodies: a case report

BackgroundDisseminated nontuberculous mycobacteria (NTM) infections occur mostly in immunocompromised patients. Therefore, it is difficult to diagnose disseminated NTM infections in patients without history of immunocompromised diseases or using immunosuppressant. Patients with anti-interferon-γ (IFN-γ) autoantibodies are vulnerable to intracellular infections, such as disseminated NTM. Currently, there is no widely used and efficient technique for the detection of anti-IFN-γ autoantibodies. Herein, we report a case of an apparently healthy patient with disseminated Mycobacterium avium complex (MAC) infection who tested positive for anti-IFN-γ autoantibodies.Case presentationA 64-year-old non-immunocompromised and apparently healthy Asian male presented to the emergency department with complaints of progressive chest pain for about 6 months and weight loss. A bulging tumour was found in the anterior chest wall. Chest computed tomography showed a lung mass over the right lower lobe and an osteolytic lesion with a soft tissue component at the sternum. Sonography-guided biopsies for the osteolytic lesion and sputum culture confirmed the presence of disseminated MAC infection. In addition, positive test result of anti-IFN-γ autoantibodies was noted. The patient was prescribed antibiotics. The lesions over the right lower lobe and sternum attenuated following the antibiotic treatment.ConclusionDetection of anti-IFN-γ autoantibodies is important among previously healthy people with disseminated NTM infection. Presence of anti-IFN-γ autoantibodies may suggest a high risk of severe intracellular infection, such as disseminated NTM infection.

1369. Clinical Manifestations, Treatment, and Outcome of Nontuberculous Mycobacteria (NTM) Infection in Adult-Onset Immunodeficiency Associated with Anti-interferon-gamma Autoantibodies in King Chulalongkorn Memorial Hospital

BackgroundThere is an increase of anti-interferon-γ autoantibodies syndromes because it is now well recognized, especially in the Southeast Asia region. One of the clinical features is an infection caused by nontuberculous mycobacteria (NTM). NTM infection in patients with anti-interferon-γ autoantibodies is usually severe, recurrent, and disseminated. In this study, we describe the clinical characteristics, treatment, and outcome of NTM infection in patients with anti-interferon-γ autoantibodiesMethodsA retrospective cohort study was conducted at the King Chulalongkorn Memorial Hospital, Bangkok, Thailand, during 2010–2018. Demographic, clinical, and microbiological data were collected and analyzed.ResultsA total of 45 patients were enrolled in this study. Twenty-nine patients were males, and 16 patients were females. The most common clinical manifestations were fever with lymphadenopathy. The median age of the study population was 55 years. The most common organ that was infected was the lymph node (91%). Sweet’s syndrome (68%) was the most common immunological skin reaction. The proportion of infection caused by rapid-growing NTM was more prevalent than slow-growing NTM. The most common NTM was Mycobacterium abscessus (44.4%). The most common co-pathogen identified in this study was Salmonella (37.8%). All patients had positive antibody to interferon-γin the serum which was detected by enzyme-linked immunosorbent assay (ELISA) and mean optical density was 3.28. Fifty-one percent of the patients received long-term antimycobacterial therapy due to chronic active infection, new infections and relapsed. 22.2% of the patients developed a new infection during treatment. However, 28.9% of patients were completely cured of the infection during the follow-up period. The overall mortality rate was 11.1%ConclusionAdult-onset immunodeficiency with anti-interferon-γ autoantibodies is a unique clinical syndrome that has been recognized in Thailand. Treatment of this disorder requires a long duration of the combination of antimycobacterial agents. Sweet’s syndrome is an indicator of recurrence/relapse of NTM infection during the clinical course. Long-term monitoring and immunomodulator are essential for the management of this condition.Disclosures All authors: No reported disclosures.

State-of-the-Art Session: Respiratory Infections

In recent decades, there has been growing interest in the recognition and management of both bronchiectasis and nontuberculous mycobacteria (NTM) pulmonary disease. More specifically, interest in diagnosing NTM infection in patients with bronchiectasis has dramatically increased. Publication of the European Respiratory Society (ERS) guidelines and results from a number of large clinical trials have resulted in an exciting year for bronchiectasis research. Despite the increased knowledge and expanding options for disease management, a number of challenges persist. There remains a paucity of evidence to support management recommendations, which have not kept pace with the growing attention given to these diseases. To explore these limitations, Prof Chalmers summarised the reasoning behind the new guidelines. The main objectives of these two presentations were to provide an expert overview of the challenges and achievements in the management of bronchiectasis and NTM pulmonary diseases, as well as predicting future trends. Dr van Ingen called for caution when managing these diseases because neither bronchiectasis nor NTM pulmonary disease can be described as single disease entities and, therefore, cannot be treated as such. The presence of NTM pulmonary disease is often a sign of multiple underlying conditions that must be addressed in tandem with culture conversion. Likewise, bronchiectasis pathogenesis is complex and failure of antibiotic therapy to offer consistent clinical benefit suggests infection is not central to pathogenesis in all patients, and a holistic approach is required. Finally, these interactive sessions uncovered and discussed various aspects and attitudes associated with disease management and highlighted how quality of care may be closely linked to clinical outcomes.

Nontuberculous mycobacteria infection risk in medical tourism.

The increasing popularity of medical tourism among US citizens has led to the rising incidence of nontuberculous mycobacteria (NTM) infections from cosmetic surgery performed in other countries. Clinicians must be aware of these infections and the potential difficulties in treating them. The most common NTM species isolated from cutaneous infections in medical tourists is Mycobacterium abscessus. Because many NTM species are antibiotic resistant, combination therapy is needed to combat skin and soft-tissue NTM infections in patients who had cosmetic procedures performed in foreign countries.

Recent methods for diagnosis of nontuberculous mycobacteria infections: Relevance in clinical practice

Nontuberculous mycobacteria (NTM) infections are ever more important in recent years for leading causes of morbidity and mortality worldwide. Clinical appearance of Mycobacterium tuberculosis (TB) complex and NTM is same, but the treatment regimen is always different. NTM is challenging for both diagnostic and therapeutic with reason that it mimic pathological, microbiological, immunological, and radiological findings of TB. Newer molecular diagnostic methods allow for a better identification of NTM infections in patients not responding to antitubercular treatment and falsely categorized as drug-resistant TB. This article will explore the recent methods for the diagnosis and identification of NTM infections in clinical practice. In the future, the molecular-based diagnosis will significantly reduce the turnaround time of the diagnosis and thereby improving patient outcome.

Prevalence of Nontuberculous Mycobacteria Infections in Patients Diagnosed with Pulmonary Tuberculosis in Ibadan

Prevalence of Nontuberculous Mycobacteria Infections in Patients Diagnosed with Pulmonary Tuberculosis in Ibadan

Incidence and Risk Factors for Nontuberculous Mycobacteria Infection after Allogeneic Hematopoietic Cell Transplantation

Introduction:Nontuberculous mycobacteria (NTM) are ubiquitous environmental organisms that are increasingly recognized as clinically significant pathogens in the allogenic hematopoietic cell transplanted (alloHCT) population. The incidence of NTM infection post alloHCT has increased from 0.49-1.0% in early studies to 2.8-8.7% in more recent investigations, possibly due to improvements in NTM detection, varying pre-transplant conditioning regimens and regional epidemiology of different NTM species. We investigated incidence and risk factors of NTM infection after alloHCT.Methods & Patients:Medical records for 1097 consecutive patients who underwent alloHCT at Princess Margaret Cancer Centre from 2000 to 2013 were reviewed to determine the frequency, risk factors and outcomes associated with NTM infections. Clinically significant NTM infection was differentiated from colonization according to the American Thoracic Society guidelines, and was classified as pulmonary, non-pulmonary, or disseminated.Acute and chronic graft versus host disease (aGVHD and cGVHD) were diagnosed and graded using established and NIH consensus criteria respectively. The cumulative incidence of NTM was calculated considering competing risks of death. Multivariate analysis comprised Cox proportional hazards regression, modeling NTM risk. Statistical analyses were performed using EZR software (Saitama, Japan).Results:Of 1097 patients, NTM were isolated in 45 (4.1%) and judged clinically significant in 30 (2.7%). The incidence of NTM infection by competing risk analysis was 2.8% at 5 years (95% CI, 1.9-4.0%). The median (range) time to diagnosis was 343 (19-1967) days, and in 83% of patients, was diagnosed within 2 years of alloHCT. Of the 30 clinically significant NTM infections, 28 (93.3%) were pulmonary and 2 (6.7%) were disseminated. With respect to the latter group, one patient had NTM isolated from blood, while the second case was presumed disseminated based on characteristic skin findings, but with no confirmed microbiologic diagnosis. The most common species/groups isolated were Mycobacterium avium complex (n=11, 36.7%), M. xenopi (n=5, 16.7%), and M. fortuitum (n=5, 16.7%). 22/30 patients (73.3%) were on systemic immunosuppression at the time of diagnosis, and 95.7% had concurrent infections (30.4% pulmonary, 17.3% extra-pulmonary, and 47.8% both), with fungal infections occurring most frequently (53.3%).Significant risk factors (HR 95% CI) for NTM included aGVHD grades 2-4 (3.25 [1.33-7.96] p=0.036), cGVHD (3.20 [1.06-9.68] p=0.010), age (1.05 [1.02-1.07], p <0.001), and CMV viremia (4.64 [1.90-11.37] p=0.001). 76.7% of patients with clinically significant NTM had a diagnosis of cGVHD (23/30), in comparison to 47.4% (520/1097) of patients without a diagnosis of NTM infection (p=0.003), and cGVHD severity by NIH global score correlated with NTM risk. Among all patients with cGVHD, severe cGVHD was present in 39% (9/23) of NTM patients, versus 17% (89/520) of non-NTM patients (p=0.012). Pre-alloHCT diagnosis (p=0.34), conditioning regimen (p=0.81), T-cell depletion (p=0.66), HLA matching (p=0.62), or donor type (p=0.63), did not reach statistical significance.Median survival duration after a diagnosis of clinically significant NTM was 398 (range, 20-764) days, with a survival rate of 40.8±10.8% at 2 years.Conclusion:Clinically significant NTM infection after alloHCT was relatively common in our study population. GVHD (acute and chronic), age, and CMV bacteremia were significant risk factors. Given a median survival of approximately 1 year following diagnosis, NTM infection may be of greater clinical significance than previously thought. A high index of suspicion for NTM infection in patients with pulmonary symptoms, particularly within 2 years after HCT and in the presence of cGVHD, may lead to prompt diagnosis and treatment, and potentially better outcomes. DisclosuresLipton:Pfizer: Consultancy, Research Funding; Ariad: Consultancy, Research Funding; Teva: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Novartis Pharmaceuticals: Consultancy, Research Funding. Kim:Novartis Pharmaceuticals: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding.

Neutrophil CD64 for monitoring the activity of nontuberculous mycobacteria infection in patients with rheumatoid arthritis

Objective. To evaluate the utility of neutrophil CD64 as a marker for monitoring the activity of nontuberculous mycobacteria (NTM) infection in patients with rheumatoid arthritis (RA).Methods. We compared neutrophil CD64 expression in nine RA patients with NTM infection in the active and inactive phase of NTM disease chronologically. “Active phase” was here defined as present in patients admitted to hospital to receive intensive treatment for NTM, as well as outpatients with an infectious episode showing positive acid- and alcohol-fast bacillus (AFB) staining of sputa (Grade 2–3) who needed to start treatment for NTM with a multiple antibiotics regimen. The cut-off value for CD64 positivity was 2000 molecules/cell.Results. Neutrophils from patients with active-phase NTM infection expressed high levels of CD64 with a mean ± SEM of 7335 ± 784 molecules/cell. However, during the inactive phase of disease, this was significantly lower (1481 ± 103 molecules/cell, p < 0.001). The sensitivity and specificity of neutrophil CD64 to detect active-phase NTM infection was 96.3% and 84.6%, respectively. Expression of neutrophil CD64 was not affected by disease activity of the RA itself.Conclusions. Neutrophil CD64 is useful for monitoring disease activity in NTM infection of patients with RA.

Mycobacterial infections in adult patients with hematological malignancy

We retrospectively analyzed the clinical and microbiological characteristics of adult patients with hematological malignancy and nontuberculous mycobacteria (NTM) infections from 2001 to 2010. During the study period, 50 patients with hematological malignancy and tuberculosis (TB) were also evaluated. Among 2,846 patients with hematological malignancy, 34 (1.2%) patients had NTM infections. Mycobacterium avium-intracellulare complex (13 patients, 38%) was the most commonly isolated species, followed by M. abscessus (21%), M. fortuitum (18%), and M. kansasii (18%). Twenty-six patients had pulmonary NTM infection and eight patients had disseminated disease. Neutropenia was more frequently encountered among patients with disseminated NTM disease (p = 0.007) at diagnosis than among patients with pulmonary disease only. Twenty-five (74%) patients received adequate initial antibiotic treatment. Five of the 34 patients died within 30 days after diagnosis. Cox regression multivariate analysis showed that chronic kidney disease (p = 0.017) and neutropenia at diagnosis (p = 0.032) were independent prognostic factors of NTM infection in patients with hematological malignancy. Patients with NTM infection had higher absolute neutrophil counts at diagnosis (p = 0.003) and a higher 30-day mortality rate (15% vs. 2%, p = 0.025) than TB patients. Hematological patients with chronic kidney disease and febrile neutropenia who developed NTM infection had significant worse prognosis than patients with TB infection.

Intestinal involvement by Micobacterium genavense in an immunodepressed patient

Mycobacterium genavense is a nontuberculous mycobacteria that has recently been described as a cause of human pathology. 1 Casal M.M. Casal M. Atypical mycobacteria as emerging pathogens. Enf Emerg. 2000; 2 ([Spanish]): 220-230 Google Scholar This intestinal affectation causes alterations in the mucosa that make diagnosis difficult. By means of endoscopy, it is possible to detect edematous folds, loss of elasticity, and increased friability of the mucosa. It usually affects severely immunodepressed patients (CD4 <100 cells/mm3), causing up to 13% of all nontuberculous mycobacteria infections in patients with AIDS. 2 de Lastours V. Guillemain R. Mainardi J.L. et al. Early diagnosis of disseminated Mycobacterium genavense infection. Emerg Infect Dis. 2008; 14: 346-347 PubMed Google Scholar The organs most commonly affected are the small bowel, bone marrow, spleen, liver, and lymph nodes. 3 Bogdan C. Kern P. Richter E. et al. Systemic infection with Mycobacterium genavense following immunosuppressive therapy in a patient who was seronegative for human immunodeficiency virus. Clin Infect Dis. 1997; 24: 1245-1247 Crossref PubMed Scopus (29) Google Scholar This strain of bacteria can be treated by prescribing rifampicin and streptomycin and is resistant to isoniazide. 4 Shrestha Y. Ortega W. Nancy P. Matuschak G. Mycobacterium genavense: a rare pulmonary pathogen in a patient with advanced AIDS. Chest. 2006; 130: 321S Google Scholar

Non-tuberculous mycobacteria in the sputum of HIV-infected patients: infection or colonization?

It can be difficult to establish the clinical significance of the isolation of non-tuberculous mycobacteria (NTM) from the sputum of HIV-infected patients. In this observational study, we have investigated factors associated with having NTM infection. During the period of the study, 10 patients had NTM infection and 14 had NTM colonization. Factors associated with having NTM infections were: CD4 lymphocyte count <50 cells/mL (odds ratio [OR] 10; 95% confidence interval [CI] 1.4-69.3), haemoglobin <11 g/dL (OR 7.2; 95% CI 1.08-47.9), weight loss (OR 9; 95% CI 1.3-63.9), duration of symptoms for more than a month (OR 54; 95% CI 4.2-692.5), the presence of acid fast bacilli (AFB) in sputum (OR 30.3; 95% CI 2.6-348.9) and repeated positive NTM cultures in other sputum samples (OR 4.3; 95% CI 1.6-11.7). In conclusion, we must suspect NTM infection in patients with long-standing symptoms, anaemia, low CD4 lymphocyte count, several positive sputum cultures and when AFB are seen.