Comparison of Mycobacterium lentiflavum and Mycobacterium avium-intracellulare complex lymphadenitis

Diagnosis of nontuberculous mycobacterial lymphadenitis: the role of fine-needle aspiration

Nontuberculous mycobacterial lymphadenitis often presents a diagnostic challenge. This study aimed to evaluate the role of fine-needle aspiration cytology in the diagnosis of nontuberculous mycobacterial lymphadenitis in children. We conducted a retrospective review of fine-needle aspiration cytology performed in patients < 17 year-old with subacute lymphadenitis from 2003 to 2016 in a tertiary hospital in Spain. Confirmed nontuberculous mycobacterial lymphadenitis (isolation of nontuberculous mycobacterial in culture from fine-needle aspiration cytology or biopsy samples) and probable nontuberculous mycobacterial lymphadenitis ("granulomatous inflammation" in cytopathologic examinations from fine-needle aspiration cytology or biopsy and clinical-epidemiological history compatible with nontuberculous mycobacterial) were selected. Forty-one patients with nontuberculous mycobacterial lymphadenitis were included: 14 confirmed and 27 probable. Fine-needle aspiration cytology was done in all of them. For 34 patients with excised lymphadenopathy, cytopathology from fine-needle aspiration cytology was concordant with biopsy in 100% cases. Culture results were available from 78.0% (32/41) of patients with fine-needle aspiration cytology and from 85.3% (29/34) with excisional biopsy. Among 22 patients with microbiological results from fine-needle aspiration cytology and biopsy, fine-needle aspiration cytology allowed advanced results in concordance with biopsy or with positive isolation not found in biopsy in 90.1% (20/22) of patients. Sensitivity of nontuberculous mycobacterial cultures obtained by fine-needle aspiration cytology compared to biopsy was 45.5% vs. 36.4% (p = 0.07). Two patients with previous skin alterations presented fistulas after fine-needle aspiration cytology (4.9%); no other complications were described.Conclusion: Fine-needle aspiration cytology provides quick cytopathologic information and is an accurate and safe technique for the diagnosis of nontuberculous mycobacterial lymphadenitis, especially in cases with challenging work-up. What is Known: • Nontuberculous mycobacterial (NTM) infection is an important cause of subacute lymphadenitis in children. • Fine-needle aspiration cytology (FNAC) is an available technique for the diagnosis of lymphadenitis of unknown etiology. What is New: • FNAC is an accurate and safe technique for the diagnosis of NTM lymphadenitis in children. • FNAC can provide reliable samples for cytopathological studies and even a better sensitivity for microbiological culture than excisional biopsy in the study of suspected NTM lymphadenitis.

State-of-the-art treatment strategies for nontuberculous mycobacteria infections

INTRODUCTION

Non-tuberculous Mycobacteria (NTM) are a group of organisms whose importance in medicine seems to be increasing in recent times. The increasing number of patients susceptible to these diseases make it necessary to expand our knowledge of therapeutic options and to explore future possibilities for the development of a therapeutic arsenal.

AREAS COVERED

In this review, the authors provide a brief introduction about the present importance of NTM and describe the present recommendations of the available guidelines for their treatment. They include a description of the future options for the management of these patients, especially focusing on new antibiotics. The authors also look at possibilities for future therapeutic options, such as antibiofilm strategies.

EXPERT OPINION

No actual changes have been made to the current recommendations for the management of most NTM infections (except perhaps the availability of nebulized amikacin). However, it is also true that we have increased the number of available antibiotic treatment options with good in vitro activity against NTM. The use of these drugs in selected cases could increase the therapeutic possibilities. However, some problems are still present, such as the knowledge of the actual meaning of a NTM isolate, and will probably be a key part of future research.

Epidemiology of Non-Tuberculous Mycobacteria isolated from clinical specimens in Madrid, Spain, from 2013 to 2017

The epidemiology of non-tuberculous mycobacteria (NTM) in Spain is largely unknown because systematic reporting is not compulsory. The aim of our study was to describe the frequency and diversity of NTM species in our region and their distribution according to the source sample, gender, and age of the patients. We performed a multicenter study of all NTM isolated in 24 public hospitals in Madrid from 2013 to 2017. A total of 6.923 mycobacteria were isolated: 4535 (65.5%) NTM, and 2.388 (34.5%) Mycobacterium tuberculosis complex (MTB). Overall, 61 different NTM species were identified. The most frequently isolated species were Mycobacterium avium complex (47.7%), M. lentiflavum (12.2%), M. gordonae (9.2%), M. fortuitum (8.9%), and M. abscessus (3.9%). Whereas MTB cases were stable during the study period, the number of NTM isolates increased considerably from 930 isolates in 2013 to 1012 in 2017; a sharp increase occurred in the last year. The rise in NTM isolates was mostly due to M. lentiflavum, M. kansasii, and M. abscessus mainly isolated from respiratory specimens in patients older than 60. The increase in isolation rate of NTM in our region is consistent with the increasing rates reported worldwide in the last decades. The rise in NTM isolates was mainly attributed to M. lentiflavum but it also should be noted the increasing of species with high pathogenic potential such as M. kansasii and M. abscessus.

Increase in Childhood Nontuberculous Mycobacterial Infections After Bacille Calmette-Guérin Coverage Drop: A Nationwide, Population-Based Retrospective Study, Finland, 1995-2016

Background

Epidemiological data on childhood nontuberculous mycobacterial (NTM) disease is scarce and the protective effect of bacille Calmette-Guérin (BCG) vaccination remains debated. In 2006, the BCG policy in Finland changed from universal to selective. We aimed to study the effect of the BCG coverage decrease on the incidence of childhood NTM infections in Finland.

Methods

We conducted a nationwide, population-based, retrospective study of NTM notifications recorded to the National Infectious Diseases Register between 1995 and 2016 and identified native-born children aged 0-4 years infected with NTM. Poisson log-linear model was used to estimate the change in the incidence rate of cohorts born during universal or selective BCG policy between 1995 and 2015.

Results

We identified 97 native-born children aged <5 years infected with NTM (median age, 27 months; female-to-male ratio, 2:1). The most common species was Mycobacterium avium (n = 69 [71%]). The estimated incidence rates of NTM in universal-BCG and selective-BCG cohorts were 0.2 and 3.9 per 100000 person-years, respectively. The incidence rate ratio of selective-BCG cohorts compared to universal-BCG cohorts was 19.03 (95% confidence interval, 8.82-41.07; P < .001).

Conclusions

After infant BCG coverage in Finland decreased, childhood NTM infections increased drastically. As there is no other apparent cause for the increase, this indicates that BCG offers protection against childhood NTM disease. This observation adds to the understanding of childhood NTM epidemiology and might explain why the disease is emerging in some countries.

Emergence of Nontuberculous Mycobacterial Lymphadenitis in Children After the Discontinuation of Mandatory Bacillus Calmette and GuÉrin Immunization in France

Eighty-five children were diagnosed with culture-confirmed nontuberculous mycobacterial cervical lymphadenitis within the MYCOMED surveillance network from 2004 to 2013. The mean incidence sharply increased from 0.57 to 3.7 per 100,000 children per year, after the discontinuation of mandatory bacillus Calmette and Guérin immunization in 2007. Cases were documented as Mycobacterium avium (62.3%), Mycobacterium intracellulare (15.3%) and Mycobacterium lentiflavum (12.9%). Outcome was favorable in all, with or without surgery or antimycobacterial treatment.

Nontuberculous mycobacterial disease in childhood - update on diagnostic approaches and treatment

Recent studies suggest that the incidence of nontuberculous mycobacterial infections in children may be increasing. Nontuberculous mycobacterial lymphadenitis, skin and soft tissue infection, and pulmonary disease each present unique challenges in relation to diagnosis and treatment. In this update, we critically review the recent literature on the epidemiology, clinical features, diagnostic approaches and treatment of nontuberculous mycobacterial disease in children. In addition, we outline key areas warranting further research.

Risk factors of non-tuberculous mycobacterial lymphadenitis in children: a case-control study

The aim of the present study is to clarify the association between environmental exposures and non-tuberculous mycobacterial (NTM) lymphadenitis, during the last decade, in a population of children. In children up to 14 years of age in a pediatric tertiary hospital, all cases of NTM lymphadenopathy with a specific microbiological diagnosis, from January 2004 to January 2015, were reviewed. This is a case-control study (1:5 proportion), in which the prevalence of environmental factors between cases and controls was compared by means of a multivariate logistic regression analysis. A total of 24 cases were diagnosed in the aforementioned period, and 18 of them included in the case-control study. Mycobacterium avium-intracellulare was the predominant mycobacterium species isolated (83.3%). Exposure to hens showed a clear trend to be significantly associated with the disease (OR = 4.33; IC95% 0.97-19.41, p = 0.055), with no significant differences for the rest of the risk factors studied.

CONCLUSION

M. avium is still the predominant bacteria causing NTM lymphadenitis in children of our region. Contact with hens has been the only risk factor for NTM lymphadenitis detected in the present study. What is Known: • M. avium is the predominant bacteria causing NTM lymphadenitis in children of our region. • There is no consensus on which environmental factors are associated with NTM lymphadenitis in children. What is New: • The only risk factor for NTM lymphadenitis found in the present study was regular contact with hens. Contact with other farm animals was not associated to NTM lymphadenitis.

Nontuberculous Mycobacterial Infections in a French Hospital: A 12-Year Retrospective Study

Background

Nontuberculous mycobacteria (NTM) are environmental organisms associated with a range of infections. Reports of NTM epidemiology are mainly focused on pulmonary infections and isolations, and extrapulmonary infections are less frequently described.

Methods

We conducted a retrospective study of NTM infections at the Bordeaux University Hospital, France, between January 2002 and December 2013. We used the microbiologic component of the American Thoracic Society/Infectious Diseases Society of America's pulmonary NTM disease criteria to define cases of pulmonary NTM, and patients with isolates from a normally sterile site were classified as having extrapulmonary disease.

Results

In our setting, 170 patients were included. Pulmonary cases predominated (54.1%), followed by skin and soft tissue infections (22.9%), disseminated cases (10.6%), lymphadenitis (7.7%), bone and joint infections (2.9%) and the remaining 1.8% catheter-related infections. Overall, 16 NTM species were isolated. Mycobacterium avium (31.8%) and M. intracellulare (20%) were the most common species identified, followed by M. marinum (13.5%), M. kansasii (10.6%), M. xenopi (9.4%), rapidly growing mycobacteria (9.4%) and other slowly growing mycobacteria (5.3%). In general, NTM isolates were largely prevalent in people older than 50 (62.4%); patients aged 1–10 year-old exclusively yielded M. avium from lymph nodes, almost cases having being diagnosed after 2007. Among the 121 patients with complete follow-up, 78 (64.5%), 24 (19.8%), and 19 (15.7%) were cured, experienced relapse, or died, respectively.

Conclusion

In our study, extrapulmonary NTM infections represented almost half of cases, consisting mainly in skin and soft tissue infections. The increase lymphadenitis cases in children after 2007 could be linked to the cessation of mandatory BCG vaccination in France. We observed similar cure rates (64%) between pulmonary and extrapulmonary infections.

[Diagnosis of infectious lymphadenitis]

Adenitis is a common disorder requesting numerous medical specialties. Etiologies are dominated by viral and bacterial infections, and more rarely parasitic, or by neoplastic and inflammatory diseases. Nevertheless, etiology remains often unknown and invasive tests may be required. On nodal tissue sample, histological examination, culture and polymerase chain reaction (PCR) are realized. PCR has revolutionized the diagnostic approach and consequently, knowledge of infectious lymphadenopathy. Previously, staphylococcus, streptococcus and mycobacterium were the main infectious agents identified in lymph nodes. Since its use, new emergent microorganisms responsible of lymphadenitis have been identified. Bartonella henselae, responsible of cat scratch disease, is to date the infectious agent most often encountered in adenitis. Mycobacterium avium subsp. hominisuis has been recently described as responsible of children lymphadenitis. PCR has become an essential tool in the diagnostic process of infectious lymphadenitis. Here, we propose a literature review on infectious adenitis and we emphasize the diagnostic strategy of adenitis.

Disseminated Mycobacterium lentiflavum responsible for hemophagocytic lymphohistocytosis in a man with a history of heart transplantation

Mycobacterium lentiflavum is a nontuberculous, slowly growing mycobacterium usually recognized as a contaminant. Here, we report a case of disseminated M. lentiflavum infection responsible for hemophagocytic lymphohistocytosis in a heart-transplanted man.