Nontuberculous mycobacterial infection in children: a 2-year prospective surveillance study in the Netherlands

Osteomyelitis Because of Mycobacterium Xenopi in an Immunocompetent Child

We present the case of a 6-year-old, immunocompetent boy with chronic osteomyelitis of the calcaneus caused by Mycobacterium xenopi. Of note, typical histopathology was not visible on the first biopsy and developed only later over a period of 6 weeks, highlighting the difficult differential diagnosis of osteomyelitis caused by nontuberculous mycobacteria.

Inherited and acquired immunodeficiencies underlying tuberculosis in childhood

Tuberculosis (TB), caused by Mycobacterium tuberculosis (M.tb) and a few related mycobacteria, is a devastating disease, killing more than a million individuals per year worldwide. However, its pathogenesis remains largely elusive, as only a small proportion of infected individuals develop clinical disease either during primary infection or during reactivation from latency or secondary infection. Subacute, hematogenous, and extrapulmonary disease tends to be more frequent in infants, children, and teenagers than in adults. Life-threatening primary TB of childhood can result from known acquired or inherited immunodeficiencies, although the vast majority of cases remain unexplained. We review here the conditions conferring a predisposition to childhood clinical diseases caused by mycobacteria, including not only M.tb but also weakly virulent mycobacteria, such as BCG vaccines and environmental mycobacteria. Infections with weakly virulent mycobacteria are much rarer than TB, but the inherited and acquired immunodeficiencies underlying these infections are much better known. Their study has also provided genetic and immunological insights into childhood TB, as illustrated by the discovery of single-gene inborn errors of IFN-γ immunity underlying severe cases of TB. Novel findings are expected from ongoing and future human genetic studies of childhood TB in countries that combine a high proportion of consanguineous marriages, a high incidence of TB, and an excellent clinical care, such as Iran, Morocco, and Turkey.

Pathologic Findings in NEMO Deficiency: A Surgical and Autopsy Survey

Hypomorphic mutations in nuclear factor κB (NF-κB) essential modulator (NEMO), encoded by IKBKG, lead to a variable combined immunodeficiency, which puts patients at risk of early death from infectious complications. The spectrum of clinical manifestations includes inflammatory disorders, especially colitis. Because of the multiple complications of NEMO deficiency, a variety of biopsy, excisional, and autopsy materials from these patients may be subject to pathologic examination. Therefore, using samples from a cohort of patients with this disorder, we aimed to survey the pathologic spectrum of NEMO deficiency and search for correlations between specific genotypes and phenotypes. Clinical and laboratory data, mutation analysis, and pathology from 13 patients were examined, including 6 autopsies. No specific genotype-pathology correlation was identified. However, we confirmed an association between ectodermal dysplasia and inflammatory conditions. We found no characteristic pathology to identify patients with NEMO deficiency; therefore, history, physical examination, and specific infections must remain the clues to suggest the diagnosis. Variability among patients and by infection makes the pathologic recognition of NEMO deficiency challenging.

Pediatric Cutaneous Nontuberculous Mycobacterium Infections in Singapore

BACKGROUND

Nontuberculous mycobacterium (NTM) infections are rare in children, with limited published studies. The course of the disease can be variable and there are no accepted treatment guidelines for the management of NTM infections in children.

OBJECTIVE

To review a cohort of pediatric patients admitted to a tertiary pediatric hospital in Singapore for cutaneous NTM infections.

METHODS

A retrospective review was performed of all children admitted to KK Women's and Children's Hospital with cutaneous NTM infections from 2002 to 2012.

RESULTS

Sixty-seven patients with positive NTM cultures from various body sites were identified. Eight of the 67 patients (11.9%) presented with cutaneous NTM without evidence of systemic involvement. The mean age at diagnosis for these eight patients was 10 years (range 5-21 yrs). Mycobacterium abscessus was the most common NTM isolated (five patients), followed by Mycobacterium hemophilium (two patients) and Mycobacterium kansasii (one patient). Most patients presented with isolated skin abscesses. Two patients were immunocompromised. Six patients required multidrug antibiotic treatment for a median duration of 5.5 months (range 3-17 mos). The median follow-up duration was 8.5 months (range 2 wks-29 mos).

CONCLUSION

Although the incidence of cutaneous NTM is rare, the diagnosis should be considered in patients presenting with chronic wounds. Most patients require treatment with multidrug antibiotic therapy, although uncomplicated abscesses can be treated with surgical incision and drainage alone.

[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.

Non-tuberculous mycobacterial infection in hospitalized children: a case series

Non-tuberculous mycobacteria (NTM) illness is an emerging life-threatening infection, and paediatric features have not been well studied. The objective of our study was to review the NTM isolates of hospitalized paediatric patients identified at our institution and to describe the characteristics of these cases. Our retrospective chart review from 2010 to 2013 identified 45 patients with 46 positive NTM cultures. Fifteen (33%) patients had received haematopoietic cell transplant, 13 (29%) had cystic fibrosis, and six (13%) were previously healthy. Twenty-seven (59%) NTM isolates were Mycobacterium chelonae/abscessus, 14 (30%) were M. avium intracellulare, and four (9%) were M. immunogenum. The majority (65%) of cases were community-acquired, and 20 (43%) patients were treated as infection. This case series identified a predominance of M. chelonae/abscessus, and includes a substantial number of haematopoietic cell transplant patients, which reflects the changing spectrum of NTM disease as molecular diagnostics improve and quaternary care facilities provide for a larger immunocompromised population.

The management of non-tuberculous cervicofacial lymphadenitis in children: A systematic review and meta-analysis

OBJECTIVES

Cervicofacial lymphadenitis is the most common manifestation of infection with non-tuberculous mycobacteria (NTM) in immunocompetent children. Although complete excision is considered standard management, the optimal treatment remains controversial. This study reviews the evidence for different management options for NTM lymphadenitis.

METHODS

A systematic literature review and meta-analysis were performed including 1951 children from sixty publications. Generalised linear mixed model regressions were used to compare treatment modalities.

RESULTS

The adjusted mean cure rate was 98% (95% CI 97.0-99.5%) for complete excision, 73.1% (95% CI 49.6-88.3%) for anti-mycobacterial antibiotics, and 70.4% (95% CI 49.6-88.3%) for 'no intervention'. Compared to 'no intervention', only complete excision was significantly associated with cure (OR 33.1; 95% CI 10.8-102.9; p < 0.001). Complete excision was associated with a 10% risk of facial nerve palsy (2% permanent). 'No intervention' was associated with delayed resolution.

CONCLUSIONS

Complete excision is associated with the highest cure rate in NTM cervicofacial lymphadenitis, but also had the highest risk of facial nerve palsy. In the absence of large, well-designed RCTs, the choice between surgical excision, anti-mycobacterial antibiotics and 'no intervention' should be based on the location and extent of the disease, and acceptability of prolonged time to resolution.

Salivary gland diseases in children

Salivary gland diseases in children are rare, apart from viral-induced diseases. Nevertheless, it is essential for the otolaryngologist to recognize these uncommon findings in children and adolescents and to diagnose and initiate the proper treatment.

The present work provides an overview of the entire spectrum of congenital and acquired diseases of the salivary glands in childhood and adolescence. The current literature was reviewed and the results discussed and summarized.

Besides congenital diseases of the salivary glands in children, the main etiologies of viral and bacterial infections, autoimmune diseases and tumors of the salivary glands were considered. In addition to the known facts, new developments in diagnostics, imaging and therapy, including sialendoscopy in obstructive diseases and chronic recurrent juvenile sialadenitis were taken into account. In addition, systemic causes of salivary gland swelling and the treatment of sialorrhoea were discussed. Although salivary gland diseases in children are usually included in the pathology of the adult, they differ in their incidence and some­times in their symptoms. Clinical diagnostics and especially the surgical treatment are influenced by a stringent indications and a less invasive strategy. Due to the rarity of tumors of the salivary glands in children, it is recommended to treat them in a specialized center with greater surgical experience.

Altogether the knowledge of the differential diagnoses in salivary gland diseases in children is important for otolaryngologists, to indicate the proper therapeutic approach.

Skin and soft tissue infections caused by nontuberculous mycobacteria

PURPOSE OF REVIEW

Skin and soft tissues infections (SSTIs) caused by nontuberculous mycobacteria (NTM) are underrecognized and difficult to treat. Controversies exist for optimal medical management and the role of surgery. Defining the epidemiology in the environment, in animals and in healthcare aids disease prevention. This review focuses on recent advances in epidemiology, risk factors, diagnostics and therapy.

RECENT FINDINGS

The increasing consumer appetite for cosmetic and body-modifying procedures (e.g. tattooing, mesotherapy, liposuction) has been associated with rises in sporadic cases and outbreaks of NTM SSTIs. In mainstream healthcare, recent epidemiological studies have helped to quantify the increased risk of NTM infection related to anti-tumour necrosis factor-α monoclonal antibody therapy. Cervicofacial lymphadenitis in children poses management dilemmas, but recent studies and resultant algorithms have simplified decision-making. Molecular studies have led to a better understanding of the epidemiology, therapy and course of Mycobacterium ulcerans infection (Buruli ulcer) that remains prevalent in many areas including sub-Saharan Africa and southeastern Australia. Apart from molecular methods, the widespread adoption of matrix-assisted laser desorption ionization-time of flight mass spectrometry by routine laboratories has potential to simplify and expedite the laboratory identification of NTMs.

SUMMARY

An improved understanding of the epidemiology of NTM SSTIs indicates a need to apply effective infection control and ensure regulation of cosmetic and related procedures associated with nonsterile fluids. Broader access to newer diagnostic methods will continue to improve recognition of NTM disease. Along with a paucity of therapeutic agents, there is need for more reliable methods to assess susceptibility and selection of effective combination therapy.

Management of nontuberculous mycobacterial infection in the elderly

The incidence of nontuberculous mycobacteria (NTM) has increased over the last decades. Elderly people are more susceptible to NTM and experience increased morbidities. NTM incidence is expected to rise due to an increasing elderly population at least up to 2050. Given the importance of NTM infection in the elderly, an increasing interest exists in studying NTM characteristics in the aged population. In this review, we summarize the characteristics of NTM infection among elderly patients. We focus on epidemiology, clinical presentation, and treatment options of NTM in this age group. We highlight the differences in the diagnosis and treatment between rapid and slow growing mycobacterial infections. The current recommendation for treatment of NTM is discussed. We debate if in vitro susceptibility testing has a role in the treatment of NTM. Drug-drug interaction between antibiotics used to treat NTM and other medications, particularly warfarin, is another important issue that we discuss. Finally, we review the prognosis of NTM disease in elderly patients.

Comparison of Mycobacterium lentiflavum and Mycobacterium avium-intracellulare complex lymphadenitis

BACKGROUND

Mycobacterium lentiflavum is considered a rare pathogen causing nontuberculous mycobacterial (NTM) lymphadenitis.

METHODS

A multicenter, retrospective study was performed in immunocompetent children <14 years of age with microbiologically confirmed NTM lymphadenitis treated at 6 hospitals in Madrid, Spain, during 2000-2010. We compared children with M. lentiflavum and Mycobacterium avium-intracellulare complex infection.

RESULTS

Forty-five microbiologically confirmed NTM lymphadenitis patients were identified: 19 (45.2%) caused by M. avium-intracellulare complex, 17 (40.5%) by M. lentiflavum, 1 by both and 5 by other mycobacteria. Out of 17 M. lentiflavum cases, 14 were diagnosed in the past 5 years. Regarding M. lentiflavum cases, median age was 23 months. Submandibular nodes were the most frequently involved (76.5%), with multiple locations seen in 41% of the children and spontaneous drainage in 41% of them. Drug susceptibility tests were performed in 14 isolates and showed a complete susceptibility to clarithromycin and cycloserine, whereas 93% were resistant to rifampin, 33% to quinolones and full resistance to other tested antimycobacterial drugs was detected. All but 1 child required surgery and 11 were treated additionally with various drug combinations. Total resolution was achieved in 50% of children within 6 months.Compared with M. avium-intracellulare complex cases, children were younger and laterocervical nodes were significantly less frequently involved. No statistically significant differences were found related to clinical characteristics, treatment and outcome.

CONCLUSIONS

M. lentiflavum is an emerging pathogen producing NTM lymphadenitis in Madrid.

Nontuberculous mycobacterial infections in children with inborn errors of the immune system

Severe mycobacterial disease is mostly confined to patients who are immunocompromized either by acquired or inherited causes. One such genetic disorder is Mendelian Susceptibility to Mycobacterial Disease (MSMD), a hot topic within the field of primary immunodeficiency. This single gene disorder is characterized by isolated infection with mycobacteria or Salmonella due to a defect in the type-1 cytokine response. In the last two decades, ten genes have been labeled as causing MSMD when they harbor germline mutations, namely IL12B, IL12RB1, IFNGR1, IFNGR2, STAT1, IKBKG, CYBB, TYK2, IRF8 and ISG15. The mutations lead to either insufficient production of IFN-γ, or to an insufficient response to the cytokine. Current treatment options include recombinant IFN-γ and hematologic stem cell transplantation (HSCT). In the future, gene therapy, antisense-mediated exon skipping and chemical intervention in glycosylation problems may become successful alternatives. Furthermore, it is likely that many new candidate genes and pathways crucial for mycobacterial immunity will be identified.

Current trends in nontuberculous mycobacteria infections in Canadian children: A pediatric investigators collaborative network on infections in Canada (PICNIC) study

BACKGROUND

Nontuberculous mycobacteria (NTM) infections appear to be increasing in number and severity in developed countries worldwide. Surgical excision has been considered the standard treatment for NTM lymphadenitis, but the use of medical therapy seems to be increasing.

OBJECTIVE

To determine the disease characteristics as well as the current therapeutic management of NTM infections in Canadian children.

METHODS

Cases of definite or probable NTM infections were identified prospectively in children up to 18 years of age seen in 10 Canadian paediatric tertiary care centres from September 2005 to August 2006. Clinical, microbiological and pathological data were collected.

RESULTS

A total of 60 cases were identified. Data were complete for 45 patients, including 34 cases of lymphadenitis, four cases of skin and soft tissue infection, and seven cases of pulmonary NTM infection. Seventy-nine per cent of children (27 of 34) with lymphadenitis had an unsuccessful course of antibiotics before diagnosis. Sixty-eight per cent of purified protein derivative tests (15 of 22) were positive. NTM was detected in 76% of samples (29 of 38), of which 62% were Mycobacterium avium complex. All patients with lymphadenitis underwent surgical therapy and most patients (74%) also received antimicrobials.

CONCLUSIONS

Current trends indicate that the majority of the study centres are using medical therapy with variable regimen and duration as an adjunct to surgical excision in the treatment of NTM lymphadenitis. Larger numbers and longer follow-up times are needed to better evaluate the efficacy of medical therapy and outcome of disease. A randomized controlled study comparing surgical therapy alone and chemotherapy for NTM lymphadenitis is required.

[Nontuberculous mycobacterial epitrochlear adenitis]

We report the case of a 2-year-old girl referred for unilateral epitrochlear lymphadenitis caused by Mycobacterium avium. Adenitis is the most frequent presentation of non tuberculous mycobacteria in children. Typical locations are the cervical, submandibular, axillar, inguinal, mediastinal, and parotid regions. To our knowledge, this is the first observation of an epitrochlear location. The diagnosis was made by evidencing the causal bacterium but also by the exclusion of other causes such as Bartonella henselae and Mycobacterium tuberculosis infections. Treatment is based on surgical excision, which provides a cure rate of 90%. Macrolides are reserved for extended lesions and/or relapsing lesions despite surgical management.

Mycobacterium avium complex--the role of potable water in disease transmission

Mycobacterium avium complex (MAC) is a group of opportunistic pathogens of major public health concern. It is responsible for a wide spectrum of disease dependent on subspecies, route of infection and patients pre-existing conditions. Presently, there is limited research on the incidence of MAC infection that considers both pulmonary and other clinical manifestations. MAC has been isolated from various terrestrial and aquatic environments including natural waters, engineered water systems and soils. Identifying the specific environmental sources responsible for human infection is essential in minimizing disease prevalence. This paper reviews current literature and case studies regarding the wide spectrum of disease caused by MAC and the role of potable water in disease transmission. Potable water was recognized as a putative pathway for MAC infection. Contaminated potable water sources associated with human infection included warm water distribution systems, showers, faucets, household drinking water, swimming pools and hot tub spas. MAC can maintain long-term contamination of potable water sources through its high resistance to disinfectants, association with biofilms and intracellular parasitism of free-living protozoa. Further research is required to investigate the efficiency of water treatment processes against MAC and into construction and maintenance of warm water distribution systems and the role they play in MAC proliferation.

Infectious diseases in patients with IRAK-4, MyD88, NEMO, or IκBα deficiency

Autosomal recessive IRAK-4 and MyD88 deficiencies predispose affected patients to recurrent invasive pyogenic bacterial infection. Both defects result in the selective impairment of cellular responses to Toll-like receptors (TLRs) other than TLR3 and of cellular responses to most interleukin-1 receptors (IL-1Rs), including IL-1R, IL-18R, and IL-33R. Hypomorphic mutations in the X-linked NEMO gene and hypermorphic mutations in the autosomal IKBA gene cause X-linked recessive and autosomal dominant anhidrotic ectodermal dysplasia with immunodeficiency (EDA-ID) syndromes. Both of these defects impair NF-κB-mediated cellular responses to multiple receptors, including TLRs, IL-1Rs, and tumor necrosis factor receptors (TNF-Rs). They therefore confer a much broader predisposition to infections than that for IRAK-4 and MyD88 deficiencies. These disorders were initially thought to be rare but have now been diagnosed in over 170 patients worldwide. We review here the infectious diseases affecting patients with inborn errors of NF-κB-dependent TLR and IL-1R immunity.

"Mycobacterium tilburgii" infection in two immunocompromised children: importance of molecular tools in culture-negative mycobacterial disease diagnosis

"Mycobacterium tilburgii" is a nontuberculous mycobacterium that cannot be cultured by current techniques. It is described as causing disseminated disease in adults. We present the first cases of disseminated disease in 2 immunocompromised children. This paper stresses the importance of molecular techniques for correct mycobacterial identification and guidance to immunological diagnosis.

NEMO is a key component of NF-κB- and IRF-3-dependent TLR3-mediated immunity to herpes simplex virus

BACKGROUND

Children with germline mutations in Toll-like receptor 3 (TLR3), UNC93B1, TNF receptor-associated factor 3, and signal transducer and activator of transcription 1 are prone to herpes simplex virus-1 encephalitis, owing to impaired TLR3-triggered, UNC-93B-dependent, IFN-α/β, and/or IFN-λ-mediated signal transducer and activator of transcription 1-dependent immunity.

OBJECTIVE

We explore here the molecular basis of the pathogenesis of herpes simplex encephalitis in a child with a hypomorphic mutation in nuclear factor-κB (NF-κB) essential modulator, which encodes the regulatory subunit of the inhibitor of the Iκβ kinase complex.

METHODS

The TLR3 signaling pathway was investigated in the patient's fibroblasts by analyses of IFN-β, IFN-λ, and IL-6 mRNA and protein levels, by quantitative PCR and ELISA, respectively, upon TLR3 stimulation (TLR3 agonists or TLR3-dependent viruses). NF-κB activation was assessed by electrophoretic mobility shift assay and interferon regulatory factor 3 dimerization on native gels after stimulation with a TLR3 agonist.

RESULTS

The patient's fibroblasts displayed impaired responses to TLR3 stimulation in terms of IFN-β, IFN-λ, and IL-6 production, owing to impaired activation of both NF-κB and IRF-3. Moreover, vesicular stomatitis virus, a potent IFN-inducer in human fibroblasts, and herpes simplex virus-1, induced only low levels of IFN-β and IFN-λ in the patient's fibroblasts, resulting in enhanced viral replication and cell death, as reported for UNC-93B-deficient fibroblasts.

CONCLUSION

Herpes simplex encephalitis may occur in patients carrying NF-κB essential modulator mutations, due to the impairment of NF-κB- and interferon regulatory factor 3-dependent-TLR3-mediated antiviral IFN production.

First Canadian Reports of Cervical Adenitis Due to Mycobacterium Malmoense and a 10-year Review of Nontuberculous Mycobacterial Adenitis

The present report reviews a decade of experience with nontuberculous mycobacterial adenitis at a pediatric referral centre, noting that patients are often subjected to multiple ineffective antibiotic courses, and that delays in diagnosis and referral for appropriate therapy are common. Notable clinical features include a mean age of presentation of 3.4 years, a male-to-female ratio of 1:1.5 and a gradual onset of painless, unilateral cervical adenopathy. Fever was absent in most patients (77%), and the disease failed to respond to antistaphylococcal antibiotics. The mean time to correct diagnosis was longer than three months (15 weeks). The clinical features of the disease are highlighted and presented with a practical diagnostic approach to the child with subacute/chronic adenitis. New molecular diagnostic tools and emerging mycobacteria are discussed, including the first reports of Mycobacterium malmoense adenitis in Canada.

Integrated microRNA-mRNA-analysis of human monocyte derived macrophages upon Mycobacterium avium subsp. hominissuis infection

BACKGROUND

Many efforts have been made to understand basal mechanisms of mycobacterial infections. Macrophages are the first line of host immune defence to encounter and eradicate mycobacteria. Pathogenic species have evolved different mechanisms to evade host response, e.g. by influencing macrophage apoptotic pathways. However, the underlying molecular regulation is not fully understood. A new layer of eukaryotic regulation of gene expression is constituted by microRNAs. Therefore, we present a comprehensive study for identification of these key regulators and their targets in the context of host macrophage response to mycobacterial infections.

METHODOLOGY/PRINCIPAL FINDINGS

We performed microRNA as well as mRNA expression analysis of human monocyte derived macrophages infected with several Mycobacterium avium hominissuis strains by means of microarrays as well as quantitative reverse transcription PCR (qRT-PCR). The data revealed the ability of all strains to inhibit apoptosis by transcriptional regulation of BCL2 family members. Accordingly, at 48 h after infection macrophages infected with all M. avium strains showed significantly decreased caspase 3 and 7 activities compared to the controls. Expression of let-7e, miR-29a and miR-886-5p were increased in response to mycobacterial infection at 48 h. The integrated analysis of microRNA and mRNA expression as well as target prediction pointed out regulative networks identifying caspase 3 and 7 as potential targets of let-7e and miR-29a, respectively. Consecutive reporter assays verified the regulation of caspase 3 and 7 by these microRNAs.

CONCLUSIONS/SIGNIFICANCE

We show for the first time that mycobacterial infection of human macrophages causes a specific microRNA response. We furthermore outlined a regulatory network of potential interactions between microRNAs and mRNAs. This study provides a theoretical concept for unveiling how distinct mycobacteria could manipulate host cell response. In addition, functional relevance was confirmed by uncovering the control of major caspases 3 and 7 by let-7e and miR-29a, respectively.

Mycobacterial infections in Texas children: a 5-year case series

The epidemiology of nontuberculous mycobacterial infections is poorly understood, particularly in regions where tuberculosis (TB) is endemic. In 5 years, 75 children had nontuberculous mycobacterial disease (30 lymphadenopathy, 17 pulmonary, 17 soft tissue, and 11 bacteremia) and 30 had TB. Divergent antibiotic susceptibility profiles and the persistence of disease caused by TB emphasize the importance of microbiologic diagnosis for suspected mycobacterial disease.

Nontuberculous mycobacterial cervicofacial lymphadenitis in children from the multicenter, randomized, controlled trial in The Netherlands: relevance of polymorphisms in candidate host immunity genes

OBJECTIVE

The annual incidence of nontuberculous mycobacterial (NTM) cervicofacial lymphadenitis in otherwise healthy children is unexpectedly high (8 per million). It mostly arises as localized cervicofacial lymphadenitis. Previous research has suggested environmental risk factors for oral exposure to NTM and a temporal association with eruption of teeth. We studied 22 polymorphisms in relevant candidate genes, some related to periodontitis, in children with NTM lymphadenitis. We also tested for the most common mutation in IFNGR1.

METHODS

We analyzed DNA from 81 Dutch children with NTM from a nationwide surveillance study and 215 community controls for 22 polymorphisms in CD209, IL1B, IL8, IL10, IL12B, IL12RB1, IL18, PTX3, TLR4, TNF, VDR and SLC11A1 by MassArray platform (Sequenom) and CONTING. We screened for 818del4 in IFNGR1 by PCR and VspI restriction enzyme cleavage.

RESULTS

We found a positive association between NTM lymphadenitis and +3953TT in IL1B (OR 2.9; 95%-CI: 1.2-7.2). Furthermore, our results showed that -592C/A heterozygosity in IL10 is linked to protection from disease (OR 0.54; 95%-CI: 0.3-0.95), but that other polymorphisms were unrelated to localized NTM disease. However, these associations were not robust to Bonferroni's correction for multiple testing. None of the children carried the IFNGR1 818del4 mutation.

CONCLUSIONS

Dominance of environmental factors over genetic ones and insufficient sample size might explain the fragility of this study's results. Nevertheless, the association between NTM lymphadenitis and 3953C>T, a polymorphism previously linked to periodontitis, supports our hypothesis that oral exposure to mycobacteria during eruption of teeth plays a role in the etiology of cervical NTM lymphadenitis.

Differential diagnosis of cervical mycobacterial lymphadenitis in children

BACKGROUND AND AIMS

The differential diagnosis between tuberculosis (TB) and lymphadenitis caused by nontuberculous mycobacteria (NTM) in children is often based on epidemiologic and clinical data. The aim of this study was to identify epidemiologic and clinical variables associated with TB lymphadenitis in children attending 2 TB out-patient clinics in northern Italy during a 10-year period.

PATIENTS AND METHODS

All children less than 16 years of age attending the study sites suspected of mycobacterial disease from 1999 through 2008 were included in the analysis. Logistic regression was used to evaluate the variables independently associated with TB lymphadenitis.

RESULTS

From 299 children diagnosed with mycobacterial disease 121 children (40%) had a clinical diagnosis of cervical mycobacterial lymphadenitis: 38 TB (31%) and 83 NTM lymphadenitis (69%) cases. Increasing age (OR, 1.29; 95% CI, 1.02-1.69; P = 0.04), being foreign born (OR, 11.60; 95% CI, 1.37-114.20; P = 0.02), and having an abnormal chest radiograph (OR, 18.32; 95% CI, 2.37-201.68; P = 0.008) were independently associated with TB lymphadenitis. In the selected model, a 5-year-old foreign born child with cervical lymphadenitis and abnormal findings on chest radiograph has an estimated 0.90 probability of having TB disease. On the other hand, an Italy born child of the same age with cervical lymphadenitis and normal chest radiograph has a 0.04 probability of having TB.

CONCLUSION

Epidemiologic and clinical data are useful tools in the differential diagnosis between TB and NTM lymphadenitis when etiologic diagnosis is not available.

Nontuberculous mycobacterial infection in children: a prospective national study

BACKGROUND

The epidemiology and management of nontuberculous mycobacterial (NTM) infection in Australian children is unknown.

METHODS

From July 2004 to June 2007, clinicians identified children with NTM infection as part of a nationwide active surveillance network. Following notification, detailed data were collected.

RESULTS

From 192 reports, data were received on 153 cases (response rate: 79.7%). Of these, 102 met inclusion criteria. The median age was 2.9 years. Predisposing conditions were infrequent and included chronic respiratory disease (n = 12) and immunosuppression (n = 6). Lymphadenitis was the most frequent presentation (n = 68) with pulmonary and disseminated disease infrequent (n = 14 and 3, respectively). NTM was isolated in 68 cases with Mycobacterium avium-intracellulare complex most frequently isolated (33/68; 48.5%). Surgery was performed in 78 cases and 42 children were treated with antimycobacterial therapy. Twenty-five subjects received surgery and antimycobacterial therapy. Follow-up data were available for 77 children with recurrence observed in 18 cases. Complete excision was associated with a higher rate of treatment success when compared with all other therapies (OR: 9.48 [95% CI: 2.00-44.97], P = 0.001). Mycobacterium lentiflavum infection accounted for 4.4% of culture confirmed cases and had a lower rate of treatment success than other species (0% vs. 78.2%; P = 0.016).

CONCLUSIONS

The incidence of NTM infection in Australian children is 0.84 of 100,000 (95% CI: 0.68-1.02). Infection occurs most often in young children without predisposing conditions. Despite therapy, there was recurrence in 23.4% of cases.

Incidence rate of nontuberculous mycobacterial disease in immunocompetent children: a prospective nationwide surveillance study in Germany

An increasing incidence in disease caused by nontuberculous mycobacteria is being reported. We investigated the burden of disease in immunocompetent German children in a prospective nationwide study from April 2003 to September 2005. Ninety-seven percent of children presented with lymphadenitis; median age was 2.5 years. Using the capture-recapture method, we estimated a cumulative incidence rate of 3.1/100000 children.

Intrathoracic lymphadenitis caused by Mycobacterium avium and Mycobacterium tuberculosis in an immunocompetent child

By means of a DNA probe assay (INNO-LiPA) we identified 2 different mycobacterial strains (Mycobacterium avium and Mycobacterium tuberculosis complex) from a mediastinal lymph node biopsy obtained from an apparently immunocompetent 7.5-year-old girl, whereas culture grew only M. avium. Clinicians should be aware of the possible occurrence of mixed infection involving both nontuberculous mycobacteria and M. tuberculosis.

Proposed management of childhood tuberculosis in low-incidence countries

The incidence of childhood tuberculosis continues to decline in central Europe, but due to migration from high incidence countries paediatricians will still be confronted with it. The management of childhood tuberculosis in low-incidence, high-income countries differs from most high-incidence countries. The primary measures for preventing the transmission of tuberculosis to children are the detection of adult source cases, detection of latent TB infection (LTBI) in children by history, tuberculin skin testing and, if necessary and recommended, interferon-gamma release assays. Children with LTBI should receive preventive therapy. The inclusion of tuberculosis in the differential diagnosis of unclear pulmonary and extrapulmonary disease remains important, and tuberculosis has to be managed according to international standards.

Lymphadenitis in children is caused by Mycobacterium avium hominissuis and not related to 'bird tuberculosis'

Mycobacterium avium is the most commonly encountered mycobacterium species among non-Mycobacterium tuberculosis complex (nontuberculous mycobacteria) isolates worldwide and frequently causes lymphadenitis in children. During a multi-centre study in The Netherlands that was performed to determine the optimal treatment for mycobacterial lymphadenitis, concern was expressed in the media about the possible role of birds as sources of these M. avium infections, referred to as ‘bird tuberculosis.’ To examine the involvement of birds in mycobacterial lymphadenitis, 34 M. avium isolates from lymphadenitis cases were subjected to IS1245 restriction fragment length polymorphism (RFLP) typing. This genotyping method enables the distinction of the subspecies M. avium subsp. hominissuis and the ‘bird-type’ M. avium spp. avium. Highly variable RFLP patterns were found among the lymphadenitis M. avium isolates, and all belonged to the M. avium hominissuis subspecies. A relation to pet birds in the etiology of mycobacterial lymphadenitis could not be established, and the source of the infections may be environmental.

Broncholithiasis in an immune compromised boy with disseminated Mycobacterium kansasii

A case of broncholithiasis in a child is reported. To our knowledge, it has not been reported in children. Broncholithiasis is a condition in which a peribronchial calcified lymph node erodes into or distorts an adjacent bronchus. Symptoms of broncholithiasis include cough, recurrent episodes of fever, haemoptysis, and purulent sputum. The most common cause of broncholithiasis is Mycobacterium tuberculosis (M. tuberculosis). Here we describe a 14-year-old boy known to have disseminated Mycobacterium kansasii (M. kansasii) infection associated with hypoplastic myelodysplastic syndrome (MDS). He was presented with cough and fever. Computed tomography (CT) and bronchoscopy revealed a large calcified mass eroding in the right main bronchus. While surgical therapy was considered, haemoptysis developed and his condition deteriorated. Bone marrow puncture revealed acute myeloid leukemic transformation of the MDS. Curation was no longer possible. Post mortem examination revealed a large bronchiolith, evolving from a calcified lymph node.

Interferon- Release Assays Improve the Diagnosis of Tuberculosis and Nontuberculous Mycobacterial Disease in Children in a Country with a Low Incidence of Tuberculosis

BACKGROUND

Diagnosis of childhood tuberculosis (TB) is challenging. The widely used tuberculin skin test (TST) may produce -positive results because of cross-reactivity with nontuberculous mycobacteria or bacille Calmette-Guerin vaccination, resulting in unnecessary treatment. Two recently developed interferon- gamma release assays (IGRAs) show good diagnostic accuracy for active TB in adults; pediatric data are limited, particularly in areas with a low incidence of TB. We assessed the diagnostic accuracy of IGRAs for TB in children in an area with a low incidence of TB.

METHODS

In a hospital-based study, the diagnostic accuracy of the TST and 2 IGRAs (T SPOT-TB [T-SPOT; Oxford Immunotec] and QuantiFERON-TB Gold In-Tube [QFT-IT; Cellestis]) were assessed in a cohort of 73 children (median age, 39 months); 28 children with bacteriologically confirmed TB were compared with children without TB (23 with bacteriologically confirmed nontuberculous mycobacterial lymphadenitis and 22 with other nonmycobacterial respiratory tract infections).

RESULTS

The specificity for TB of QFT-IT was 100% (95% confidence interval [CI], 91%-100%), and the specificity of T-SPOT was 98% (95% CI, 87%-100%), both of which were considerably higher than the specificity of TST (58%; 95% CI, 42%-73%). The specificity of the TST was 10.5% (95% CI, 1%-33%) in children with nontuberculous mycobacterial lymphadenitis and was 100% (95% CI, 83%-100%) in children with other nonmycobacterial respiratory tract infections. The sensitivity of both QFT-IT and T-SPOT was 93% (95% CI, 77%-99%), and the sensitivity of the TST was 100% (95% CI, 88%-100%). Agreement between the IGRAs was 95.6% ( kappa =0.91); 6.8% of the IGRAs showed indeterminate results.

CONCLUSIONS

Both IGRAs showed high diagnostic value in bacteriologically confirmed childhood TB. Their advantage in this study, when performed in addition to the TST, was the ability to distinguish -positive TST results caused by nontuberculous mycobacterial disease, thereby reducing overdiagnosis of TB and guiding clinical management.

Adenitis por micobacterias no tuberculosas

OBJECTIVE

To study the clinical features, epidemiology and outcome of nontuberculous mycobacterial lymphadenitis (NTML).

METHODS

A retrospective study was performed on 54 patients under 14 years old diagnosed with atypical mycobacterial lymphadenitis between 1987 and 2004. Inclusion criteria were: (i) positive polymerase chain reaction (PCR) test or culture; (ii) positive sensitin skin test 6 mm above Mantoux; (iii) histopathologic features compatible with mycobacterial infection and/or positive direct smear for acid-fast bacilli, Mantoux reaction less than 15 mm, a normal chest radiograph, absence of exposure to an adult with tuberculosis, negative Mantoux test reactions in family members, and exclusion of other causes of granulomatous adenitis.

RESULTS

Fifty-four patients were included in the study. The number of NTML cases increased notably from 1996, coinciding with a decrease in cases of tuberculous adenitis. The mean age was 35 months (range: 14 months-6 years). Submandibular nodes were involved in 22 of 63 cases of adenitis (34.9%) and cervical nodes were involved in 21 (33.3%). In 8/42 patients (19%) the tuberculin skin test was larger than 10 mm. Cultures were positive in 52.9% of the cases (18/34) and PCR in 53.3% (8/15). The most frequently isolated mycobacteria was Mycobacterium avium (61%). Therapy failed in 8/21 patients receiving antibiotics (38%), in 10/13 patients with drainage alone (77%) and in none of the patients who underwent surgery (8/8).

CONCLUSIONS

Nontuberculous mycobacterial adenitis has become more frequent in our hospital since 1996. Cultures do not always allow isolation of mycobacteria and the Mantoux test frequently yields false positive results, thus hampering diagnosis. The most effective treatment was surgical excision. Nevertheless, when the surgical approach is difficult or there is postoperative recurrence, pharmacological treatment can be useful.

Isolation of non-tuberculous mycobacteria in children investigated for pulmonary tuberculosis

Objective

To evaluate the frequency and clinical significance of non-tuberculous mycobacteria (NTM) isolates among children investigated for pulmonary tuberculosis in a rural South African community.

Methods

Children were investigated for pulmonary tuberculosis as part of a tuberculosis vaccine surveillance program (2001–2005). The clinical features of children in whom NTM were isolated, from induced sputum or gastric lavage, were compared to those with culture-proven M. tuberculosis.

Results

Mycobacterial culture demonstrated 114 NTM isolates from 109 of the 1,732 children investigated, a crude yield of 6% (95% CI 5–7). The comparative yield of positive NTM cultures from gastric lavage was 40% (95% CI 31–50), compared to 67% (95% CI 58–76) from induced sputum. 95% of children with NTM isolates were symptomatic. Two children were HIV-infected. By contrast, M. tuberculosis was isolated in 187 children, a crude yield of 11% (95% CI 9–12). Compared to those with culture-proven M. tuberculosis, children with NTM isolates were less likely to demonstrate acid-fast bacilli on direct smear microscopy (OR 0.19; 95% 0.0–0.76). Children with NTM were older (p<0.0001), and more likely to demonstrate constitutional symptoms (p = 0.001), including fever (p = 0.003) and loss of weight or failure to gain weight (p = 0.04), but less likely to demonstrate a strongly positive tuberculin skin test (p<0.0001) or radiological features consistent with pulmonary tuberculosis (p = 0.04).

Discussion

NTM were isolated in 6% of all children investigated for pulmonary tuberculosis and in more than one third of those with a positive mycobacterial culture. NTM may complicate the diagnosis of PTB in regions that lack capacity for mycobacterial species identification. The association of NTM isolates with constitutional symptoms suggestive of host recognition requires further investigation.

Granulomatous lesions in lymph nodes of slaughter pigs bacteriologically negative for Mycobacterium avium subsp. avium and positive for Rhodococcus equi

The prevalence of granulomatous lesions in lymph nodes of pigs was studied. From January till August 2004 in two slaughterhouses in The Netherlands 2,116,536 pigs were examined for the presence of granulomatous lesions in the sub-maxillary lymph nodes. In 15,900 (0.75%) of these pigs, lesions could be detected. Nine farms with the highest incidence of lesions were selected for a more detailed pathological and bacteriological examination. On these farms, the prevalence of lesions in sub-maxillary lymph nodes ranged from 2.3 to 5.7% with a mean of 3.0%. From 1276 pigs that were sampled, 98 (7.7%) displayed granulomatous lesions in the sub-maxillary lymph nodes and one (0.1%) pig showed lesions in its mesenteric lymph node. Mycobacterium avium subsp. avium (MAA) could not be isolated from the lymph nodes of the 99 pigs with lesions and from a selection of lymph nodes (n=61) of pigs without lesions. Rhodococcus equi was isolated from 44 out of 98 (44.9%) of the sub-maxillary lymph nodes with granulomatous lesions and from two mesenteric lymph nodes without lesions. A comparison of former studies and the current results indicate that the prevalence of MAA infections in slaughter pigs has strongly decreased over the last decade, whereas R. equi is highly prevalent. The high incidence of granulomatous lesions associated with the bacteriological presence of R. equi could be considered as a serious cause of misdiagnosis of MAA infections in cases where meat inspection is carried out by inspection for granulomatous changes of lymph nodes only.

Tuberculin skin testing is useful in the screening for nontuberculous mycobacterial cervicofacial lymphadenitis in children

BACKGROUND

We evaluated the diagnostic usefulness of tuberculin skin testing in the screening for nontuberculous mycobacterial (NTM) infection in children.

METHODS

We enrolled 180 children who had chronic cervicofacial lymphadenitis in our study. Skin testing was done using antigens of Mycobacterium tuberculosis, Mycobacterium avium, Mycobacterium kansasii, and Mycobacterium scrophulaceum. The reference standard for NTM infection was a positive culture result, identification by PCR, or both. Receiver operating characteristic analysis was used to identify the optimal cutoff point in skin induration for the detection of NTM infection. Accuracy of the mycobacterial skin tests was quantified using sensitivity and specificity rates and positive and negative predictive values at the optimal skin induration cutoff.

RESULTS

A total of 112 NTM infections were identified, of which 83 were caused by M. avium, 21 by Mycobacterium haemophilum, and 8 by other NTM species. At the optimal cutoff for a positive test (5 mm), tuberculin skin testing had a sensitivity and specificity of 70% and 98%, respectively, and a positive predictive value and a negative predictive value of 98% and 64%, respectively, compared with a sensitivity and a specificity of 93% and 97%, respectively; M. avium sensitin, the best-performing skin test, had positive and negative predictive values of 98% and 90%, respectively.

CONCLUSION

Tuberculin skin testing could be valuable as a first step in the diagnostic analysis of cervicofacial lymphadenitis in children without a history of TB exposure or bacille Calmette-Guérin vaccination.

Mycobacterium abscessus Cervical Lymphadenitis: An Immunocompetent Child

Nontuberculous mycobacterium (NTM) is one of the well-known causes of cervicofacial lymphadenopathy in children under 5 years of age. Children often present with a painless cervical mass that fails to respond to conventional antibiotics. They are often referred under the suspicion of a neoplasm or bacterial adenitis rather than NTM cervical lymphadenitis. The lack of systemic symptoms, modest or negative purified protein derivative test and absence of exposure to active tuberculosis are characteristics of NTM lymphadenitis. The diagnosis usually requires the isolation of pathogen or pathologic proof. Complete excision is the choice of treatment by the majority of authors in the literature. This not only enables rapid diagnosis but ensures the lowest recurrence rate. Medical management is sometimes successful when complete resection is impossible or refused. To our knowledge, the incidence of NTM cervical lymphadenitis in children is increasing throughout the world. However, such reports of children in Taiwan is lacking. Clinicians should suspect a possible nontuberculous mycobacterial infection when a cervical lump is found in a child.

Human host genetic factors in nontuberculous mycobacterial infection: lessons from single gene disorders affecting innate and adaptive immunity and lessons from molecular defects in interferon-gamma-dependent signaling

Mendelian defects in interferon-gamma (IFN-gamma) signaling most commonly lead to infection with nontuberculous mycobacteria. Mutations have been identified in the genes encoding IFN-gamma-receptor-1, IFN-gamma-receptor-2 and Stat-1. Partial and complete deficiencies in signaling are found, leading to parallel clinical, pathological, and cellular phenotypes. These rare defects have led to better molecular and mechanistic understanding of the role of IFN-gamma in the human immune system.

Vaccination strategies to prevent tuberculosis in the new millennium: from BCG to new vaccine candidates

Current global control efforts targeting tuberculosis (TB) include the treatment of latent TB infection, case detection and treatment with directly observed therapy short-course (DOTS), and BCG (bacille Calmette-Guérin) vaccination. However, BCG has been found to decrease only childhood TB morbidity and mortality but has a very limited effect in the transmission dynamics of the infection. These limitations of BCG are the driving force for the development of new TB vaccines. New TB vaccine candidates have entered clinical evaluation and many more are in the pipeline to undergo clinical testing. New vaccine candidates may offer better protection than that afforded by currently available BCG vaccines. Furthermore, combined vaccination schedules against TB seem to be a promising strategy in the new millennium.

Disease caused by non-tuberculous mycobacteria in a university hospital in Taiwan, 1997-2003

From January 1997 to December 2003, all patients with non-tuberculous mycobacteria (NTM) isolation who were treated at a university hospital in Taiwan were evaluated. Among the 2650 NTM isolates, 1225 (46.2%) were from 412 patients with clinically significant diseases. The annual incidence (per 100000 patients) of disease caused by NTM was 8.96 in 1997, 21.53 in 2002, and 16.55 in 2003. The major types of infections caused by NTM included isolated pulmonary infection and pleurisy (59.5%), skin/soft-tissue infections and osteomyelitis (13.8%), and disseminated diseases (13.3%). The two most common groups of organisms involved were rapidly growing mycobacteria (RGM) (41.4%) and Mycobacterium avium complex (MAC) (39%). The most common organism involved in isolated pulmonary infection and pleurisy was MAC (44.1%). RGM predominated in keratitis (94%), skin/soft-tissue infections and osteomyelitis (43.9%), and lymphadenitis (66.7%). This retrospective 7-year study demonstrated an increase in the incidence of NTM disease in a university hospital.