Primary epiphyseal or apophyseal subacute osteomyelitis in the pediatric population: a report of fourteen cases and a systematic review of the literature

Pediatric Osteoarticular Kingella kingae Infections of the Hand and Wrist: A Retrospective Study

Our understanding of pediatric osteoarticular infections (OAIs) has improved significantly in recent decades. Kingella kingae is now recognized as the most common pathogen responsible for OAIs in pediatric populations younger than 4 years old. Research has provided a better understanding of the specific types, clinical characteristics, biological repercussions, and functional outcomes of these infections. Hands and wrists are rarely infected, with few reports available in the literature. The present study aimed to examine this specific condition in a large patient cohort, explore the implications for each anatomical area using magnetic resonance imaging (MRI), and critically evaluate the evolution of therapeutic management.

Fungal Osteomyelitis of the Proximal Tibial Epiphysis and Septic Arthritis Secondary to an Open Wound: A Case Report

CASE

A 9-year-old boy presented with a painful, swollen knee. He had a wound on the knee 2 months ago after a fall in contaminated water. At another hospital, this was treated with debridement twice, and the patient received several antibiotics. Imaging showed septic arthritis and epiphyseal osteomyelitis involving the proximal medial tibia. Surgical debridement and joint washout were performed. Fungal cultures grew Scedosporium boydii. Antifungal treatment with voriconazole was given. At a 5-year follow-up, we noticed favorable outcomes without any complications.

CONCLUSIONS

Fungal osteomyelitis because of direct inoculation should be considered a rare differential diagnosis while treating epiphyseal osteomyelitis.

Pediatric musculoskeletal infections

PURPOSE OF REVIEW

The aim of this article is to review the recent guidelines and literature regarding the diagnosis and the treatment of common pediatric musculoskeletal infections: septic arthritis, osteomyelitis, pyomyositis, and Lyme disease.

RECENT FINDINGS

In the last decade, a better understanding of the causative organisms of common bacterial infections, including Kingella , leads to prompt targeted antimicrobial coverage in all musculoskeletal infections. Prompt diagnosis and treatment continues to be the mainstay in the treatment of children with osteoarticular infections. Efforts to improve early detection have lead to improving rapid lab diagnostic testing; however, more advanced diagnostics such as arthrocentesis for septic arthritis and MRI for osteomyelitis and pyomyositis, remain the gold standard. Shorter and narrowed antibiotic courses, with appropriate transition to outpatient oral treatment provide effective infection clearance and reduction in complications of disease.

SUMMARY

Advances in diagnostics, including pathogen identification as well as imaging continues to improve our ability to diagnose and treat these infections, although still lack ability to provide definitive diagnosis without more invasive nor advanced techniques.

Transphyseal Hematogenous Osteomyelitis: An Epidemiological, Bacteriological, and Radiological Retrospective Cohort Analysis

Transphyseal hematogenous osteomyelitis (THO) is a serious condition that can affect the growing physis, yet it is insufficiently recognized in children. The aim of this study was to explore the prevalence and epidemiology of pediatric THO, and to discuss the underlying pathophysiology. All consecutive cases of acute and subacute osteomyelitis admitted to our institution over 17 years were retrospectively studied. Medical records were examined for patient characteristics, bacteriological etiology, and medical and surgical management. Magnetic resonance imaging was reviewed for all patients to identify those with transphyseal spread of infection. For positive cases, the surface area of the transphyseal lesion was estimated relative to the total physeal cross-sectional area. Fifty-four (25.7%) of the 210 patients admitted for acute or subacute osteomyelitis were diagnosed with THO. The study population’s ages ranged from 1 month to 14 years old (median age 5.8 years, interquartile range 1–167 months). Fourteen (25.9%) patients were younger than 18 months old; the remaining 40 (74.1%) had a mean age of 8.5 years old. The most common sites of THO were the distal tibia (29.1%), the proximal tibia (16.4%), and the distal fibula (14.5%). Transphyseal lesions were due to acute infection in 41 cases and to subacute osteomyelitis in 14 cases. The two most frequently identified pathogens were Staphylococcus aureus (49.1%) and Kingella kingae (20.0%). An average transphyseal lesion represented 8.9% of the total physeal surface, and lesions comprised more than 7% of the physeal cross-sectional area in 51% of cases. Our study revealed that pediatric THO was more frequent than commonly thought. Transphyseal lesions were frequently above this 7% cut-off, which is of paramount importance since subsequent growth is more likely to be disturbed when more than 7% of the physeal cross-sectional area is injured. THO also affected children older than 18 months, an age at which transphyseal arterial blood supply to the epiphysis is believed to have disconnected. This finding suggests another pathophysiological reason for the transphyseal diffusion of infection, a topic deserving further studies and greater understanding.

Imaging Osteomyelitis: An Update

BACKGROUND

 Hematogenous osteomyelitis has increased over the past quarter century in frequency, virulence, and degree of soft-tissue involvement, bringing about changes in clinical manifestations and management of the disease especially in children that should be reflected in the current imaging approach. Likewise, the global disease burden of diabetes has increased greatly in the same period, compounding the problem of ascertaining osteomyelitis in diabetic foot.

METHOD

 This article provides an updated overview of imaging findings in hematogenous and contiguous osteomyelitis based on the literature and our institutional experience, along with salient features of recent recommendations from expert groups on the diagnostic algorithms and reporting terminology.

RESULTS AND CONCLUSION

 Findings on radiography and especially magnetic resonance imaging (MRI) closely reflect pathophysiology in osteomyelitis, whereby the characteristic involvement of the metaphysis or metaphyseal-equivalents, the formation and subperiosteal extension of intramedullary pus collection, and the development of cloaca, sequestrum, and involucrum are all diagnostic clues. Non-enhancing foci within the medullary bone, the penumbra sign, intra- or extramedullary fat globules, and surrounding soft tissue inflammation or abscesses are among key MRI findings. Diabetic foot is a special condition with characteristic pathophysiologic and imaging features that suggest the likelihood of osteomyelitis and the main differential diagnostic consideration of acute on chronic neuropathic osteoarthropathy with or without osteomyelitis.

KEY POINTS

  · Imaging closely reflects pathophysiology in hematogenous osteomyelitis.. · Acute hematogenous osteomyelitis predominantly involves metaphyses and metaphyseal equivalent sites.. · MRI clues for hematogenous osteomyelitis include central marrow non-enhancement, intra- or extramedullary fat globules, and the "penumbra" sign.. · An increased fluid-sensitive MRI bone signal abutting a soft tissue ulcer, abscess, or sinus tract suggests a high probability of contact osteomyelitis..

CITATION FORMAT

· Aydingoz U, Imaging Osteomyelitis: An Update. Fortschr Röntgenstr 2023; DOI: 10.1055/a-1949-7641.

Surgical Management of an Osteomyelitis Associated Subchondral Bone Defect in the Pediatric Knee Based on Arthroscopy, “Ossoscopy” and Bone Grafting—A Case Report

Subchondral bone defects around the knee joint are uncommon in skeletally immature patients. These lesions require comprehensive management, especially if related to periarticular bacterial infections. While pediatric osteomyelitis typically affects the metaphysis of long bones, the epiphysis is also a potential site for pyogenic osteomyelitis. Long-term sequelae may include growth plate injury and articular cartilage degradation. Primary epiphyseal subacute osteomyelitis is an extremely rare condition, mainly affecting neonates or young infants, as the cartilage of the growth plate generally acts as a barrier for pathogens. Radiographically, the lesions may appear radiolucent or lytic and often demonstrate a substantial perilesional bone marrow edema in MRI studies, but do not primarily contact the articular surface. However, if diagnosis and treatment of epiphyseal infections are delayed or missed, abscess formation may spread into the knee joint and progress to septic arthritis. Approaching a distal femoral epiphyseal lesion or subsequent bone defect surgically may be limited anatomically by both the subchondral plate and articular cartilage on the distal side and the growth plate proximally. Of the few reported cases of epiphyseal osteomyelitis, most underwent non-operative treatment including antibiotic coverage, or (staged) aggressive surgical care involving open curettage, irrigation and bone grafting. We report a novel combination of arthroscopic techniques, namely “ossoscopy”, bone grafting and antibiotics, to approach a large lateral femoral epiphyseal lesion with knee involvement. In this case report, we present a 5-year old male patient with subacute posttraumatic knee pain and a significant bone defect of the lateral femoral epiphysis related to pyogenic osteomyelitis. The knee joint and periarticular bone lesion were both debrided and irrigated based on arthroscopic and ossoscopic techniques.The osseous lesion was filled with bone graft. The single-stage procedure proved to be a viable treatment to restore both the large subchondral bone defect and full knee function. Over a course of two years, no recurrent symptoms, infection or growth disturbances were observed in the individual.

Kingella kingae Osteoarticular Infections Approached through the Prism of the Pediatric Orthopedist

Nowadays, Kingella kingae (K. kingae) is considered as the main bacterial cause of osteoarticular infections (OAI) in children aged less than 48 months. Next to classical acute hematogenous osteomyelitis and septic arthritis, invasive K. kingae infections can also give rise to atypical osteoarticular infections, such as cellulitis, pyomyositis, bursitis, or tendon sheath infections. Clinically, K. kingae OAI are usually characterized by a mild clinical presentation and by a modest biologic inflammatory response to infection. Most of the time, children with skeletal system infections due to K. kingae would not require invasive surgical procedures, except maybe for excluding pyogenic germs' implication. In addition, K. kingae's OAI respond well even to short antibiotics treatments, and, therefore, the management of these infections requires only short hospitalization, and most of the patients can then be treated safely as outpatients.

Subacute osteomyelitis of the tibial diaphysis associated with Brodie's abscess: A rare case report of a four-year-old child

Introduction

Septic osteomyelitis is a hematogenous bacterial bone infection. The acute presentation is the most common; the subacute one is less frequent. The aim of our case report is to put forward the features of this uncommon presentation and to propose a therapeutic management.

Presentation of case

We report a rare case of subacute osteomyelitis associated with Brodie's abscess of the tibial diaphysis in a four-year-old child. The chief complaint was a pain in the left tibia evolving for five weeks. The radiological findings and the unusual location of this pathology suggested a malignant bone tumor. Thanks to imaging assessment and bone biopsy the diagnosis of subacute osteomyelitis associated with Brodie's abscess was made. Therefore, the child had antibiotic therapy and plaster immobilization to avoid pathological fracture. Pain relief and radiological improvement was obtained after 3 months of antibiotic treatment. At a two-year follow-up, the X-ray was normal.

Discussion

We report an uncommon case of subacute osteomyelitis which evolved to Brodie's abscess with diaphyseal location. The mainstream treatment is surgery combined with antibiotics. However, medical treatment alone can lead to recovery without sequelae.

Conclusion

Because of the atypical location and presentation of subacute osteomyelitis, the other differential diagnoses, especially malignant bone tumors have to be eliminated. In some cases, treatment may be based on antibiotics therapy alone.

•

The MRI findings can mimic a malignant bone tumor.

•

The importance of the biopsy for the diagnosis.

•

Antibiotic treatment without surgery is an alternative for the treatment of circumscribed Brodie’s abscess.

Clinical Practice Guideline by the Pediatric Infectious Diseases Society and the Infectious Diseases Society of America: 2021 Guideline on Diagnosis and Management of Acute Hematogenous Osteomyelitis in Pediatrics

This clinical practice guideline for the diagnosis and treatment of acute hematogenous osteomyelitis (AHO) in children was developed by a multidisciplinary panel representing Pediatric Infectious Diseases Society (PIDS) and the Infectious Diseases Society of America (IDSA). This guideline is intended for use by healthcare professionals who care for children with AHO, including specialists in pediatric infectious diseases, orthopedics, emergency care physicians, hospitalists, and any clinicians and healthcare providers caring for these patients. The panel's recommendations for the diagnosis and treatment of AHO are based upon evidence derived from topic-specific systematic literature reviews. Summarized below are the recommendations for the diagnosis and treatment of AHO in children. The panel followed a systematic process used in the development of other IDSA and PIDS clinical practice guidelines, which included a standardized methodology for rating the certainty of the evidence and strength of recommendation using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach. A detailed description of background, methods, evidence summary and rationale that support each recommendation, and knowledge gaps can be found online in the full text.

Review highlights the latest research in Kingella kingae and stresses that molecular tests are required for diagnosis

AIM

The aim of this study was to provide an update on paediatric Kingella kingae infections.

METHODS

We used the PubMed database to identify studies published in English, French and Spanish up to 15 November 2020.

RESULTS

Kingella kingae colonised the oropharynx after the age of 6 months, and the mucosal surface was the portal of entry of the organism to the bloodstream and the source of child-to-child spread. Attending day care centres was associated with increased carriage rate and transmission and disease outbreaks were detected in day care facilities. Skeletal system infections were usually characterised by mild symptoms and moderately elevated inflammation markers, requiring a high clinical suspicion index. The organism was difficult to recover in cultures and molecular tests significantly improve its detection. Kingella kingae was generally susceptible to beta-lactam antibiotics, and skeletal diseases and bacteraemia responded to antimicrobial, leaving no long-term sequelae. However, patients with endocarditis frequently experienced life-threatening complications and the case fatality rate exceeded 10%.

CONCLUSION

Kingella kingae was the prime aetiology of skeletal system infections in children aged 6-48 months. Paediatricians should be aware of the peculiar features of this infection and the need to use molecular tests for diagnosis.

Osteomyelitis in an Unusual Location With an Atypical Presentation: A Case Report and Review of the Literature of Scapular Osteomyelitis in Pediatric Patients

ABSTRACT

Bacterial osteomyelitis of the scapula is rare in pediatric patients. When it occurs, it usually affects young infants and patients often exhibit fever and functional limitation of the extremity. We present a case of a 12-year-old boy with subacute bacterial scapular osteomyelitis and a normal physical examination. The patient was briefly treated with intravenous antibiotics and then transitioned to oral antibiotics to complete a 4-week course for methicillin-sensitive Staphylococcus aureus osteomyelitis.

[Pediatric bone marrow alterations]

The age-dependent development of the bone marrow follows a constant pattern and has an impact on the localization and morphology of various bone marrow processes. Physiological, reactive and benign bone marrow alterations must be differentiated from inflammatory or malignant infiltrations. In many cases, a specific age distribution pattern and typical morphological characteristics in magnetic resonance imaging (MRI) enable a diagnostic classification. The only adequate imaging modality that can provide information about the bone marrow composition is MRI.

Zn-contained mussel-inspired film on Mg alloy for inhibiting bacterial infection and promoting bone regeneration

Infection and insufficient osteointegration are the main causes of orthopedic implant failure. Furthermore, activating favorable inflammation response is vital to the fast osteointegration of implants. Therefore, endowing the implants with multifunctions (antibacterial, anti-inflammation, and pro-osteointegration) is a promising strategy to improve the performance of orthopedic implants. In this study, a Zn-contained polydopamine (PDA) film was fabricated on AZ31 alloy. The film possessed a stable Zn ion release in 14 days. The results of electrochemical analysis implied the favorable corrosion protection of the film, and thus, leading to a suitable hemolysis ratio (below 1%). The in vitro antibacterial assessment revealed that the film exhibited excellent resistance against Staphylococcus aureus (nearly 100%), which can be ascribed to the release of Zn ions. The cell-culture evaluation revealed that the extract of Zn-contained PDA-coated sample can activate RAW264.7 polarization to an anti-inflammatory phenotype, as well as enhance the osteogenic differentiation ability of MC3T3-E1. Additionally, the femoral osteomyelitis model indicated that the as-prepared film had a high antibacterial capability at early stage of the implantation, and showed better osteogenesis and osteointegration after 8 weeks of implantation. With favorable antibacterial, anti-inflammation, and pro-osteogenesis abilities, the novel designed Zn-contained PDA film is promising to be used in Mg-based orthopedic implants.

Full Femoral Osteomyelitis Caused by Fusobacterium nucleatum in an Immunocompetent Adult: A Case Report

CASE

We present a 46-year-old man who developed a full femoral osteomyelitis caused by Fusobacterium nucleatum. The subtle presentation of the infection and the late onset of appropriate antibiotic treatment caused a devastating bone quality of the full femur.

CONCLUSIONS

A successful outcome was obtained with surgical debridement, antibiotics, and return to weight bearing guided by a laboratory and radiographic scale specially designed to avoid pathologic fractures toward his full functional recovery.

Solitary long-bone epiphyseal lesions in children: radiologic-pathological correlation and epidemiology

BACKGROUND

Solitary epiphyseal lesions are rare and present with nonspecific imaging features. Knowledge regarding etiologies of pediatric epiphyseal lesions is limited to small studies.

OBJECTIVE

The purpose of this study was to determine the relative incidence of pathologies affecting the pediatric epiphysis based on biopsy-proven cases with imaging.

MATERIALS AND METHODS

We conducted a retrospective review of imaging studies including the terms "biopsy" or "resection" and entities known to affect the epiphysis and cross-referenced these with pathology reports, recording the relevant clinical data. Two radiologists performed comprehensive imaging review and recorded relevant features.

RESULTS

Forty-nine children and adolescents met inclusion criteria. The long-bone epiphyseal lesion etiologies included chondroblastoma (n=22, 45%), nonspecific nonmalignant pathology (n=11, 22%), osteomyelitis (n=9, 18%), lymphoma (n=2, 4%) and 1 case of each of aneurysmal bone cyst, chondrosarcoma, enchondroma, hemangioendothelioma, and non-Langerhans cell histiocytosis. Median age was 13.1 years old (range 1.5-18.6 years). We performed comparative analysis of the two most common lesions in our series, chondroblastoma and osteomyelitis. Chondroblastoma was significantly more likely to be peripherally located (94% vs. 33%, P=0.002) and to demonstrate a discrete T1-weighted hypointense rim (94% vs. 33%, P=0.002); there were no significant differences in enhancement or intrinsic signal properties. Children with chondroblastoma were older (15.1 years vs. 7.3 years, P=0.001), and chondroblastoma lesions were significantly larger, with mean maximum lesion diameter of 25 mm (interquartile range [IQR] 20-30) vs. 12 mm (IQR 11-18) (P=0.001) and lesion volumes of 4.4 mL (IQR 2.4-7.9) vs. 0.4 mL (IQR 0.2-1.4) (P=0.01).

CONCLUSION

This study reports the relative frequency of pathology of pediatric solitary epiphyseal lesions and describes several features that might assist in differentiating between chondroblastoma and osteomyelitis.

Primary Epiphyseal Osteomyelitis (PEO) in 18 Children: A Rare Entity With Atypical Features

OBJECTIVES

The purpose of this study is to discuss the natural history and management of primary epiphyseal osteomyelitis (PEO), to differentiate clinico-radiologic features of PEO caused by Mycobacterium and other organisms, and to discuss their intermediate-term outcomes.

METHODS

Between 2006 and 2017, 18 patients of PEO were managed at our center. Blood investigations, x-rays, and magnetic resonance imaging of affected part were carried out. Surgical drainage of lesions was done to retrieve infective fluid and tissue for examination. Antibiotics were administered for 1 year in Mycobacterial PEO and for 6 weeks in bacterial PEO. Average follow-up of patients was 5.5 years (range, 2 to 11 y).

RESULTS

Boys were more commonly affected (11/18). Distal femur was the most common site involved (12/18). Eleven patients had Mycobacterium tuberculosis as the causative organism, 6 were positive for Staphylococcus aureus, and 1 for Brucella. Swelling and limp were predominant in patients with Tubercular PEO, whereas pain was more common in bacterial PEO. Nine of 11 patients with Tubercular PEO had penetration into the joint, whereas none in bacterial PEO. All patients recovered completely without residual movement restriction or growth alteration. On follow-up magnetic resonance imaging, 4 patients with Tubercular PEO had thinning of articular cartilage.

CONCLUSION

High index of suspicion is required for early diagnosis of PEO. It is important to differentiate Tubercular from other bacterial PEO as it has more subtle symptoms and poor prognosis if left untreated. Aggressive surgical treatment followed by antibiotic therapy of appropriate duration is required to avoid complications related to joint destruction. To our knowledge, this is the largest reported series with longest follow-up.

Systematic Review of Kingella kingae Musculoskeletal Infection in Children: Epidemiology, Impact and Management Strategies

Kingella kingae, a pathogen often responsible for musculoskeletal infections in children is the most common cause of septic arthritis and osteomyelitis in children 6 to 36 months of age. The aim of this study was to perform a systematic review of previous studies to determine the proportion of K. kingae in bacteriologically proven musculoskeletal infections among the pediatric population. A secondary objective was to describe the diagnostic strategies and outcome of patients with musculoskeletal infections caused by K. kingae. A systematic review was conducted to identify publications that report on musculoskeletal infections caused by K. kingae in the pediatric population (patients 0 to <18 years old with microbiologic culture and/or polymerase chain reaction (PCR) confirmation of K. kingae and a description of the musculoskeletal infection involved). Of 144 studies included in this review, we sought to determine the proportion of K. kingae pediatric musculoskeletal infections. A total of 711 (30.8%) out of 2308 pediatric cases with culture and/or PCR proven musculoskeletal infections had K. kingae successfully identified from twenty-nine studies. Of the 1070 patients who were aged less than 48 months, K. kingae was the organism identified in 47.6% of infections. We found the average age from the collated studies to be 17.73 months. Of 520 pediatric musculoskeletal patients in which K. kingae infections were identified and where the studies reported the sites of infection, a large proportion of cases (65%) were joint infections. This was followed by 18.4% osteoarticular infection (concomitant bone and joint involvement), with isolated bone and spine at 11.9% and 3.5%, respectively. Twenty-one papers reported clinical and laboratory findings in children with confirmed K. kingae infection. The median temperature reported at admission was 37.9°C and mean was 38.2°C. Fourteen studies reported on impact and treatment, with the majority of children experiencing good clinical outcome and function following antibiotic treatment with no serious orthopaedic sequelae.

Subacute Osteomyelitis of the Pediatric Talus: A First Report of Brodie's Abscess from Morganella morganii

Brodie's abscess is a subacute form of osteomyelitis which generally occurs in the metaphysis of the femur and tibia in the pediatric population. Pathogens are most commonly Gram-positive bacteria, notably Staphylococcus and Streptococcus. In this article, we describe a young pediatric patient presenting with subacute ankle pain with a subsequent diagnosis of Brodie's abscess of the talus secondary to Morganella morganii. We review the presentation, diagnosis, and treatment of this unique patient. To our knowledge, this is the first report of Morganella morganii as a cause of Brodie's abscess.

A New Highly Sensitive and Specific Real-Time PCR Assay Targeting the Malate Dehydrogenase Gene of Kingella kingae and Application to 201 Pediatric Clinical Specimens

Kingella kingae is a significant pediatric pathogen responsible for bone and joint infections, occult bacteremia, and endocarditis in early childhood. Past efforts to detect this bacterium using culture and broad-range 16S rRNA gene PCR assays from clinical specimens have proven unsatisfactory; therefore, by the late 2000s, these were gradually phased out to explore the benefits of specific real-time PCR tests targeting the groEL gene and the RTX locus of K. kingae However, recent studies showed that real-time PCR (RT-PCR) assays targeting the Kingella sp. RTX locus that are currently available for the diagnosis of K. kingae infection lack specificity because they could not distinguish between K. kingae and the recently described Kingella negevensis species. Furthermore, in silico analysis of the groEL gene from a large collection of 45 K. kingae strains showed that primers and probes from K. kingaegroEL-based RT-PCR assays display a few mismatches with K. kingae groEL variations that may result in decreased detection sensitivity, especially in paucibacillary clinical specimens. In order to provide an alternative to groEL- and RTX-targeting RT-PCR assays that may suffer from suboptimal specificity and sensitivity, a K. kingae-specific RT-PCR assay targeting the malate dehydrogenase (mdh) gene was developed for predicting no mismatch between primers and probe and 18 variants of the K. kingae mdh gene from 20 distinct sequence types of K. kingae This novel K. kingae-specific RT-PCR assay demonstrated high specificity and sensitivity and was successfully used to diagnose K. kingae infections and carriage in 104 clinical specimens from children between 7 months and 7 years old.

Paediatric Bone and Joint Infections in French Guiana: A 6 Year Retrospective Review

The epidemiology of paediatric bone and joint infections from South America is poorly known. We herein report a retrospective study conducted in whole French Guiana from January 2010 to December 2015. Medical charts of 55 previously healthy children were analysed, identifying 27 with osteomyelitis, 22 with septic arthritis and 6 with multifocal infections and/or osteoarthritis. The male:female ratio was 2.2:1, and the mean age was 7.5 years. Eighty percent children were ≥36 months old who had predominantly osteomyelitis related to methicillin-susceptible Staphylococcus aureus (p < 0.05) in the course of neglected skin infections. Five children presented with multi-systemic infections resulting in one fatality, mainly caused by S. aureus producing Panton-Valentine leucocidin (p < 0.01). In contrast, children aged 6-36 months had more likely culture-negative infections (p < 0.05), septic arthritis and mild clinical and biological features. Further prospective studies are required to better guide rational diagnostic and therapeutic strategies.

Brodie abscess of the femoral capital epiphysis in a 2-year-old child caused by Kingella kingae

We report the case of a Brodie abscess of the femoral capital epiphysis from which Kingella kingae was isolated. This is to the best of our knowledge the first report of a Brodie abscess of the femoral capital epiphysis from which K. kingae was isolated.

Primary subacute epiphyseal osteomyelitis caused by Mycobacterium species in young children: a modern diagnostic approach

Primary epiphyseal subacute osteomyelitis (PESAO) caused by Mycobacterium species in young children is poorly recognized. We aimed to define the spectrum of this uncommon condition and to propose a novel diagnostic approach. We performed a systematic review of the literature on the PubMed website by selecting all reports of isolated infantile PESAO caused by Mycobacterium species since 1975. We identified 350 citations, of which 174 were assessed for eligibility based on title and abstract. The full text of 81 eligible citations was screened, and relevant data of 15 children under 4 years of age with mycobacterial PESAO were extracted. These data were pooled with those from our Institution. Data from 16 children were reviewed. The median age was 16 ± 7 months and the male:female ratio 1.7. The knee was the most common infection site (94%). The diagnosis of mycobacterial disease was delayed in all cases (range, 2 weeks to 6 months), and initially presumed by histology in 15 children (94%). Microbiologically proven diagnosis was confirmed by bone cultures in 8 of the 15 children (53%), and by specific PCR in 2 of the 3 culture-negative bone specimens (67%). Three children experienced long-term orthopedic complications despite surgical drainage and prolonged antimycobacterial regimens. All recently reported cases came from high-burden tuberculosis areas. Mycobacterium species contribute to the burden of infantile PESAO in endemic tuberculosis areas and may cause growth disturbances. We argue in favor of the early recognition of mycobacterial disease by specific molecular assays in children with infantile PESAO living in high-burden areas.

Patterns of Kingella kingae Disease Outbreaks

BACKGROUND

Kingella kingae outbreaks occur sporadically in childcare centers but remain poorly understood and difficult to identify.

METHODS

To provide the basis of a better knowledge of K. kingae outbreaks patterns that may help to guide identification and management strategies, we collected epidemiological, clinical and laboratory data from all reported K. kingae outbreaks, and those from 2 new Israel outbreaks in 2014.

RESULTS

Nine outbreaks were identified in the USA, Israel and France from 2003 to 2014. Twenty-seven children with a median age of 14 ± 4.1 months were affected, male:female ratio of 1.4:1. Outbreaks demonstrated seasonal patterns from the 10th to the 45th weeks, a mean duration of 13.1 ± 8.4 days, a mean attack rate of 17.3 ± 5.1% and a case-fatality rate of 3.7% (1/27). Seventy-four percentage of children had fever (20/27), and the mean values of white blood cell count and C-reactive protein level were 14.6 ± 4.5 × 10/L and 23.8 ± 24.1 mg/L, respectively. Osteoarticular infections accounted for 88.9% of cases (24/27), bacteremia 7.4% (2/27), endocarditis 3.7% (1/27) and meningitis 3.7% (1/27). Specific real-time polymerase chain reaction demonstrated higher performance than culture methods in the diagnosis of case patients and investigations of oropharyngeal K. kingae carriage among close contacts, and multilocus sequence typing methods revealed that ST-6 and ST-25 invasive strains were responsible for multiple country-dependent outbreaks. Coviral infections were identified in the majority of K. kingae outbreaks, notably those causing oral ulcers.

CONCLUSIONS

K. kingae outbreaks displayed severe K. kingae diseases that were poorly confirmed with culture methods. We argue for the use of genomic technologies to investigate further K. kingae outbreaks.