Osteoarticular Infections In Children Research Articles

Interest of a Three Phase Bone Scintigraphy Protocol in the Diagnosis and Management of Osteoarticular Infections in Children. About 31 Cases

Introduction: Osteoarticular infection is a particularly common pathology in children. The diagnosis is sometimes difficult especially in front of a poor symptomatology and a little disturbed biological assessment. The aim of this work is to assess the contribution of bone scintigraphy in the diagnosis of osteoarticular infections in children. Patients and Method: This is a retrospective study spread out between December 2012 and February 2019, involving children referred to the nuclear medicine department of Hassan II University Hospital Center of Fez for suspected osteoarticular infection. All the children benefited from a bone scan with a triple phase acquisition followed by a study of the entire bone skeleton, after an IV injection of 10 MBq /Kg of MDP-Tc99m. Results: We selected 31 children. The average age was 9.43 years old with a male predominance. The clinical signs mainly found in our patients were fever, bone pain and functional impairment of the affected limb. The main location was the lower limb (74.2%). Bone scan was positive in 70.9% of patients, including 9 cases of septic arthritis, 7 cases of osteomyelitis, 4 cases of sacroiliitis and one case of lumbar spondylodiscitis. Conclusions: Three-phases bone scintigraphy protocole with MDP-Tc99m completed with a whole body bone scan should remain the examination of choice in osteoarticular infections in children. This exam makes it possible to retain an accurate diagnosis in an early stage of OAI while the other medical imaging modalities exams being negative. Thus allowing to prevent severe complications with an affordable financial cost and an acceptable irradiation rate.

Clinical and Microbiologic Variables Predictive of Orthopedic Complications Following Staphylococcus aureus Acute Hematogenous Osteoarticular Infections in Children.

Staphylococcus aureus is the most common cause of acute hematogenous osteoarticular infections (AHOAIs) in children. The risk factors for the development of orthopedic complications (OC) after AHOAI are poorly understood. We sought to describe clinical and microbiologic variables present on the index admission that may predict OC in S. aureus AHOAI. Staphylococcus aureus AHOAI cases were identified from 2011-2017 at Texas Children's Hospital and reviewed for the development of OC. OC included chronic osteomyelitis, growth arrest, avascular necrosis, chronic dislocation, and pathologic fracture. All S. aureus isolates were characterized by pulsed-field gel electrophoresis and agr group. A total of 286 cases were examined of which 27 patients (9.4%) developed OC. Patients who developed OC more often had infection with an agr group III organism (P = .04), bacteremia (P = .04), delayed source control (P < .001), ≥2 surgical procedures (P < .001), intensive care unit admission (P = .09), and fever >4 days after admission (P = .008). There was no association with OC and patient age, methicillin resistance, or choice/route of antibiotics. In multivariable analyses of OC, infection with agr group III S. aureus, prolonged fever, and delayed source control remained statistically significant. OC develop following S. aureus AHOAI in 9.4% of cases. Although the development of OC is likely multifactorial, agr group III organisms, prolonged fever, and delayed source control are independently associated with OC. Moreover, early aggressive surgical source control may be beneficial in children with S. aureus AHOAI.

Osteoarticular Infections Following Open or Penetrating Trauma in Children in the Post-Community-Acquired Methicillin-resistant Staphylococcus aureus Era: The Impact of Enterobacter cloacae.

Most cases of pediatric osteoarticular infections (OAIs) are hematogenous in nature and caused by Staphylococcus aureus. OAI in children can also occur through direct inoculation of microorganisms secondary to penetrating or open trauma. No studies in the United States have evaluated the microbiology or outcomes of trauma-related OAI (TROAI) in children in the era of community-acquired methicillin-resistant S. aureus (CA-MRSA). Cases were identified from the inpatient infectious diseases consultation database at Texas Children's Hospital from January 2011 to December 2016. TROAI cases were those in which OAI developed following a clear history of penetrating trauma, open fracture, crush injury or traumatic amputation. Only cases with radiographic evidence of bone abscess, gross appearance of infection at the time of surgery and/or positive cultures from bone or joint were included. Complications included recurrence of infection, pathologic fracture or chronic osteomyelitis. During the study period, 692 consultations for OAI were performed, with 34 meeting inclusion criteria. In 68%, at least 1 organism was isolated, and the most commonly isolated organisms were S. aureus (32% overall, 21% MRSA) and Enterobacter cloacae (24%). Polymicrobial infections occurred in 38% of patients. Eighty-five percentage of patients had at least 1 surgical procedure, and 38% underwent ≥ 2 procedures. Eighty-two percentage of patients were discharged on oral therapy. Complications developed in 15% of patients and were more commonly associated with E. cloacae (80% vs. 14%, P = 0.007) and fungi (P = 0.03). TROAI are relatively uncommon in children but cause significant morbidity. While MRSA contributes substantially to TROAI, the highly diverse microbiology emphasizes the importance of obtaining cultures for microbiologic diagnosis and management. Clinicians should be aware of the frequency of E. cloacae in TROAI and its high risk for sequelae.

919. Clinical and Microbiologic Characteristics Associated With Long-Term Orthopedic Complications Following Staphylococcus aureus Acute Hematogenous Osteoarticular Infections in Children

Background Staphylococcus aureus is the most common cause of acute hematogenous osteoarticular infections (AHOAIs) in children. While the vast majority of patients do well, a small proportion experience significant morbidity, including chronic infection and pathologic fractures. We sought to describe clinical and microbiologic variables present on the index admission that may predict long-term orthopedic complications (OC).MethodsCases of S. aureus AHOAI were identified from 2011 to 2016 at Texas Children’s Hospital (TCH). All cases were reviewed for the development of OC until April 1, 2018. OC included chronic osteomyelitis (CO), growth arrest/limb length discrepancy, avascular necrosis, chronic dislocation, and pathologic fracture (PF) with or without angular deformity. All S. aureus isolates were characterized by PCR for Panton–Valentine Leukocidin (PVL) genes and agr group. Statistical Analyses were performed with STATA.ResultsA total of 252 cases were identified meeting inclusion criteria (figure). Twenty-four (9.5%) developed OC; of which, 50% were CO and 25% PF. Patients who developed CO more often had positive blood cultures during the index admission (P < 0.001), surgical drainage after hospital day 2 (33.3% vs. 8.8%, P = 0.02) as well as a longer time to 50% reduction in C-reactive protein (CRP, 9 vs. 7 days, P = 0.01). Patients who developed PF more often had infection due to PVL-positive organisms (83.3% vs. 38.6%, P = 0.03) and had a longer duration of fever after admission (9.5 vs. 2.5 days, P = 0.03). Overall, OC were associated with ICU admission (P = 0.04), a slower decline in CRP (P = 0.02) and a greater proportion of patients with surgery after hospital day 2 (P = 0.04) as well as infection secondary to agr III isolates (P = 0.03). There was no statistically significant relationship between OC and patient age, affected bone, time to initiation of effective antimicrobial therapy, duration of intravenous therapy, or final antibiotic choice.ConclusionPatients with S. aureus AHOAI with a delay in source control, slow decline in CRP, prolonged fever or ICU admission are at higher risk of OC. While nonspecific, these findings suggest that such patients may warrant especially cautious clinical follow-up to identify sequelae early. Large multicenter studies are needed to better predict OC in this setting. Disclosures All authors: No reported disclosures.

Cytotoxic activity of Kingella kingae RtxA toxin depends on post-translational acylation of lysine residues and cholesterol binding

Kingella kingae is a member of the commensal oropharyngeal flora of young children. Improvements in detection methods have led to the recognition of K. kingae as an emerging pathogen that frequently causes osteoarticular infections in children and a severe form of infective endocarditis in children and adults. Kingella kingae secretes a membrane-damaging RTX (Repeat in ToXin) toxin, RtxA, which is implicated in the development of clinical infections. However, the mechanism by which RtxA recognizes and kills host cells is largely unexplored. To facilitate structure-function studies of RtxA, we have developed a procedure for the overproduction and purification of milligram amounts of biologically active recombinant RtxA. Mass spectrometry analysis revealed the activation of RtxA by post-translational fatty acyl modification on the lysine residues 558 and/or 689 by the fatty-acyltransferase RtxC. Acylated RtxA was toxic to various human cells in a calcium-dependent manner and possessed pore-forming activity in planar lipid bilayers. Using various biochemical and biophysical approaches, we demonstrated that cholesterol facilitates the interaction of RtxA with artificial and cell membranes. The results of analyses using RtxA mutant variants suggested that the interaction between the toxin and cholesterol occurs via two cholesterol recognition/interaction amino acid consensus motifs located in the C-terminal portion of the pore-forming domain of the toxin. Based on our observations, we conclude that the cytotoxic activity of RtxA depends on post-translational acylation of the K558 and/or K689 residues and on the toxin binding to cholesterol in the membrane.

Staphylococcus aureus osteoarticular infections in children: an 8-year review of molecular microbiology, antibiotic resistance and clinical characteristics

To investigate the clinical, phenotypic and genotypic characteristics of Staphylococcus aureus strains causing osteoarticular infections in a large paediatric series. Medical records of children who were hospitalized with the diagnosis of community-associated S. aureus (CA-SA) osteomyelitis and/or septic arthritis in the two major tertiary paediatric hospitals of Athens during an 8-year period (2007-2015) were reviewed, and S. aureus isolates were analysed regarding antimicrobial resistance, detection of pathogenicity genes and genotyping using SCCmec, agr typing, PFGE and MLST. During the study period, 123 children with CA-SA osteoarticular infections were identified, and methicillin-resistant S. aureus (MRSA) accounted for 44 of these (35.8 %). Children with MRSA infection had a significantly higher admission rate to the ICU (5.7 vs 0 %, P=0.04) and longer duration of hospitalization (21.6 vs 16.7 days, P=0.04). Sixty-eight isolates [42 (methicillin-sensitive S. aureus) MSSA and 26 MRSA] were available for molecular analysis. All MRSA strains were mecA-positive and most carried the SCCmec IV cassette (23/26, 88 %) and belonged to the PFGE type C (24/26, 92.3 %), agr type 3 (24/26, 92.3 %) and the MLST ST80 clone (24/26, 92.3 %). In contrast, MSSA strains showed polyclonality by PFGE and agr typing. Regarding pathogenicity genes, MRSA vs MSSA isolates showed higher detection rates of PVL (96.2 vs 4.8 %, P<0.0001) and fib (80.8 vs 50 %, P=0.02). In our study a considerable number of S. aureus osteoarticular infections were due to CA-MRSA isolates, most of which belonged to the ST80 clone and had a higher incidence of specific virulence factors, entailing higher ICU admission rates and a longer duration of hospitalization.

Diagnosis and management of acute osteoarticular infections in children.

Acute hematogenous osteomyelitis and septic arthritis are not uncommon infections in children and should be considered as part of the differential diagnosis of limb pain and pseudoparalysis. Most bone infections in children arise secondary to hematogenous seeding of bacteria into bone. The most common pathogens are Staphylococcus aureus and Kingella kingae. Children with septic arthritis should be evaluated promptly by orthopedic specialists for aspiration and possible debridement of concomitant osteomyelitis. Optimal empiric therapy after appropriate cultures continues to be intravenous cefazolin. In most cases, conversion to oral antimicrobials should occur when the patient has clinically improved and has decreasing inflammatory markers. For most uncomplicated cases of osteomyelitis, current recommendations are 3 to 4 weeks of antimicrobial therapy compared with the 6 weeks previously recommended.

Pediatric Methicillin-Resistant Staphylococcus aureus Osteoarticular Infections.

Osteoarticular infections (OSI) are a significant cause of hospitalizations and morbidity in young children. The pediatric patient with OSI presents unique challenges in diagnosis and management due to higher morbidity, effect on growth plate with associated long-lasting sequelae, and challenges in early identification and management. Methicillin-resistant Staphylococcus aureus (MRSA), first described in the 1960s, has evolved rapidly to emerge as a predominant cause of OSI in children, and therefore empiric treatment for OSI should include an antibiotic effective against MRSA. Characterizing MRSA strains can be done by antimicrobial susceptibility testing, detection of Panton–Valentine leukocidin (PVL) gene, staphylococcal cassette chromosome mec (SCCmec) typing, pulsed-field gel electrophoresis (PFGE), and multilocus sequence typing (MLST). Worldwide, community-onset methicillin-resistant staphylococcal disease is widespread and is mainly associated with a PVL-producing clone, ST8/USA300. Many studies have implied a correlation between PVL genes and more severe infection. We review MRSA OSI along with the pertinent aspects of its pathogenesis, clinical spectrum, diagnosis, and current guidelines for management.

Association of Vancomycin MIC and Molecular Characteristics with Clinical Outcomes in Methicillin-Susceptible Staphylococcus aureus Acute Hematogenous Osteoarticular Infections in Children.

Strains of methicillin-resistant Staphylococcus aureus (MRSA), particularly those belonging to the USA300 pulsotype, have been well described to cause severe osteoarticular infections (OAIs). A vancomycin MIC of ≥1.5 μg/ml has been demonstrated to contribute to disease severity in adults with MRSA and even methicillin-susceptible S. aureus (MSSA) bacteremia. Little data exist describing the outcomes of MSSA OAIs in terms of molecular characteristics and vancomycin MIC. All patients/isolates were chosen from a surveillance study at Texas Children's Hospital (TCH). S. aureus OAI isolates were identified from 2011 to 2016 and subjected to vancomycin Etests, pulsed-field gel electrophoresis (PFGE), and PCR to determine Panton-Valentine leucocidin (PVL) production and agr group. Two hundred fifty-two cases of S. aureus OAI were identified; 183 cases were MSSA (72.6%). During the study period, a decrease in the proportion of cases secondary to MRSA was observed, declining from 37.8% to 15.9% (P = 0.02). Of the MSSA isolates, 26.2% and 23.5% were USA300 and PVL positive, respectively. An increase in the proportion of MSSA isolates with a vancomycin MIC of ≥1.5 μg/ml occurred in the study period (P = 0.004). In MSSA, an elevated vancomycin MIC was associated with multiple surgical procedures and venous thromboses, even when adjusting for empirical β-lactam use. An increase in vancomycin MIC was noted among isolates belonging to agr group 4 during the study period. Methicillin resistance is declining among S. aureus OAI isolates at TCH. Simultaneously, vancomycin Etest MICs are increasing among MSSA isolates. Vancomycin MICs of ≥2 μg/ml are associated with adverse clinical outcomes in MSSA irrespective of antibiotic choice, suggesting that this may be a surrogate for organism virulence.

Real-Time PCR Assay for Detection of Kingella kingae in Children

Background Kingella kingae is a known cause of osteoarticular infections in children younger than 4 years of age, but it is not always recoverable in culture. Molecular methods are increasingly used for diagnosis. Methods To facilitate diagnosis of K. kingae septic arthritis, we developed a real-time polymerase chain reaction (PCR) assay for the detection of K. kingae that targets the repeat-in-toxin gene (rtxB). Results We present three pediatric patients with K. kingae septic arthritis at our institution who were diagnosed using the real-time PCR assay. All underwent arthrotomy with irrigation and debridement and were symptom-free after 3 weeks of therapy with β-lactam antibiotics. Cultures of synovial fluid or tissue grew K. kingae in two of three; K. kingae real-time PCR was positive in all three patients. In addition, 11 cases of K. kingae osteoarticular infection were diagnosed through Mayo Medical Laboratories using this assay. The limit of detection of the real-time PCR assay was 73.7 colony-forming unit (CFU)/µL for tissue and 1.3 CFU/µL for synovial fluid. Conclusions PCR-based detection methods are faster and more sensitive than conventional culture-based methods for the diagnosis of K. kingae osteoarticular infections in children.

The Contemporary Bacteriologic Epidemiology of Osteoarticular Infections in Children in Switzerland

To assess the contemporary bacteriologic epidemiology of pediatric osteoarticular infection with particular regard to children's ages, because Kingella kingae has gained increasing recognition as the predominant pathogen for osteoarticular infection in young children. Retrospective file review of enrolled children from 0 to 15 years of age, admitted to our institution from 2007 to 2015 for suspected osteoarticular infection (217 cases). Information on age, sex, the bone or joint infected, imaging studies, and laboratory data (including bacterial investigations) were collected for analysis. Microorganism identification was possible for 138 infected children (63.6%), through blood (cultures or polymerase chain reaction [PCR]) and/or operative samples (cultures or PCR). Thirty-one patients (14.3%) were found to both have positive blood cultures and operative samples. The results of positive bacteriology specimens identified the most common causative pathogen for osteoarticular infection as K kingae (47.8% of microbiologically confirmed osteoarticular infections of all ages, and 87.7% in children between the ages of 6 and 48 months), significantly more common than Staphylococcus aureus (35.5% of microbiologically confirmed osteoarticular infections of all ages, and 78.2% in children >4 years of age). Use of the appropriate PCR assays demonstrated that K kingae currently is the major bacterial cause of pediatric osteoarticular infection, especially in children <4 years of age in whom K kingae is more common than S aureus. PCR assays should be used in routine microbiologic laboratory evaluation to improve diagnostic performance. However, despite the use of molecular methods, there are many osteoarticular infections in which no microorganism is detected, which suggests that these infections may be caused by other as yet unrecognized fastidious microorganisms.

Atypical causes of bacterial osteoarticular infections in immunocompetent children.

Caring for a child with an osteoarticular infection or considering the possibility of an osteoarticular infection in a child is one of the most common clinical dilemmas encountered by clinicians caring for children. In such a scenario, one most often considers infection with frequently encountered pathogens such as Staphylococcus aureus, Streptococcus pyogenes, Streptococcus pneumoniae or Kingella kingae. A large variety of opportunistic osteoarticular pathogens may be found in the immunosuppressed patient or the postoperative or post-trauma patient, due to breaches in the immune system and nosocomial or post-traumatic exposure to multiple organisms. However, an enlarging spectrum of less commonly encountered bacterial pathogens is also increasingly appreciated in community-acquired osteoarticular infections in otherwise healthy children, particularly in this era of pneumococcal and Haemophilus influenzae serotype B immunization. Given the limitations of culture-based detection methods in osteoarticular infections and the potentially unique therapeutic and diagnostic approaches necessitated by some of these pathogens, an awareness of these infections is necessary for proper detection and management. This review will discuss less commonly encountered bacterial osteoarticular pathogens that may infect otherwise healthy children, with emphasis on the epidemiology, diagnosis and treatment of each.

Etiology and evolution of the osteoarticular infections. 2009-2015: Pediatric Hospital Pereira Rossell Uruguay

The most frequent osteoarticular infections (OAI) etiological agent is Staphylococcus aureus. The prevalence of other microorganisms has changed after the introduction of new vaccines. To describe the etiology and evolution of the OAIs in children hospitalized in Pediatric Hospital Pereira Rossell between 2009 and 2015. Joint fluid and bone puncture studies of hospitalized children suspected of OAI. Epidemiological characteristics, isolated microorganisms, complementary tests, initial treatment, complications, and days of hospitalization were analyzed. 335 patients; the etiology was established in 113. Clinical data could be analyzed in 87 cases. The average age was 6.1 years. They corresponded to: methicillin-sensitive S. aureus (n: 47), community-acquired methicillin-resistant S. aureus (CA-MRSA) (n: 11), Streptococcus pyogenes (n: 6), Streptococcus pneumoniae (n: 1), Haemophilus influenzae type b (n: 2), Gram-negative bacilli (n: 9), Kingella kingae (n: 1) others (n: 6). In 4 cases, more than one microorganism was isolated. CA-MRSA infections were more serious. A decrease is observed in the number of CA-MRSA isolates. A fact to be highlighted is the impact of universal vaccination against S. pneumoniae and H. influenzae type b. It is a finding to be monitored the increasing number of Gram-negative bacilli isolates.

The Influence of the Route of Antibiotic Administration, Methicillin Susceptibility, Vancomycin Duration and Serum Trough Concentration on Outcomes of Pediatric Staphylococcus aureus Bacteremic Osteoarticular Infection.

Bacteremia is often one factor used in deciding the need for prolonged intravenous antimicrobial therapy in osteoarticular infections (OAIs). We examined treatment practices and outcomes of Staphylococcus aureus bacteremic osteoarticular infections (BOAIs) evaluated at Texas Children's Hospital. Cases of acute hematogenous OAI in children with positive blood cultures for S. aureus at Texas Children's Hospital between 2011 and 2014 were reviewed. Orthopedic complications included chronic osteomyelitis, growth arrest, pathologic fracture, avascular necrosis and chronic dislocation. Acute kidney injury was defined as a doubling of the baseline creatinine. One hundred and ninety-two cases of S. aureus OAI were identified with 102 cases of BOAI included [35 methicillin-resistant S. aureus (MRSA)]. Twenty-five patients were discharged home on oral antibiotics. Patients discharged on oral antibiotics had a shorter duration of fever, had a more rapid decline in C-reactive protein and were less likely to have MRSA. The frequency of orthopedic complications did not increase in patients who received early transition to oral antibiotics. For patients with MRSA bacteremia, the rates of complications between those who received ≥7 days versus <7 days of vancomycin did not differ. Vancomycin serum troughs >15 µg/mL were not associated with a decreased duration of fever, bacteremia or hospitalization, need for repeat operation or orthopedic complications but were associated with acute kidney injury. S. aureus BOAIs are associated with substantial morbidity. Early transition to oral therapy may be a safe option for select patients with S. aureus BOAI, including those due to MRSA. Prolonged courses of vancomycin and vancomycin troughs >15 μg/mL were not associated with improved outcomes for MRSA OAI.

Osteoarticular Infections Following Open or Penetrating Trauma in Children in the Era of Community-Acquired MRSA

BackgroundMost cases of pediatric osteoarticular infections (OAI) are hematogenous in nature and secondary to Staphylococcus aureus. The emergence of community-acquired MRSA (CA-MRSA) in the early 2000s led to an evolution of disease presentation and management for pediatric OAI. OAI in children can also occur through direct inoculation of microorganisms secondary to penetrating or open trauma. No studies have evaluated the microbiology or outcomes of trauma-related OAI (TROAI) in children in the era of CA-MRSA.MethodsCases were identified from the inpatient infectious diseases consultation database at Texas Children’s Hospital from Jan 1, 2011- Dec 31, 2016. TROAI cases were those in which OAI developed following a clear history of penetrating trauma, open fracture, crush injury or traumatic amputation. Only cases with radiographic evidence of bone abscess, gross appearance of infection at time of surgery and/or positive cultures from bone or joint were included. Complications included recurrence of infection, pathologic fracture or chronic osteomyelitis.Results692 consultations for OAI were performed during the study period with 32 meeting inclusion criteria; TROAI accounted for 2.8/10,000 hospital admissions. The median age of patients was 8.53 years. In 65.6% at least one organism was isolated and the most commonly isolated organisms were S. aureus (25%, 15.6% MRSA) and Enterobacter cloacae (25%, Figures 1 and 2). 83.9% of patients had at least one surgical procedure and 43.8% underwent ≥2 procedures. The presence of fungi (P = 0.01), atypical mycobacteria (P = 0.04), MRSA (P = 0.02) and/or polymicrobial infection (P = 0.001) were more common among cases requiring multiple surgeries. 84.4% of patients were discharged on oral therapy. 12.5% of patients developed complications and this was more common with E. cloacae (37.5% vs. 4.2%, P = 0.03).ConclusionTROAI are relatively uncommon in children but cause significant morbidity. While MRSA contributes substantially to TROAI and is associated with multiple surgical procedures, the highly diverse microbiology emphasizes the importance of obtaining cultures for microbiologic diagnosis and management. Clinicians should be aware of the frequency of E. cloacae in TROAI and its high risk for sequelae.Disclosures S. L. Kaplan, Allergan: Grant Investigator, Grant recipient and This grant pertains to unrelated research

Epidemiology and Management of Acute, Uncomplicated Septic Arthritis and Osteomyelitis: Spanish Multicenter Study.

Acute osteoarticular infection (OAI) is a potentially severe disease. The aim of this study was to evaluate the etiology, clinical characteristics and therapeutic approach of OAI in children in Spain. Medical records from children <14 years with OAI from 25 hospitals between 2008 and 2012 were reviewed. Confirmed osteomyelitis (OM) and septic arthritis (SA) required a positive bacterial isolate; otherwise, they were considered probable. Probable SA with <40,000 cells/mm in joint fluid was not included. A total of 641 children were evaluated. Two hundred and ninety-nine cases (46%) were OM, 232 (36%) SA, 77 (12%) osteoarthritis and 33 (5%) spondylodiscitis. Children with OM were older (63 vs. 43 months for SA; P < 0.001). Magnetic resonance imaging and bone scintigraphy had the highest yield for OM diagnosis (94%). Arthrocentesis was performed in 96% of SA. A microorganism was isolated in 246 patients (38%: 33% OM vs. 55% SA; P < 0.001): Staphylococcus aureus was the most common (63%), followed by Kingella kingae (15%) and Streptococcus pyogenes (9%). Ninety-five percent of children initially received IV antibiotics, mostly cefotaxime + cloxacillin (60%) or cloxacillin (40%). Total treatment duration was 38 (±31) days for OM and 28 (±16) days for SA (P < 0.0001). Twenty percent of children with OM (46% because of complications) and 53% with SA (95% initial arthrotomy) underwent surgery. Patients with SA were compared according to initial arthrotomy (n = 123) versus arthrocentesis (n = 109), and no clinical differences were observed, except for higher rate of hip SA in the former (50% vs. 9%; P < 0.001). Children with arthrocentesis had less sequelae [6.6% vs. 1%; P = 0.03, odds ratio = 0.58 (95% confidence interval: 0.45-0.76)], but not in the multivariate analysis. This is the largest pediatric cohort of OAI in Spain. S. aureus was the most common isolate, although K. kingae was recovered in a high proportion of cases. Conservative management was applied in half of the patients. There was a low rate of sequelae, even with nonsurgical approaches.

Sequential Intravenous High Dose Oral Antibiotics in the Treatment of Osteoarticular Infections in Children: A Randomized Controlled Trial

Sequential Intravenous High Dose Oral Antibiotics in the Treatment of Osteoarticular Infections in Children: A Randomized Controlled Trial

Unusual case of paediatric septic arthritis of the lumbar facet joints due to Kingella kingae

A 32-month-old boy presented with febrile limping that had developed over 6days, associated with right lumbosacral inflammatory swelling. Magnetic resonance imaging (MRI) showed joint effusion of the right L5–S1 zygapophyseal joint, complicated by destructive osteomyelitis of the L5 articular process and paraspinal abscess. Surgery was decided to evacuate the fluid accumulation and rule out differential diagnoses. The diagnosis of septic arthritis of the facet joint was confirmed intraoperatively; real-time quantitative PCR analysis identified Kingella kingae. This is the first substantiated paediatric case of zygapophyseal joint septic arthritis due to K. kingae. K. kingae is the most common pathogen responsible for invasive osteoarticular infection in children under 4years of age. Since empiric antibiotics are effective in early stages, physicians should consider the possibility of spinal infections due to K. kingae when a limping child under 4years of age presents with a fever.

Bone and Joint Infections in Children: Acute Hematogenous Osteomyelitis.

Acute hematogenous osteomyelitis (AHO) is one of the commonest bone infection in childhood. Staphylococcus aureus is the commonest organism causing AHO. With use of advanced diagnostic methods, fastidious Kingella kingae is increasingly becoming an important organism in etiology of osteoarticular infections in children under the age of 3y. The diagnosis of AHO is primarily clinical. The main clinical symptom and sign in AHO is pain and tenderness over the affected bone especially in the metaphyseal region. However, in a neonate the clinical presentation may be subtle and misleading. Laboratory and radiological investigations supplement the clinical findings. The acute phase reactants such as C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) are frequently elevated. Ultrasonography and MRI are key imaging modalities for early detection of AHO. Determination of infecting organism in AHO is the key to the correct antibiotic choice, treatment duration and overall management and therefore, organism isolation using blood cultures and site aspiration should be attempted. Several effective antibiotics regimes are available for managing AHO in children. The choice of antibiotic and its duration and mode of delivery requires individualization depending upon severity of infection, causative organism, regional sensitivity patterns, time elapsed between onset of symptoms and child's presentation and the clinical and laboratory response to the treatment. If pus has been evidenced in the soft tissues or bone region, surgical decompression of abscess is mandatory.

Microbiological characteristics of acute osteoarticular infections in children.

This study aimed to describe the microbiological characteristics of acute septic arthritis (SA) and osteomyelitis (OM) in children. Cases of children (0-15 years) with SA/OM were identified through a retrospective search of hospital discharge codes over a six-year period. In addition, a systematic literature search and meta-analysis of studies reporting culture results of children with SA/OM was performed. In our retrospective chart review, we identified 65 cases of OM and 46 cases of SA. The most frequently cultured organisms in both conditions were Gram-positive cocci, primarily Staphylococcus aureus. On admission, most patients had a normal white blood cell count (WCC) but elevated C-reactive protein (CRP) and/or erythrocyte sedimentation rate (ESR). Bacteraemia was associated with a longer mean length of hospitalization for both infections. Considering our results and the meta-analysis, we found low rates of culture-positivity in cases of clinically confirmed infection. In SA, articular fluid was culture-positive in 42.49% [95% confidence interval (CI) 28.39-57.23]. In OM, intra-operative samples were culture-positive in 52.65% (95% CI 30.54-74.22). Bacteraemia was detected in 23.91% (95% CI 8.40-44.24) of children with SA and 21.48% (95% CI 10.89-34.47) with OM. Despite appropriate sampling, a positive microbiological diagnosis is often lacking in paediatric acute osteoarticular infection using standard culture-based methods. This highlights the need for validation and use of more sensitive diagnostic methods, such as PCR.