Aetiology of arthritis in hospitalised children: an observational study

SPILF update on bacterial arthritis in adults and children

In 2020 the French Society of Rhumatology (SFR) published an update of the 1990 recommendations for management of bacterial arthritis in adults. While we (French ID Society, SPILF) totally endorse this update, we wished to provide further information about specific antibiotic treatments. The present update focuses on antibiotics with good distribution in bone and joint. It is important to monitor their dosage, which should be maximized according to PK/PD parameters. Dosages proposed in this update are high, with the optimized mode of administration for intravenous betalactams (continuous or intermittent infusion). We give tools for the best dosage adaptation to conditions such as obesity or renal insufficiency. In case of enterobacter infection, with an antibiogram result "susceptible for high dosage", we recommend the requesting of specialized advice from an ID physician. More often than not, it is possible to prescribe antibiotics via the oral route as soon as blood cultures are sterile and clinical have symptoms shown improvement. Duration of antibiotic treatment is 6 weeks for Staphylococcus aureus, and 4 weeks for the other bacteria (except for Neisseria: 7 days).

Clinical Overview of Arthritis with a Focus on Management Options and Preventive Lifestyle Measures for Its Control

ABSTRACT:

Arthritis is the spectrum of conditions that cause swelling and tenderness of one or more body joints with key symptoms of joint pain and stiffness. Its progression is closely tied to age. Although there are a number of arthritis types, such as, ankylosing, gout, joint infections, juvenile idiopathic, reactive and septic; the two most common types are osteoarthritis and rheumatoid arthritis. Osteoarthritis causes the articulating smooth cartilage that covers the ends of bones, where they form a joint, to breakdown. Rheumatoid arthritis is a disease in which the immune system attacks joints, beginning with the cartilaginous lining of the joints. The latter is considered a systemic disease, i.e. affecting many parts of the body, but the respiratory system is involved in 10 to 20 % of all mortality. Osteoarthritis is one of the leading causes of disability globally. Several preventive measures to control arthritis have been suggested, such as the use of analgesics, non-steroid anti-inflammatory drugs, moderate to vigorous physical activity and exercise, reducing sedentary hours, getting adequate sleep and maintaining a healthy body weight. Foods including, a Mediterranean diet rich in fruits and vegetables, fish oil, medicinal plants and microbiota are vital protective methods. The intake of vitamins such as A and C, minerals e.g., selenium and zinc; poly unsaturated and n-3 fatty acids is also a significant preventive measures.

Microbiology of septic arthritis in young Auckland children

BACKGROUND

Kingella kingae is an important cause of septic arthritis in young children, with modern laboratory methods leading to increased detection. Prevalence of this pathogen in New Zealand, where there are high rates of childhood infections due to Staphylococcus aureus and Streptococcus pyogenes, is not known.

METHODS

We conducted a retrospective review of children <5 years with septic arthritis (without osteomyelitis) at a tertiary children's hospital in Auckland, over 10 years (2005-2014). Data were collected on demographics, microbiology, clinical presentation, investigations and management.

RESULTS

Of the 68 cases of septic arthritis, 57 (83.8%) occurred in children aged <24 months. Among those <3 months, Streptococcus agalactiae (Group B streptococcus) was predominant (45.5% of 11 cases), followed by S. aureus (36.4%). The most common pathogen in those 3 to <12 months was Streptococcus pneumoniae (38.5% of 13 cases). In children aged 12 to <24 months, K. kingae was most common (30.3% of 33 cases). Of the 12 cases of K. kingae, 91.7% were identified from synovial fluid culture. All K. kingae isolates were susceptible to amoxicillin.

CONCLUSIONS

K. kingae is the leading pathogen in septic arthritis in New Zealand children aged 12 to <24 months. Routine inoculation of synovial fluid into blood culture bottles at time of sample collection, in addition to use of polymerase chain reaction methods, should be encouraged to improve detection rates. For infants and preschool children presenting with single joint septic arthritis, empiric antibiotics should include cover for S. aureus and K. kingae.

First report of Kingella kingae diagnosed in pediatric bone and joint infections in Morocco

BACKGROUND

The progress of diagnostic strategies and molecular methods improved the detection of Kingella kingae in bone and joint infections, and now, Kingella kingae is being increasingly recognized as the most frequent cause of bone and joint infection BJI in early childhood. The main objective of this prospective study is to report the frequency of Kingella Kingae in negative culture bone and joint pediatric infections, and to describe the clinical and biologic features of these children.

METHODS

From December 2016 to June 2019, we selected all hospitalized patients with suspected BJI. When culture was negative on the fifth day, children under 10 years were subsequently included in the study, and PCR assay was performed systematically for researching K. kingae specific gene cpn60. Microbial culture and identification were made using standard bacteriological methods. The demographics, clinical, laboratory, radiographic and clinical features were reviewed from medical records.

RESULTS

We enrolled 65 children with culture negative BJI, 46 of them having under 10 years old have been screened for the cpn60 gene. Thus, the gene encoding Kingella kingae was positive for 27 BJI cases (58.7%). The mean age of children was 3.02 years, 55.6% were aged 6 months-4 years and 29.6% of them were aged 5-10 years. The male to female ratio was 1.7 and 16 cases (59.26%) occurred during the fall-winter period. The most frequent BJI type was septic arthritis (77.8%) and the most affected sites were knee (51.9%) and hip (37.0%). We recorded a mild clinical picture with normal to mildly raised inflammatory markers. All patients had good clinical and functional outcomes, with no serious orthopedic sequelae..

CONCLUSION

K kingae is an important pathogen of culture-negative BJI in Moroccan children. PCR testing should be performed in culture-negative cases of children not only in the typical age range of 6 months to 4 years. When implemented in the routine clinical microbiology laboratory, a specific K. kingae PCR assay can provide a better diagnostic performance of BJI.

Kingella kingae Displaced S. aureus as the Most Common Cause of Acute Septic Arthritis in Children of All Ages

BACKGROUND

Acute septic arthritis (SA) still remains a challenge with significant worldwide morbidity. In recent years, Kingella kingae has emerged and treatment regimens have become shorter. We aim to analyze trends in SA etiology and management and to identify risk factors for complications.

METHODS

Longitudinal observational, single center study of children (<18 years old) with SA admitted to a tertiary care pediatric hospital, from 2003 to 2018, in 2 cohorts, before and after implementation of nucleic acid amplification assays (2014). Clinical, treatment and disease progression data were obtained.

RESULTS

A total of 247 children were identified, with an average annual incidence of 24.9/100,000, 57.9% males with a median age of 2 (1-6) years. In the last 5 years, a 1.7-fold increase in the annual incidence, a lower median age at diagnosis and an improved microbiologic yield (49%) was noticed. K. kingae became the most frequent bacteria (51.9%) followed by MSSA (19.2%) and S. pyogenes (9.6%). Children were more often treated for fewer intravenous days (10.7 vs. 13.2 days, P = 0.01) but had more complications (20.6% vs. 11.4%, P = 0.049) with a similar sequelae rate (3.7%). Risk factors for complications were C-reactive protein ≥80 mg/L and Staphylococcus aureus infection, and for sequelae at 6 months, age ≥4 years and CRP ≥ 80 mg/L.

CONCLUSIONS

The present study confirms that K. kingae was the most common causative organism of acute SA. There was a trend, although small, for decreasing antibiotic duration. Older children with high inflammatory parameters might be at higher risk of sequelae.

Acute monoarthritis in young children: comparing the characteristics of patients with juvenile idiopathic arthritis versus septic and undifferentiated arthritis

Acute arthritis is a common cause of consultation in pediatric emergency wards. Arthritis can be caused by juvenile idiopathic arthritis (JIA), septic (SA) or remain undetermined (UA). In young children, SA is mainly caused by Kingella kingae (KK), a hard to grow bacteria leading generally to a mild clinical and biological form of SA. An early accurate diagnosis between KK-SA and early-onset JIA is essential to provide appropriate treatment and follow-up. The aim of this work was to compare clinical and biological characteristics, length of hospital stays, duration of intravenous (IV) antibiotics exposure and use of invasive surgical management of patients under 6 years of age hospitalized for acute monoarthritis with a final diagnosis of JIA, SA or UA. We retrospectively analyzed data from < 6-year-old children, hospitalized at a French tertiary center for acute mono-arthritis, who underwent a joint aspiration. Non-parametric tests were performed to compare children with JIA, SA or UA. Bonferroni correction for multiple comparisons was applied with threshold for significance at 0.025. Among the 196 included patients, 110 (56.1%) had SA, 20 (10.2%) had JIA and 66 (33.7%) had UA. Patients with JIA were older when compared to SA (2.7 years [1.8–3.6] versus 1.4 [1.1–2.1], p < 0.001). Presence of fever was not different between JIA and SA or UA. White blood cells in serum were lower in JIA (11.2 × 10⁹/L [10–13.6]) when compared to SA (13.2 × 10⁹/L [11–16.6]), p = 0.01. In synovial fluid leucocytes were higher in SA 105.5 × 10³ cells/mm³ [46–211] compared to JIA and UA (42 × 10³ cells/mm³ [6.4–59.2] and 7.29 × 10³ cells/mm³ [2.1–72] respectively), p < 0.001. Intravenous antibiotics were administered to 95% of children with JIA, 100% of patients with SA, and 95.4% of UA. Arthrotomy-lavage was performed in 66.7% of patients with JIA, 79.6% of patients with SA, and 71.1% of patients with UA. In children less than 6 years of age with acute mono-arthritis, the clinical and biological parameters currently used do not reliably differentiate between JIA, AS and UA. JIA subgroups that present a diagnostic problem at the onset of monoarthritis before the age of 6 years, are oligoarticular JIA and systemic JIA with hip arthritis. The development of new biomarkers will be required to distinguish JIA and AS caused by Kingellakingae in these patients.

Differential Accumulation and Activation of Monocyte and Dendritic Cell Subsets in Inflamed Synovial Fluid Discriminates Between Juvenile Idiopathic Arthritis and Septic Arthritis

Despite their distinct etiology, several lines of evidence suggest that innate immunity plays a pivotal role in both juvenile idiopathic arthritis (JIA) and septic arthritis (SA) pathophysiology. Indeed, monocytes and dendritic cells (DC) are involved in the first line of defense against pathogens and play a critical role in initiating and orchestrating the immune response. The aim of this study was to compare the number and phenotype of monocytes and DCs in peripheral blood (PB) and synovial fluid (SF) from patients with JIA and SA to identify specific cell subsets and activation markers associated with pathophysiological mechanisms and that could be used as biomarkers to discriminate both diseases. The proportion of intermediate and non-classical monocytes in the SF and PB, respectively, were significantly higher in JIA than in SA patients. In contrast the proportion of classical monocytes and their absolute numbers were higher in the SF from SA compared with JIA patients. Higher expression of CD64 on non-classical monocyte was observed in PB from SA compared with JIA patients. In SF, higher expression of CD64 on classical and intermediate monocyte as well as higher CD163 expression on intermediate monocytes was observed in SA compared with JIA patients. Moreover, whereas the number of conventional (cDC), plasmacytoid (pDC) and inflammatory (infDC) DCs was comparable between groups in PB, the number of CD141⁺ cDCs and CD123⁺ pDCs in the SF was significantly higher in JIA than in SA patients. CD14⁺ infDCs represented the major DC subset in the SF of both groups with potent activation assessed by high expression of HLA-DR and CD86 and significant up-regulation of HLA-DR expression in SA compared with JIA patients. Finally, higher activation of SF DC subsets was monitored in SA compared with JIA with significant up-regulation of CD86 and PDL2 expression on several DC subsets. Our results show the differential accumulation and activation of innate immune cells between septic and inflammatory arthritis. They strongly indicate that the relative high numbers of CD141⁺ cDC and CD123⁺ pDCs in SF are specific for JIA while the over-activation of DC and monocyte subsets is specific for SA.

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.

Clinical Features and Outcomes of Children with Culture-Negative Septic Arthritis

BACKGROUND

Septic arthritis is a serious infection, but the results of blood and joint fluid cultures are often negative in children. We describe here the clinical features and management of culture-negative septic arthritis in children at our hospital and their outcomes.

METHODS

We performed a retrospective review of a cohort of children with septic arthritis who were hospitalized at Children's Hospital of Philadelphia between January 2002 and December 2014. Culture-negative septic arthritis was defined as a joint white blood cell count of >50000/μL with associated symptoms, a clinical diagnosis of septic arthritis, and a negative culture result. Children with pretreatment, an intensive case unit admission, Lyme arthritis, immunodeficiency, or surgical hardware were excluded. Treatment failure included a change in antibiotics, surgery, and/or reevaluation because of a lack of improvement/worsening.

RESULTS

We identified 157 children with septic arthritis. The patients with concurrent osteomyelitis (n = 28) had higher inflammatory marker levels at presentation, had a longer duration of symptoms (median, 4.5 vs 3 days, respectively; P < .001), and more often had bacteremia (46.4% vs 6.2%, respectively; P < .001). Among children with septic arthritis without associated osteomyelitis, 69% (89 of 129) had negative culture results. These children had lower C-reactive protein levels (median, 4.0 vs 7.3 mg/dL, respectively; P = .001) and erythrocyte sedimentation rates (median, 39 vs 51 mm/hour, respectively; P = .01) at admission and less often had foot/ankle involvement (P = .02). Among the children with culture-negative septic arthritis, the inpatient treatment failure rate was 9.1%, and treatment failure was more common in boys than in girls (17.1% vs 3.8%, respectively; P = .03). We found no association between treatment failure and empiric antibiotics or patient age. No outpatient treatment failures occurred during the 6-month follow-up period, although 17% of the children discharged with a peripherally inserted central catheter line experienced complications, including 3 with bacteremia.

CONCLUSIONS

The majority of septic arthritis infections at our institution were culture negative. Among patients with culture-negative infection, empiric antibiotics failed for 9% and necessitated a change in therapy. More sensitive diagnostic testing should be implemented to elucidate the causes of culture-negative septic arthritis in children.

Acute rheumatic fever

Acute rheumatic fever is caused by an autoimmune response to throat infection with Streptococcus pyogenes. Cardiac involvement during acute rheumatic fever can result in rheumatic heart disease, which can cause heart failure and premature mortality. Poverty and household overcrowding are associated with an increased prevalence of acute rheumatic fever and rheumatic heart disease, both of which remain a public health problem in many low-income countries. Control efforts are hampered by the scarcity of accurate data on disease burden, and effective approaches to diagnosis, prevention, and treatment. The diagnosis of acute rheumatic fever is entirely clinical, without any laboratory gold standard, and no treatments have been shown to reduce progression to rheumatic heart disease. Prevention mainly relies on the prompt recognition and treatment of streptococcal pharyngitis, and avoidance of recurrent infection using long-term antibiotics. But evidence for the effectiveness of either approach is not strong. High-quality research is urgently needed to guide efforts to reduce acute rheumatic fever incidence and prevent progression to rheumatic heart disease.

Imaging of Kingella kingae musculoskeletal infections in children: a series of 5 cases

PURPOSE

Kingella kingae musculoskeletal infections continue to be under-diagnosed and there remains a paucity of literature on its imaging features. The purpose of this manuscript is to review the imaging, clinical, and laboratory findings of microbiology-proven K. kingae infections.

MATERIALS AND METHODS

A retrospective review of musculoskeletal infections between January 1, 2013 and Dec 31, 2016 yielded 134 patients from whom 5 patients had confirmed K. kingae infections (3 boys and 2 girls, mean age of 16 months, range 9-38 months). Picture archiving and communication system and electronic medical records were reviewed.

RESULTS

At presentation, none of the patients had a fever and not all patients had abnormal inflammatory markers. Three patients had septic arthritis (2 knee and 1 sternomanubrial joints), one had epiphyseal osteomyelitis, and one had lumbar spondylodiscitis. The case of epiphyseal osteomyelitis of the distal humerus also had elbow joint involvement. A combination of radiography (n = 4), ultrasound (n = 2), and magnetic resonance (MR) imaging (n = 5) were performed. Prominent synovial thickening was observed for both knee and elbow joints and extensive regional myositis for all except for the patient with sternomanubrial joint infection. The diagnosis of K. kingae infection resulted in a change in the antibiotic regimen in 80% of the patients.

CONCLUSION

Disproportionate synovial thickening, prominent peri-articular myositis, and/or characteristic sites of involvement demonstrating imaging features of infection or inflammation in a young child with mild infectious symptoms and elevated inflammatory markers should invoke the possibility of an underlying K. kingae infection.

Arthritis in children: comparison of clinical and biological characteristics of septic arthritis and juvenile idiopathic arthritis

AIM

Childhood arthritis arises from several causes. The aim of this observational study is to compare the clinical and biological features and short-term outcome of different types of arthritis because they have different treatment and prognoses.

METHODS

Children <16 years of age hospitalised in a French tertiary care centre for a first episode of arthritis lasting for less than 6 weeks who underwent joint aspiration were retrospectively included. We performed non-parametrical tests to compare groups (septic arthritis (SA), juvenile idiopathic arthritis (JIA) and arthritis with no definitive diagnosis). The time before apyrexia or C reactive protein (CRP) <10 mg/L was analysed using the Kaplan-Meier method.

RESULTS

We studied 125 children with a sex ratio (M/F) of 1.1 and a median age of 2.2 years (range 0.3 to 14.6). SA was associated with a lower age at onset (1.5 years, IQR 1.2-3.0 vs 3.6 years, IQR 2.2-5.6), shorter duration of symptoms before diagnosis (2 days, IQR 1-4 vs 7 days, IQR 1-19) and higher synovial white blood cell count (147 cells ×10³/mm³, IQR 71-227, vs 51 cells ×10³/mm³, IQR 12-113), than JIA. Apyrexia occurred later in children with JIA (40% after 2 days, 95% CI 17% to 75%) than children with SA (82%, 95% CI 68% to 92%), as did CRP<10 mg/L (18% at 7 days, 95% CI 6.3% to 29.6% vs 82.1%, 95% CI 76.1% to 89.7%, p=0.01).

CONCLUSIONS

There were no sufficiently reliable predictors for differentiating between SA and JIA at onset. The outcomes were different; JIA should be considered in cases of poor disease evolution after antibiotic treatment and joint aspiration.

The Contemporary Microbiology and Rates of Concomitant Osteomyelitis in Acute Septic Arthritis

BACKGROUND

Septic arthritis (SA) and acute osteomyelitis (AO) are among the most common serious bacterial infections of childhood. Knowledge of the microbiology of SA is critical to treatment. Awareness of the presence of attendant AO is also important to guide clinical management. We sought to describe the current microbiology of SA in children and clinical features associated with coexisting AO.

MATERIALS AND METHODS

Patients with SA were identified from the infectious diseases consult service records from 2010 to 2014. Patients with penetrating/open trauma and orthopedic hardware in situ were excluded.

RESULTS

A total of 168 patients with SA were included. The most common causative organism was Staphylococcus aureus accounting for 47.7% of cases (29.1% were methicillin-susceptible S. aureus and 18.5% were methicillin-resistant S. aureus), followed by group A streptococcus (GAS, 8.9%). The proportion of cases due to GAS increased from 2011 to 2014 (3.3%-16.7%; P = 0.1). One hundred eight (64.3%) patients had concurrent AO. The presence of osteomyelitis was associated with older median age (5.9 vs. 2.4 years; P = 0.04), a longer duration of symptoms (5 vs. 2.5 days; P < 0.001), S. aureus (62.1% vs. 21.7%; P < 0.001), bacteremia (46.2% vs. 20.3%; P = 0.001), a longer duration of fever after admission (5 vs. 2 days; P < 0.001) and a longer length of stay (10 vs. 6 days; P < 0.001).

CONCLUSIONS

Methicillin-resistant S. aureus continues to be an important cause of SA though GAS may be increasing in frequency. The presence of concomitant osteomyelitis is higher than previously reported and associated with older age, a longer duration of symptoms and fever, bacteremia and S. aureus.

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.

[Treatment and progression of acute communautary osteoarticular infections in healthy children: A retrospective monocentric study of 64 patients]

INTRODUCTION

The prognosis of osteoarticular infections has improved over the past 20 years but it still remains potentially severe. The treatment of these infections has been simplified and shortened. In 2008, the Pediatric Infectious Disease Group (GPIP) established new therapeutic guidelines in order to standardize treatment in France. The aim of this study is to analyze practices in a Parisian hospital and assess the efficacy of this treatment in short and medium terms.

MATERIALS AND METHODS

This retrospective study focused on patients older than 3 months, without comorbidities, who were hospitalized for an acute osteoarticular infection in 2012 at Trousseau Hospital (Paris), with a follow-up of at least 4 weeks. The patients were selected from the hospital register.

RESULTS

The study included 64 patients of 156, who were admitted for examination with a diagnosis of acute osteoarticular infection, bacteriologically confirmed (29/64) or presumed on the basis of bacteriological evidence (35/64). The median age of the patients was 22 months. Of the patients, 78 % were febrile; 35 patients had arthritis (54.7 %), 21 osteomyelitis (32.8 %), seven osteoarthritis (10.9 %), and one spondylitis. Preferential localizations were the knees and hips; 61 % of arthritis cases were diagnosed with ultrasound, 54 % of osteomyelitis cases with scintigraphy. The two main microorganisms found were Kingella kingae (62.1 %) and Staphylococcus aureus (24.1 %). In 98 % of cases, patients were treated by cefamandole, with or without gentamicine, for a median duration of 3 days (1-10) intravenously, with oral relay by amoxicillin-clavulanic acid, for a total duration of 6 weeks, but in association with rifampicin in 40 % of cases without explanation. The median follow-up was 13 weeks, with a treatment success rate of 86 %.

CONCLUSION

The study of local practices showed us that the GPIP guidelines are not followed, with the duration of oral treatment being too long. The trend in therapy is toward short treatments of 10-20 days, with a shorter intravenous phase.

Detection of bacterial pathogens in synovial and pleural fluid with the FilmArray Blood Culture Identification System

We report the use of FilmArray Blood Culture Identification (BCID) multiplex PCR system for pathogen detection from a child with septic arthritis that Streptococcus pyogenes was identified directly from synovial fluid and a child with complicated pneumonia with pleural effusion that Streptococcus pneumoniae was identified from pleural fluid.