A Clinical Prediction Rule for Bacterial Musculoskeletal Infections in Children with Monoarthritis in Lyme Endemic Regions.

STUDY OBJECTIVE: Children with a bacterial musculoskeletal infection (MSKI) require prompt identification and treatment. In Lyme disease endemic areas, children with an MSKI can present similarly to those with Lyme arthritis. Our goal was to derive a clinical prediction rule to accurately identify children at a low risk for an MSKI. METHODS: We enrolled children with monoarthritis presenting to 1 of 6 Pedi Lyme Net centers and performed a procalcitonin (PCT) and a first-tier Lyme C6 enzyme immunoassay (EIA) test. Our primary outcome was an MSKI (septic arthritis, osteomyelitis, or pyomyositis). Using recursive partitioning with k-fold cross validation, we derived a clinical prediction rule to identify children at a low risk of an MSKI. We calculated the accuracy of our novel rule in a derivation cohort. RESULTS: Of the 735 children in the derivation cohort with an available research biosample, 39 (5%) had an MSKI (18 had septic arthritis, 20 had osteomyelitis, and 1 had pyomyositis), 260 (37%) had Lyme arthritis, and 436 (53%) had other inflammatory arthritis. Children with a PCT level of more than or equal to 0.50 ng/mL and those with a C-reactive protein (CRP) level of more than or equal to 0.6 mg/dL with a negative Lyme C6 EIA were classified as not low risk for an MSKI. Of the 451 (61%) children categorized as low risk, none had an MSKI (sensitivity 100%, 95% confidence interval 91.0% to 100%; specificity 74.2%, 95% confidence interval 70.5% to 77.6%). CONCLUSION: A novel clinical decision rule that includes PCT, CRP, and a first-tier Lyme EIA was highly sensitive for MSKIs. Although broader external validation is required, the application of this rule may safely reduce invasive testing, procedures, and treatment for low risk children.

Skin and Soft Tissue Infections in Persons Who Inject Drugs.

Persons who inject drugs are at high risk for skin and soft tissue infections. Infections range from simple abscesses and uncomplicated cellulitis to life-threatening and limb-threatening infections. These infections are predominantly caused by gram-positive organisms with Staphylococcus aureus, Streptococcus pyogenes, and other streptococcal species being most common. Although antimicrobial therapy has an important role in treatment of these infections, surgical incision, drainage, and debridement of devitalized tissue are primary. Strategies that decrease the frequency of injection drug use, needle sharing, use of contaminated equipment, and other risk behaviors may be effective in preventing these infections in persons who inject drugs.

Pyomyositis in the United States 2002-2014.

OBJECTIVES: Primary pyomyositis is a bacterial infection of skeletal muscle first recognized in tropical regions of the world but needing characterization in temperate climates. METHODS: This population-based study used the Healthcare Utilization Project/Nationwide Inpatient Sample database to characterize the trends of pyomyositis admissions in the United States from 2002-2014 using ICD-9 diagnostic codes. RESULTS: We found a concerning more than three-fold increase in the incident pyomyositis admissions over our study period. The median length of stay was over twice as long compared to other hospitalized patients. Patients with pyomyositis were younger and more likely to be male and Black. There were more cases in the West and South compared to Midwest and Northeast. Age-adjusted odds ratios revealed significant association of pyomyositis with HIV, types 1 and 2 diabetes mellitus, hematologic malignancy, organ transplant, malnutrition, chronic kidney disease, obesity, and rheumatoid arthritis. The most commonly identified bacterial diagnosis was Staphylococcus aureus. Pseudomonas species were the most commonly identified gram-negative bacteria. CONCLUSION: This nationwide review of pyomyositis in the United States suggests a concerning increase in incidence and provides information on the trends, demographics, risk factors, and causative organisms for pyomyositis in the United States.

Tropical pyomyositis: an update.

Tropical pyomyositis (TP) is a life-threatening bacterial infection of the skeletal muscle that occurs particularly among children, young adults and those with immunocompromised conditions. The appropriate diagnosis and treatment are often delayed due to its non-specific signs, leading to fatal consequences. Staphylococcus aureus, especially methicillin-susceptible S. aureus, is responsible for most TP cases. However, other bacteria (i.e. streptococci, Pseudomonas aeruginosa, Escherichia coli, Klebsiella spp., Candida spp., Mycobacterium spp.) have been reported. This narrative review provides an update on the epidemiology and clinical course of TP. A special focus is laid on the role of toxins (i.e. Panton-Valentine Leucocidin and α-toxin) in the pathogenesis of TP and their implication for the clinical management of infection.

La pyomyosite tropicale (TP) est une infection bactérienne potentiellement mortelle du muscle squelettique qui survient particulièrement chez les enfants, les jeunes adultes et les personnes immunodéprimées. Le diagnostic et le traitement appropriés sont souvent retardés en raison de ses signes non spécifiques, entraînant des conséquences fatales. Staphylococcus aureus, en particulier S. aureus sensible à la méthicilline, est responsable de la plupart des cas de TP. Cependant, d'autres bactéries (ex: streptocoques, Pseudomonas aeruginosa, Escherichia coli, Klebsiella spp., Candida spp., Mycobacterium spp.) ont été rapportées. Cette revue narrative fournit une mise à jour sur l'épidémiologie et l'évolution clinique du TP. Un accent particulier est mis sur le rôle des toxines (la Leukocidine de Panton-Valentine et l'α-toxine) dans la pathogenèse du TP et leur implication pour la prise en charge clinique de l'infection.

Pelvic pyomyositis in children: changing trends in occurrence and management.

AIMS: We present the largest series of paediatric pelvic pyomyositis from a temperate country, analyse the factors influencing long term prognosis and suggest a diagnostic protocol. MATERIALS AND METHOD: We included 41 patients diagnosed with primary paediatric pelvic pyomyositis between 1998 and 2016, in this study with a mean age of 7.5 years. Demographic, clinical, radiological and follow-up data were reviewed. Statistical analysis was performed to analyse the influence of early diagnosis and treatment on the final outcome. RESULTS: There was an increased occurrence of primary pelvic pyomyositis in the last two years. Of cases identified, 85% fulfilled Kocher's criteria for hip septic arthritis. The mean time to diagnosis was 2.8 ± 0.8 days. The most common muscle affected was obturator internus (65.85%) and multifocal involvement was common (46.34%). Early diagnosis and antibiotic treatment within seven days from the time of onset of symptoms was the only factor that influenced final outcome (p < 0.001). DISCUSSION AND CONCLUSION: Pyomyositis is no longer restricted to tropical countries. The time from onset of symptoms to start of antibiotic treatment influences the final outcome. Clinical examination and inflammatory markers have low specificity in distinguishing between pyomyositis, septic arthritis, osteomyelitis or other infections. MRI is more sensitive and can diagnose pyomyositis in its early stages. Every suspected case of septic arthritis of the hip should undergo an ultrasound. MRI scan may be performed if the ultrasound shows inconclusive evidence of an effusion. Early identification will facilitate early antibiotic treatment which will improve the final outcome. CLINICAL RELEVANCE: There is an increasing occurrence of this tropical disease in temperate countries. Early diagnosis with an MRI scan and early antibiotic use results in good outcomes.

A Novel Classification System Based on Dissemination of Musculoskeletal Infection is Predictive of Hospital Outcomes.

BACKGROUND: Musculoskeletal infections (MSKIs) are a common cause of pediatric hospitalization. Children affected by MSKI have highly variable hospital courses, which seem to depend on infection severity. Early stratification of infection severity would therefore help to maximize resource utilization and improve patient care. Currently, MSKIs are classified according to primary diagnoses such as osteomyelitis, pyomyositis, etc. These diagnoses, however, do not often occur in isolation and may differ widely in severity. On the basis of this, the authors propose a severity classification system that differentiates patients based on total infection burden and degree of dissemination. METHODS: The authors developed a classification system with operational definitions for MSKI severity based on the degree of dissemination. The operational definitions were applied retrospectively to a cohort of 202 pediatric patients with MSKI from a tertiary care children's hospital over a 5-year period (2008 to 2013). Hospital outcomes data [length of stay (LOS), number of surgeries, positive blood cultures, duration of antibiotics, intensive care unit LOS, number of days with fever, and number of imaging studies] were collected from the electronic medical record and compared between groups. RESULTS: Patients with greater infection dissemination were more likely to have worse hospital outcomes for LOS, number of surgeries performed, number of positive blood cultures, duration of antibiotics, intensive care unit LOS, number of days with fever, and number of imaging studies performed. Peak C-reactive protein, erythrocyte sedimentation rate, white blood cell count, and temperature were also higher in patients with more disseminated infection. CONCLUSIONS: The severity classification system for pediatric MSKI defined in this study correlates with hospital outcomes and markers of inflammatory response. The advantage of this classification system is that it is applicable to different types of MSKI and represents a potentially complementary system to the previous practice of differentiating MSKI based on primary diagnosis. Early identification of disease severity in children with MSKI has the potential to enhance hospital outcomes through more efficient resource utilization and improved patient care. LEVEL OF EVIDENCE: Level II-prognostic study.

Piomiositis en un entorno no tropical. Casuística de 12 años / Pyomyositis in a non-tropical area. 12 years of cased-based experience

No disponible

Pyomyositis: Are We Missing the Diagnosis?

BACKGROUND: Pyomyositis (PY) is a primary infection of the skeletal muscles, leading to inflammation of the muscle fibers followed by pus formation and even necrosis in late stages. Because of overlap in presentation of intermuscular abscess (IM) and PY, the exact incidence and severity of PY is under-appreciated. PATIENTS AND METHODS: We conducted a prospective analytical study in a tertiary care center in North India from October 2011 to January 2013, recruiting patients with abscesses involving the chest wall, abdomen (parietal wall including back), and extremities. Subcutaneous, hepatic, intra-abdominal abscess, and secondary abscesses were excluded. Primary PY was defined as a primary infection of skeletal muscle without any foci from adjacent skin, soft tissue, or bone. Clinical, radiologic, pathologic, and operative findings suggested diagnosis; loss of striations and lymphocytic infiltration in the muscle fibers was confirmatory. The chief outcome variables were death and length of hospital stay. RESULTS: Thirty patients with a mean age of 29.5 y (IM: 29.7 ± 16.7, PY: 25.28 ± 17.6) were classified as IM (18/30, 60%) or PY (12/30, 40%). Most PY occurred in the lower limb (41.7% had multi-site involvement); most had a history of trauma or immunocompromised state. Fever, tachycardia, tachypnea, hypotension, pallor, and hyperesthesia were significantly higher (p < 0.05) in PY. Mean Sequential Organ Failure Assessment (SOFA) score was 0.33 for IM, 2.5 for PY. Staphylococcus aureus was predominant in both groups; however, all four patients with methicillin-resistant S. aureus (MRSA) were in the PY group. Both deaths also occurred in the PY group. The mean duration of hospital stay was 3.22 ± 1.11 d for IM and 10.27 ± 2.32 d for PY patients (p = 0.03). CONCLUSION: PY is a specific and potentially fatal infection, which is common in our country and must be differentiated from IM. A high index of suspicion and early institution of specific antibiotics followed by operation is therapeutic.

Sequential Parenteral to Oral Clindamycin Dosing in Pediatric Musculoskeletal Infection: A Retrospective Review of 30 mg/kg/d Versus 40 mg/kg/d.

BACKGROUND: Children with musculoskeletal infection in methicillin-resistant Staphylococcus aureus (MRSA) prevalent communities are often treated with oral clindamycin. Current guidelines recommend approximately 40 mg/kg/d for MRSA infections. This study investigates the clinical practice of using 30 mg/kg/d of clindamycin as an alternative for outpatient dosing. METHODS: Children with musculoskeletal infection treated with outpatient clindamycin from 2009 to 2014 were studied by retrospective review. The amount of clindamycin administered was determined from dose, interval and duration of outpatient treatment. Hospital readmission, surgeries and sequelae were assessed. Severity of illness was determined for children with osteomyelitis. The readmission rate of 25 children treated with 40 mg/kg/d was compared with that of 190 children treated with 30 mg/kg/d. The reason for readmission was evaluated to consider whether antibiotic dosing strategy was a potential factor. RESULTS: Among 215 children studied, the average outpatient duration of treatment was 32.8 days. There was no significant difference in the rate of readmission between dosing cohorts. Severity of illness scores (0-10 scale) was significantly higher among readmitted children with osteomyelitis (mean 9.8 ± 0.4) than among those with osteomyelitis who were not readmitted (mean 2.9 ± 3.2), P = 0.001. Sequelae were more common in the high-dose group and were noted in 3 children (12%) in that cohort compared with 6 children (3.2%) in the low-dose cohort (P > 0.05). CONCLUSION: Oral dosing of 30 mg/kg/d was effective for musculoskeletal infection in children in an MRSA prevalent community. Illness severity appeared to have greater impact on readmission and sequelae than did antibiotic dosing.

Piomiositis por Escherichia coli en un paciente en tratamiento crónico con glucocorticoides / Pyomiositis caused by Escherichia coli in a patient on chronic glucocorticoid treatment

No disponible

Increasing pyomyositis presentations among children in Queensland, Australia.

BACKGROUND: Pyomyositis, usually associated with tropical climates, occurs less commonly in temperate regions and is most often caused by Staphylococcus aureus. Several community-acquired methicillin-resistant S. aureus (CA-MRSA) clones have emerged in Queensland since the beginning of the century, and they now account for a significant proportion of invasive staphylococcal infection. This study aims to describe trends in the rate of presentation, and the clinical and diagnostic features of pyomyositis, and to determine if trends are attributed to the emergence of CA-MRSA or other factors. METHODS: A 10-year retrospective cohort study of all patients presenting to Mater Children's Hospital in Brisbane, Queensland, with pyomyositis between July 2002 and July 2012, was conducted. Data were collected for clinical features, microbiology, diagnostic tests, management and outcome. Trends in incidence, and clinical and diagnostic features of pyomyositis were analyzed. RESULTS: Thirty-four cases of pyomyositis were identified. There was a male predominance (79%), and the vertebro-pelvic muscles were most often affected. The rate of pyomyositis increased significantly during the study period from a rate of 2.04 cases per 10,000 emergency department admissions in the first quarter of the study, to 8.73 cases per 10,000 in the final quarter (peak rate 13.5 cases per 10,000 in 2008). A causative organism was identified in 22 cases, most commonly methicillin-susceptible S. aureus with CA-MRSA identified in 4 cases. Patients who required surgical intervention had longer hospital admission, longer time to resolution of inflammatory markers and a higher risk of complication at follow-up. CONCLUSION: This study demonstrates an increasing incidence of pyomyositis in a temperate region, which is not attributable to the emergence of CA-MRSA. The reasons for this change in incidence are not clear.

Temperate pyomyositis: a pain in the belly.

Pyomyositis is a rare disease in temperate climates. This case is a unique presentation of pyomyositis of the rectus abdominal muscle mimicking an acute abdominal process. Most reported cases of pyomyositis are of extremity infections with Staphylococcus aureus.This report presents a case of polymicrobial pyomyositis from Haemophylus parainfluenza and Steptococcus viridians infection.

Epidemiology, diagnosis, and treatment of pericapsular pyomyositis of the hip in children.

BACKGROUND: The yield of synovial fluid cultures in patients meeting clinical criteria for septic hip arthritis remains low. In the presence of positive blood cultures, these patients are diagnosed and treated as "presumed septic arthritis." We hypothesized that some of these patients may instead have an extra-articular infection, such as pericapsular pyomyositis. METHODS: An IRB-approved prospective study of children with suspected septic hip arthritis at a tertiary care children's hospital over a 2-year time period was conducted. Children were evaluated with a previously published clinical algorithm with the addition of magnetic resonance imaging (MRI). RESULTS: Of the 53 patients presenting with an acutely irritable hip, 32% were found to have pericapsular pyomyositis, whereas 15% were diagnosed with septic arthritis. Although C-reactive protein (CRP, ≥33.1 mg/L) performed well at predicting infection, there were no significant differences in CRP, erythrocyte sedimentation rate, white blood cell count, temperature, or weight-bearing status in children with septic arthritis compared with pericapsular pyomyositis. In addition to MRI, there was a difference in the size of hip effusion on ultrasound, which was significantly smaller in cases of pericapsular pyomyositis. CRP (≥74.3 mg/L) was found to be predictive of need for surgical intervention in children with pericapsular pyomyositis. CONCLUSIONS: Correct anatomic diagnosis of the site of infection is essential for the efficient care of the child. Herein, we found that pericapsular pyomyositis is twice as common as septic arthritis in children presenting with an acutely irritable hip. Clinical algorithms are incapable of differentiating these pathologies suggesting that both be considered under the current diagnosis previously referred to as "presumed septic arthritis." Incorrect diagnosis of a septic arthritis in the presence of a pericapsular pyomyositis could potentially lead to unnecessary debridement of the joint in the presence of extra-articular infection, thus contaminating the joint. Conversely, debriding the joint instead of the epicenter of the infection can prolong the infectious process. For these reasons, we conclude that MRI has the potential to improve the clinical care of children by providing a more precise diagnosis. LEVEL OF EVIDENCE: Level II-"Diagnostic" [Development of diagnostic criteria on the basis of consecutive patients (with universally applied reference "gold" standard)].

Hip septic arthritis and other pediatric musculoskeletal infections in the era of methicillin-resistant Staphylococcus aureus.

Pediatric musculoskeletal infections can cause devastating complications (including death) in this era of methicillin-resistant Staphylococcus aureus and other virulent bacterial strains. The complexity and severity of these infections require timely diagnosis and treatment. A thorough emergency department evaluation, diagnostic workup, and early surgical intervention can influence outcomes. Septic arthritis of the hip is best treated with open drainage and antibiotic therapy to avoid osteonecrosis of the hip and joint damage. Because of genetic changes and inducible resistance, methicillin-resistant Staphylococcus aureus causes more complex infections than in the past. Deep, soft-tissue abscesses; pyomyositis; osteomyelitis; and septic arthritis often occur concurrently, causing destruction of musculoskeletal tissue. Severe and life-threatening complications, such as septic emboli, deep venous thrombosis, and multiorgan system failure may result from these infections.

Staphylococcus aureus causing tropical pyomyositis, Amazon Basin, Peru.

We studied 12 Staphylococcus aureus isolates causing tropical pyomyositis in the Amazon Basin of Peru. All isolates were methicillin-susceptible; 11 carried Panton-Valentine leukocidin-encoding genes, and 5 belonged to multilocus sequence type 25 and possessed an extensive set of enterotoxins. Our findings suggest sequence type 25 is circulating in tropical areas of South America.

Pyomyositis in the upper Negro river basin, Brazilian Amazonia.

Pyomyositis remains poorly documented in tropical Latin America. We therefore performed a retrospective review of cases admitted to a hospital in the upper Negro river basin during 2002-2006. Seasonality was assessed by the cosinor model and independent predictors of outcome were identified by logistic regression. Determinants of time-to-fever resolution were analysed using Cox regression. No seasonal trend was observed (p=0.284) among 82 hospitalised patients. The disease predominated in young males and the most commonly affected part of the body was the lower limb (68 [63.5%] out of 107 lesions). Staphylococcus aureus was the only identified infecting organism (18 of 20 culture results, 90%). Complications occurred in 17 patients (20.7%) and the case fatality rate was 2.4%. Children were more likely to present with eosinophilia than adults (OR= 4.20, 95% CI 1.08-16.32, p=0.048), but no other significant differences regarding clinical presentation and outcomes were observed. The time-to-fever resolution was the only independent determinant of poor outcome (OR=1.52, 95% CI 1.22-1.92, p<0.001) and was significantly longer in patients treated with combined antibiotic therapy than in those treated with single antibiotics (HR=0.523, 95% CI 0.296-0.926, p=0.026). Further studies to determine the best antibiotic therapy modality for the treatment of pyomyositis are required.

Draft genome sequence of Staphylococcus aureus 118 (ST772), a major disease clone from India.

We report the draft genome sequence of an ST772 Staphylococcus aureus disease isolate carrying staphylococcal cassette chromosome mec (SCCmec) type V from a pyomyositis patient. Our de novo short read assembly is ∼2.8 Mb and encodes a unique Panton-Valentine leukocidin (PVL) phage with structural genes similar to those of ϕ7247PVL and novel lysogenic genes at the N termini.

Surgical aspects of bacterial infection in African children.

Infections and their complications requiring surgical intervention are a frequent presentation in African children. Surgical site infection (SSI) is common with rates over 20%, even after clean procedures. The high rates of SSI are due in part to lack of infection control and surveillance policies in most hospitals in Africa. SSI is attended by complications, long hospital stay, and some mortality, but the economic consequences are unestimated. Typhoid fever and typhoid intestinal perforation are major problems with perforation rates of approximately 10%, which is higher in older children. The ideal surgical treatment is arguable, but simple closure and segmental resection are the present effective surgical options. Because of delayed presentation, complications after surgical treatment are high with a mortality approaching 41% in some parts of Africa. Nutrition for these patients remains a challenge. Acute appendicitis, although not as common in African children, often presents rather late with up to 50% of children presenting with perforation and other complications, and mortality is approximately 4% is some settings. Pyomyositis and necrotizing fasciitis are the more common serious soft-tissue infections, but early recognition and prompt treatment should minimize the occasional mortality. Though common in Africa, the exact impact of human immunodeficiency virus infection on the spectrum and severity of surgical infection in African children is not clear, but it may well worsen the course of infection in these patients.

Staphylococcus aureus pyomyositis compared with non-Staphylococcus aureus pyomyositis.

OBJECTIVES: Pyomyositis is an acute bacterial infection of skeletal muscle not arising from contiguous infection. It is often hematogenous in origin and typically associated with abscess formation. Our objective was to determine if there were any differences in the clinical presentation of disease between Staphylococcus aureus (SA) and non-Staphylococcus aureus pyomyositis. We also sought to determine if methicillin-resistant SA (MRSA) occurred more frequently during the final years of the study period. METHODS: A retrospective chart review study at three institutions in two cities. RESULTS: Sixty cases of pyomyositis were identified between 1990 and 2010. Twenty-nine patients were infected with SA while 31 had other bacterial etiologies or were culture negative. Those with a traumatic event prior to the onset of infection were more likely to have a SA infection while SA infected patients were younger. Our first documented case of MRSA occurred in 2005, but the frequency of MRSA infection remained static over the following five years. CONCLUSIONS: Pyomyositis is an emerging infection that is underappreciated by many physicians. While MRSA has emerged as the foremost cause of SA infections in a majority of clinical conditions, in this series most patients still had methicillin-sensitive SA as their cause of pyomyositis. In light of the severity of pyomyositis and the potential for bacteremia (either as a source or complication of the infection), empiric SA therapy should be initiated in all patients until the culture results are available.

Tropical pyomyositis and necrotizing fasciitis.

Pyomyositis is a purulent infection of skeletal muscle that arises from hematogenous spread, usually with abscess formation. Necrotizing fasciitis is a more severe, rapidly progressive infection involving the superficial and deep fascia with necrosis and fluid collections that can be life threatening if left untreated. Both conditions may coexist, and concomitant cellulitis is often seen. A high incidence of these diseases occurs in the tropics, but they are increasingly being seen in temperate countries, due in part to their association with immunodeficiency conditions such as human immunodeficiency virus (HIV) infection, diabetes mellitus, and organ transplantation. This article aims to familiarize physicians with these entities, review their clinical manifestations and imaging features, and highlight the role of imaging in the management of patients with these conditions.