Management and outcome of children with skin and soft tissue abscesses caused by community-acquired methicillin-resistant Staphylococcus aureus

Purulent Skin and Soft Tissue Infections, Challenging the Practice of Incision and Drainage: A Scoping Review

Aim

To generate a landscape of the current knowledge in the interventional management and outcomes of purulent skin and soft tissue infections.

Design

This study is a scoping review.

Methods

Electronic searches were undertaken using CINAHL, Medline, Cochrane Library, British Nursing Index, Science Direct, the National Health Service knowledge and library hub, ClinicalTrials.gov, and MedNar. The population, concept, context framework, and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews were utilised, supporting a rigorous appraisal and synthesis of literature. Data Sources. The initial search and synthesis of literature were completed in January 2022 with repeat searches completed in March 2022 and July 2023. There were no imposed chronological parameters placed on the returned literature.

Results

Nineteen papers were reviewed. Incision and drainage with primary closure, needle aspiration, loop drainage, catheter drainage, and suction drainage are viable adjuncts or alternatives to the traditional surgical management of skin and soft tissue abscesses.

Conclusion

Despite the empirically favourable alternatives to the incision and drainage technique demonstrated, this does not appear to be driving a change in clinical practice. Future research must now look to mixed and qualitative evidence to understand the causative mechanisms of incision and drainage and its ritualistic practice. Implications. Ritual surgical practices must be challenged if nurses are to improve the treatment and management of this patient group. This will lead to further practice innovation. Impact: This study explored the challenges posed to patients, clinicians, nurses, and stakeholders, resulting from the ritualistic practice of the incision and drainage technique in purulent skin or soft tissue abscesses. Empirically and holistically viable alternatives were identified, impacting all identified entities and recommending a wider holistic study. Reporting Method. Adherence to EQUATOR guidance was achieved through the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews.

Advanced finger infection: more frequent than expected and mostly iatrogenic

Some patients present at an advanced stage of their fingertip infection with an extension of the infection in anatomical spaces or into fragile structures. One hundred and twenty-five patients have been operated on for a finger infection. Forty-one patients (33%) have been treated at the "complication" stage, while 84 cases (67%) were considered "non-complicated". The delay between initial injury and the surgical treatment was 12 days in the "non-complicated" group versus 30 in the "complication" group (p < 0.001). Osteitis (39% of the complications), and flexor sheath infection (37%) were the most frequent complications. Prescribing preoperative antibiotics increases the risk of being in the "complicated" group at p = 0.09. One hundred and thirteen patients (90.4%) were cured of their infection after a single operation. Neither the cause of infection, nor the type of germ or associated diabetes increased the risk of complication in our series. A better education of the first interveners (general practitioner or emergency doctor) in hand infection care could reduce the rate of complication allowing a faster access to hand surgeons.

Loop Drainage Is Noninferior to Traditional Incision and Drainage of Cutaneous Abscesses in the Emergency Department

BACKGROUND

There is limited research on loop drainage (LD) compared to incision and drainage (I&D) for treatment of cutaneous abscesses. We investigated whether LD was noninferior to I&D for abscess resolution and whether there was any difference in repeat ED visits or complication rates between these techniques.

METHODS

We performed a prospective randomized controlled trial, using a convenience sample at an urban academic emergency department (ED). Subjects over 18 years who presented for first-time management of an abscess were eligible. Patients requiring specialist drainage or hospital admission or had previous treatment for the abscess were excluded. Enrolled subjects were seen 2 weeks after treatment for blinded reevaluation of abscess resolution, and the electronic medical record was reviewed for return ED visits/abscess complications.

RESULTS

Of 2,889 patients screened, 238 subjects consented and were randomized to LD or I&D. Abscess resolution was achieved in 53/65 (81.5%) of patients in the I&D arm, compared to 66/75 (88%) in the LD arm. Fewer patients in the LD group compared to the I&D group returned to the ED for abscess-related management during the following 14 days (37.3% vs 67.1%, p = 0.002). Among returning subjects, there was a significant difference in mean visits per subject between LD and I&D groups (0.5 vs. 1.2, p = 0.001). There were fewer complications among LD than I&D subjects (9.3% vs. 24.6%, p = 0.01).

CONCLUSION

Our study provides evidence that LD is noninferior to I&D in achieving complete abscess resolution at 14 days and is associated with fewer return ED visits and fewer complications. This makes it an attractive alternative treatment option for abscesses.

Intersection of HIV and community-associated methicillin-resistant Staphylococcus aureus

The epidemiology of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has evolved over the past approximately 20 years, with certain populations appearing to have disproportionate risk. Of concern is the potential worsening of S. aureus infections in light of the continued opioid crisis. This review will discuss how CA-MRSA has significantly impacted HIV-infected individuals and address additional factors and populations that are associated with increased risk for MRSA. It will review therapeutic options and infection control strategies as well as highlight how whole genome sequencing can be used to extend traditional epidemiologic analysis and ultimately, inform infection prevention efforts. Continued work identifying those at the highest risk for MRSA, what the best infection prevention settings are in community settings and how to effectively implement and target these strategies is needed. Ultimately, infection control efforts will likely need to extend beyond healthcare settings to effectively and sustainably reduce MRSA infections.

Prospective observational study to assess the need for postoperative antibiotics following surgical incision and drainage of skin and soft tissue abscess in pediatric patients

BACKGROUND

Post-operative antibiotics are often utilized for skin and soft tissue infection (SSTI) requiring surgical incision and drainage (I&D). We propose that antibiotics are unnecessary following I&D.

METHODS

Patients aged 3months to 6years with SSTI of the buttocks, groin, thigh, and/or labia requiring I&D were prospectively enrolled. The primary outcome was the proportion of patients requiring re-drainage and/or antibiotics for SSTI recurrence, within 30days. Follow-up consisted of a 30-day phone call, with optional 2-week office visit, combined with chart review for patients lost to follow-up. A one-sample binomial proportion with 95% confidence interval (CI) was used to examine non-inferiority for rate of treatment success, using previously published success rates for patients receiving antibiotics post-operatively (95.9%, with a 7% margin of equivalence).

RESULTS

A total of 92 patients were enrolled. All patients received pre-operative antibiotics. There was one treatment failure (success rate 0.989, CI 0.941-0.999). The recurrence rate was noninferior to previously-published data for patients receiving postoperative antibiotics (p<0.001). Subgroup analysis of patients who completed 30-day follow-up yielded a success rate of 0.973, CI 0.858-0.999 and evidence of non-inferiority (p=0.04).

CONCLUSIONS

Post-operative management excluding antibiotics should be considered for patients who undergo I&D for SSTI.

LEVEL OF EVIDENCE

Level II (prospective cohort study with <80% follow-up).

Comparative Study of Drainage and Antibiotics versus Drainage Only in the Management of Primary Subcutaneous Abscesses

BACKGROUND

Skin and soft tissue infections are common problems dealt with in emergency departments and medical offices. It is routine practice to prescribe antibiotic agents after incision and drainage of cutaneous abscesses. However, current evidence does not support prescribing oral antibiotic agents after surgical debridement. The aim of the present study was to determine the actual role of antibiotic agents after drainage of cutaneous abscesses.

PATIENTS AND METHODS

This was a prospective study of patients undergoing incision and drainage (I&D) of a subcutaneous abscess. Patients were randomly assigned either to receive antibiotic agents (group 1) or placebo (group 2) after I&D. The primary end point was resolution rate of the abscess at the seventh day. Secondary end points were pain at the seventh day and total time to full healing of the wound. P value <0.05 was considered statistically significant.

RESULTS

One hundred sixty-five patients were included for analysis. Age, gender, body mass index (BMI), and comorbidities did not differ substantially between groups. Chest and peri-anal abscesses were statistically more frequent in group 2, whereas neck abscesses were more frequent in group 1 (p = 0.02). Leukocyte count was also statistically higher in group 1 (p = 0.005). Resolution rate was 96% in group 1 and 93% in group 2, with no statistical difference between both (p = 0.28). Neither pain at seventh day nor time to full healing differed statistically between groups.

CONCLUSIONS

Antibiotic agents are not necessary for uncomplicated subcutaneous abscesses after I&D. These cases can be managed safely on an outpatient basis without any increase in morbidity.

Teaching Incision and Drainage: Perceived Educational Value of Abscess Models

OBJECTIVES

Incision and drainage (I&D) of skin abscesses is an important procedural skill for pediatric emergency medicine providers. Practical skills training using simulation provides an opportunity to learn and gain confidence with this invasive procedure. Our objective was to assess the perceived educational value of 2 versions of an abscess model as part of an educational workshop for teaching I&D.

METHODS

A combined didactic and practical skills workshop was developed for use at 2 national conferences. The didactic content was created through an iterative process. To facilitate hands-on training, 2 versions of an abscess model were created: 1 constructed from a negative mold and the other using a 3-dimensional printer. Participants were surveyed regarding prior experience with I&D, procedural confidence, and perceptions of the educational utility of the models.

RESULTS

Seventy physicians and 75 nurse practitioners participated in the study. Procedural confidence improved after training using each version of the model, with the greatest improvements noted among novice learners. Ninety-four percent of physicians, and 99% of nurse practitioners rated the respective models as either "educational" or "very educational," and 97% and 100%, respectively, would recommend the abscess models to others.

CONCLUSIONS

A combined didactic and practical skills educational workshop using novel abscess models was effective at improving learners' confidence. Our novel models provide an effective strategy for teaching procedural skills such as I&D and demonstrate a novel use of 3-dimensional printers in medical education. Further study is needed to determine if these educational gains translate into improvement in clinical performance or patient outcomes.

Ultrasound-Guided Drainage for Pediatric Soft Tissue Abscesses Decreases Clinical Failure Rates Compared to Drainage Without Ultrasound: A Retrospective Study

OBJECTIVES

Soft tissue abscesses are common in the pediatric emergency department (ED). Ultrasound (US) can be used to both diagnose soft tissue abscesses as well as guide drainage. We hypothesized that clinical failure rates would be less in pediatric patients with suspected skin abscesses when evaluated with US.

METHODS

We performed a retrospective review of suspected pediatric skin abscesses at 4 EDs over a 22-month period. Cases were identified through electronic medical record descriptions, discharge diagnoses, and US database records. Data on US use, findings, and outcomes were abstracted to an electronic database. Comparisons between groups included US versus non-US (primary outcome) as well as surgical drainage vs nonsurgical drainage (secondary outcome).

RESULTS

A total of 377 patients were seen with concern for a potential skin abscess; 141 patients (37.4%) underwent US imaging during their visit, and 239 (63.4%) underwent incision and drainage (I&D) during their ED stay: 90 with US and 149 without. The failure rate for patients evaluated with US was significantly lower than that for those evaluated without US (4.4% versus 15.6%; P < .005). Thirty-four (11.3%) of the 302 patients with a diagnosis of an abscess failed therapy: 19 (8.2%) after I&D and 15 (21.1%) after nonsurgical management. Failure after I&D was associated with a smaller abscess cavity on US imaging (17.2 versus 44.8 mm³ ; P < .05).

CONCLUSIONS

The use of US for patients with a suspected skin abscess was associated with a reduction in the amount of clinical failure rates after both surgical drainage and nonsurgical therapy. Ultrasound should be used when evaluating or treating patients with abscesses.

Clinical Presentation of Soft-tissue Infections and its Management: A Study of 100 Cases

BACKGROUND

Soft-tissue infections vary widely in their nature and severity. A clear approach to the management must allow their rapid identification and treatment as they can be life-threatening.

OBJECTIVE

Clinical presentation of soft-tissue infections and its management.

MATERIALS AND METHODS

A prospective study based on 100 patients presenting with soft-tissue infections was done. All the cases of soft-tissue infections were considered irrespective of age, sex, etiological factors, or systemic disorders. The findings were evaluated regarding the pattern of soft-tissue infections in relation to age and sex, clinical presentation, complications, duration of hospital stay, management, and mortality.

RESULTS

The most commonly involved age group was in the range of 41-60 years with male predominance. Abscess formation (45%) was the most common clinical presentation. Type 2 diabetes mellitus was the most common associated comorbid condition. Staphylococcus aureus was the most common culture isolate obtained. The most common complication seen was renal failure. Patients with surgical site infections had maximum duration of stay in the hospital. About 94% of the cases of soft-tissue infections were managed surgically. Mortality was mostly encountered in the cases of complications of cellulitis.

CONCLUSION

Skin and soft-tissue infections are among the most common infections encountered by the emergency physicians. Ignorance, reluctance to treatment, economic constraints, and illiteracy delay the early detection and the initiation of proper treatment. Adequate and timely surgical intervention in most of the cases is of utmost importance to prevent the complications and reduce the mortality.

Subgroup Analysis of Antibiotic Treatment for Skin Abscesses

STUDY OBJECTIVE

Two large randomized trials recently demonstrated efficacy of methicillin-resistant Staphylococcus aureus (MRSA)-active antibiotics for drained skin abscesses. We determine whether outcome advantages observed in one trial exist across lesion sizes and among subgroups with and without guideline-recommended antibiotic indications.

METHODS

We conducted a planned subgroup analysis of a double-blind, randomized trial at 5 US emergency departments, demonstrating superiority of trimethoprim-sulfamethoxazole (320/1,600 mg twice daily for 7 days) compared with placebo for patients older than 12 years with a drained skin abscess. We determined between-group differences in rates of clinical (no new antibiotics) and composite cure (no new antibiotics or drainage) through 7 to 14 and 42 to 56 days after treatment among subgroups with and without abscess cavity or erythema diameter greater than or equal to 5 cm, history of MRSA, fever, diabetes, and comorbidities. We also evaluated treatment effect by lesion size and culture result.

RESULTS

Among 1,057 mostly adult participants, median abscess cavity and erythema diameters were 2.5 cm (range 0.1 to 16.0 cm) and 6.5 cm (range 1.0 to 38.5), respectively; 44.3% grew MRSA. Overall, for trimethoprim-sulfamethoxazole and placebo groups, clinical cure rate at 7 to 14 days was 92.9% and 85.7%; composite cure rate at 7 to 14 days was 86.5% and 74.3%, and at 42 to 56 days, it was 82.4% and 70.2%. For all outcomes, across lesion sizes and among subgroups with and without guideline antibiotic criteria, trimethoprim-sulfamethoxazole was associated with improved outcomes. Treatment effect was greatest with history of MRSA infection, fever, and positive MRSA culture.

CONCLUSION

Treatment with trimethoprim-sulfamethoxazole was associated with improved outcomes regardless of lesion size or guideline antibiotic criteria.

Treatment of subcutaneous abscesses in children with incision and loop drainage: A simplified method of care

PURPOSE

The aim of this study was to expand on our previous report of 115 patients after more than a decade-long experience using incision and loop drainage for pediatric subcutaneous abscess management. This report comprises the largest consecutive series of pediatric abscess patients from a single institution ever recorded.

METHODS

A retrospective study was performed of all pediatric patients who underwent incision and loop drainage of subcutaneous abscesses at our institution between January 2002 and December 2014.

TECHNIQUE

Two sub 5mm incisions were made at the periphery on the abscess. The abscess cavity was probed to break down loculations and drain pus. The abscess cavity was irrigated with normal saline. A loop drain was passed through one incision and brought out through the other. A simple absorbent dressing was applied over the drain.

RESULTS

Five hundred seventy-six consecutive patients underwent loop drainage procedures. Mean values are as follows: age, 3.84years; duration of symptoms, 6.17days; postoperative length of stay (with 4 outliers excluded), 0.69days; drain duration, 8.38days; and number of postoperative visits, 1.28. Twenty-six patients had reoperations (4.5%), 2 of which were planned staged excisions of pilonidal cysts and 1 because of accidental home removal.

CONCLUSIONS

Micro-incisions and loop drainage is a safe and effective treatment modality for subcutaneous abscesses in children. The findings eliminate the need for repetitive wound packing and simplify postoperative wound care. Loop drainage offers shorter time to discharge, lower recurrence rates, and minimal scarring. Additionally, there is expected cost reduction. We recommend this minimally invasive procedure to be the standard of care for subcutaneous abscesses in children.

TYPE OF STUDY

Treatment study - retrospective review.

LEVEL OF EVIDENCE

Level IV - case series with no comparison group.

A Placebo-Controlled Trial of Antibiotics for Smaller Skin Abscesses

BACKGROUND

Uncomplicated skin abscesses are common, yet the appropriate management of the condition in the era of community-associated methicillin-resistant Staphylococcus aureus (MRSA) is unclear.

METHODS

We conducted a multicenter, prospective, double-blind trial involving outpatient adults and children. Patients were stratified according to the presence of a surgically drainable abscess, abscess size, the number of sites of skin infection, and the presence of nonpurulent cellulitis. Participants with a skin abscess 5 cm or smaller in diameter were enrolled. After abscess incision and drainage, participants were randomly assigned to receive clindamycin, trimethoprim-sulfamethoxazole (TMP-SMX), or placebo for 10 days. The primary outcome was clinical cure 7 to 10 days after the end of treatment.

RESULTS

We enrolled 786 participants: 505 (64.2%) were adults and 281 (35.8%) were children. A total of 448 (57.0%) of the participants were male. S. aureus was isolated from 527 participants (67.0%), and MRSA was isolated from 388 (49.4%). Ten days after therapy in the intention-to-treat population, the cure rate among participants in the clindamycin group was similar to that in the TMP-SMX group (221 of 266 participants [83.1%] and 215 of 263 participants [81.7%], respectively; P=0.73), and the cure rate in each active-treatment group was higher than that in the placebo group (177 of 257 participants [68.9%], P<0.001 for both comparisons). The results in the population of patients who could be evaluated were similar. This beneficial effect was restricted to participants with S. aureus infection. Among the participants who were initially cured, new infections at 1 month of follow-up were less common in the clindamycin group (15 of 221, 6.8%) than in the TMP-SMX group (29 of 215 [13.5%], P=0.03) or the placebo group (22 of 177 [12.4%], P=0.06). Adverse events were more frequent with clindamycin (58 of 265 [21.9%]) than with TMP-SMX (29 of 261 [11.1%]) or placebo (32 of 255 [12.5%]); all adverse events resolved without sequelae. One participant who received TMP-SMX had a hypersensitivity reaction.

CONCLUSIONS

As compared with incision and drainage alone, clindamycin or TMP-SMX in conjunction with incision and drainage improves short-term outcomes in patients who have a simple abscess. This benefit must be weighed against the known side-effect profile of these antimicrobials. (Funded by the National Institutes of Health; ClinicalTrials.gov number, NCT00730028 .).

Characterization of Community-Acquired Staphylococcus aureus Infections in Children

Background:

Limited data exist concerning characteristics of community-acquired Staphylococcus aureus infections (CA-SAI) in central and eastern Kentucky.

Objective:

To describe the incidence of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infections from January 1, 2004 through December 31, 2005, compare the number of CA-MRSA infections between years, and contrast treatment interventions and antibiotic susceptibility patterns of CA-SAI.

Methods:

A concurrent and retrospective study was conducted in 125 patients less than 18 years of age with CA-SAI admitted to the hospital/clinic based on criteria from the Centers for Disease Control and Prevention. Data on demographics, length of stay, antibiotic therapy, and antibiotic susceptibilities were collected.

Results:

Seventy patients were included for analysis (CA-MRSA, n = 51; community-acquired methicillin-susceptible S. aureus [CA-MSSA], n = 19). No statistically significant differences were noted between the number of CA-MRSA infections and the total CA-SAI (9/15 in 2004 vs 42/55 in 2005; p = 0.15). Approximately 75% of patients with CA-SAI were admitted to the hospital with no significant difference in length of stay. Ninety percent of CA-SAI were skin and soft tissue infections. There was a significant difference between groups with cutaneous abscesses (CA-MRSA, n = 37 vs CA-MSSA, n = 6; p = 0.002). Greater than 95% of all isolates were susceptible to vancomycin and trimethoprim/sulfamethoxazole. Half of CA-MRSA patients received inappropriate antibiotic therapy with β-lactam antibiotics or clindamycin without confirmatory disk diffusion test. Twenty-five (49%) patients with CA-MRSA received surgical debridement (S/D) and/or incision and drainage (I/D) with concomitant antibiotic therapy. Four patients with CA-MRSA were rehospitalized for subsequent infections; all 4 received appropriate antibiotic therapy.

Conclusions:

A noticeable increase in CA-MRSA infections with cutaneous abscess between 2004 and 2005 was noted. In patients receiving inappropriate antibiotic therapy, treatment success was attributed to concomitant S/D and I/D. Further analysis should focus on the impact of antibiotic therapy alone or in combination with S/D and I/D on the incidence of subsequent CA-MRSA infections.

A prospective observational cohort study in primary care practices to identify factors associated with treatment failure in Staphylococcus aureus skin and soft tissue infections

Background

The incidence of outpatient visits for skin and soft tissue infections (SSTIs) has substantially increased over the last decade. The emergence of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has made the management of S. aureus SSTIs complex and challenging. The objective of this study was to identify risk factors contributing to treatment failures associated with community-associated S. aureus skin and soft tissue infections SSTIs.

Methods

This was a prospective, observational study among 14 primary care clinics within the South Texas Ambulatory Research Network. The primary outcome was treatment failure within 90 days of the initial visit. Univariate associations between the explanatory variables and treatment failure were examined. A generalized linear mixed-effect model was developed to identify independent risk factors associated with treatment failure.

Results

Overall, 21% (22/106) patients with S. aureus SSTIs experienced treatment failure. The occurrence of treatment failure was similar among patients with methicillin-resistant S. aureus and those with methicillin-susceptible S. aureus SSTIs (19 vs. 24%; p = 0.70). Independent predictors of treatment failure among cases with S. aureus SSTIs was a duration of infection of ≥7 days prior to initial visit [aOR, 6.02 (95% CI 1.74–19.61)] and a lesion diameter size ≥5 cm [5.25 (1.58–17.20)].

Conclusions

Predictors for treatment failure included a duration of infection for ≥7 days prior to the initial visit and a wound diameter of ≥5 cm. A heightened awareness of these risk factors could help direct targeted interventions in high-risk populations.

Antibiotic stewardship: the lower-extremity physician's prescription for effectively treating infection

The discovery of antibiotic drugs was one of the most significant medical achievements of the 20th century. The improper use of antibiotic drugs to prevent and treat infections has resulted in the emergence of resistance. Antimicrobic stewardship programs are becoming a mainstay in the fight against multidrug-resistant organisms. Individual clinicians should be encouraged to adopt the principles of antibiotic stewardship when treating lower-extremity infections in their scope of practice. First, a review of the available literature outlining the concept and practice of antibiotic stewardship is offered. Second, a discussion describing how to adopt and apply these principles to the individual clinician's practice as it applies to lower-extremity infections is offered. Finally, specific antimicrobial pharmacologic spectra and antibiogram information are offered.

Clinical and Laboratory Features of Community-Associated Methicillin-ResistantStaphylococcus aureus:Is It Really New?

Objective.

To review the epidemiologic and molecular characteristics of community-associated methicillin-resistantStaphylococcus aureus(CA-MRSA) in Detroit, Michigan, to assess the risk factors for infection and the response to therapy.

Design.

Prospective clinical and laboratory study of 2003-2004 CA-MRSA isolates. Molecular features were compared with CA-MRSA isolates from 1980.

Setting.

A 600-bed urban academic medical center.

Patients.

Twenty-three patients with CA-MRSA infections from 2003-2004 were evaluated. In addition, laboratory analysis was performed on 13 CA-MRSA isolates from 1980.

Main Outcome Measures.

Laboratory analysis of isolates included antimicrobial susceptibility testing, pulsed-field genotyping, testing for Panton-Valentine leukocidin (PVL) genes, and staphylococcal cassette chromosomemectyping.

Results.

Patients were predominantly young African American males and presented with skin and soft-tissue infections. All isolates were resistant to erythromycin and highly susceptible to other agents. Patients were generally treated successfully with combination incision and drainage and systemic antibiotics. Among the 23 isolates, 20 (87%) were the same strain. This strain carried the staphylococcal cassette chromosomemectype IV and PVL genes and is genetically identical to USA 300. Thirteen isolates of patients from our community who presented with CA-MRSA infections in 1980 represented a single clone that is unique compared with the 2003-2004 isolates. This strain carried staphylococcal cassette chromosomemectype IVA but did not carry the PVL genes.

Conclusions.

In our community, CA-MRSA is largely due to a single clone with a type IVmecgene and PVL gene. The type IV staphylococcal cassette chromosomemectype can be demonstrated in CA-MRSA isolates from a remote period, suggesting that earlier outbreaks were not related to healthcare exposure.

Antibiotic duration and timing of the switch from intravenous to oral route for bacterial infections in children: systematic review and guidelines

Few studies are available to inform duration of intravenous antibiotics for children and when it is safe and appropriate to switch to oral antibiotics. We have systematically reviewed antibiotic duration and timing of intravenous to oral switch for 36 paediatric infectious diseases and developed evidence-graded recommendations on the basis of the review, guidelines, and expert consensus. We searched databases and obtained information from references identified and relevant guidelines. All eligible studies were assessed for quality. 4090 articles were identified and 170 studies were included. Evidence relating antibiotic duration to outcomes in children for some infections was supported by meta-analyses or randomised controlled trials; in other infections data were from retrospective series only. Criteria for intravenous to oral switch commonly included defervescence and clinical improvement with or without improvement in laboratory markers. Evidence suggests that intravenous to oral switch can occur earlier than previously recommended for some infections. We have synthesised recommendations for antibiotic duration and intravenous to oral switch to support clinical decision making and prospective research.

Prevention of Recurrent Staphylococcal Skin Infections

Staphylococcus aureus infections pose a significant health burden. The emergence of community-associated methicillin-resistant S aureus has resulted in an epidemic of skin and soft tissue infections (SSTI), and many patients experience recurrent SSTI. As S aureus colonization is associated with subsequent infection, decolonization is recommended for patients with recurrent SSTI or in settings of ongoing transmission. S aureus infections often cluster within households, and asymptomatic carriers serve as reservoirs for transmission; therefore, a household approach to decolonization is more effective than measures performed by individuals alone. Novel strategies for the prevention of recurrent SSTI are needed.

Optimizing antimicrobial therapy in children

Management of common infections and optimal use of antimicrobial agents are presented, highlighting new evidence from the medical literature that enlightens practice. Primary therapy of staphylococcal skin abscesses is drainage. Patients who have a large abscess (>5 cm), cellulitis or mixed abscess-cellulitis likely would benefit from additional antibiotic therapy. When choosing an antibiotic for outpatient management, the patient, pathogen and in vitro drug susceptibility as well as tolerability, bioavailability and safety characteristics of antibiotics should be considered. Management of recurrent staphylococcal skin and soft tissue infections is vexing. Focus is best placed on reducing density of the organism on the patient's skin and in the environment, and optimizing a healthy skin barrier. With attention to adherence and optimal dosing, acute uncomplicated osteomyelitis can be managed with early transition from parenteral to oral therapy and with a 3-4 week total course of therapy. Doxycycline should be prescribed when indicated for a child of any age. Its use is not associated with dental staining. Azithromycin should be prescribed for infants when indicated, whilst being alert to an associated ≥2-fold excess risk of pyloric stenosis with use under 6 weeks of age. Beyond the neonatal period, acyclovir is more safely dosed by body surface area (not to exceed 500 mg/m(2)/dose) than by weight. In addition to the concern of antimicrobial resistance, unnecessary use of antibiotics should be avoided because of potential later metabolic effects, thought to be due to perturbation of the host's microbiome.

Empirical therapy in Methicillin-resistant Staphylococcus Aureus infections: An Up-To-Date approach

Methicillin-resistant Staphylococcus aureus (MRSA) continues to be an important pathogen worldwide, with high prevalence of infection in both community and hospital settings. Timely and appropriate choice of empirical therapy in the setting of MRSA infection is imperative due to the high rate of associated morbidity and mortality with MRSA infections. Initial choices should be made based on the site and severity of the infection, most notably moderate skin and soft tissue infections which may be treated with oral antibiotics (trimethoprim-sulfamethoxazole, clindamycin, doxycycline/minocycline, linezolid) in the outpatient setting, versus choice of parenteral therapy in the inpatient setting of more invasive or severe disease. Though the current recommendations continue to strongly rely on vancomycin as a standard empiric choice in the setting of severe/invasive infections, alternative therapies exist with studies supporting their non-inferiority. This includes the use of linezolid in pneumonia and severe skin and skin structure infections (SSSI) and daptomycin for MRSA bacteremia, endocarditis, SSSIs and bone/joint infections. Additionally, concerns continue to arise in regards to vancomycin, such as increasing isolate MICs, and relatively high rates of clinical failures with vancomycin. Thus, the growing interest in vanomycin alternatives, such as ceftaroline, ceftobribole, dalbavancin, oritavancin, and tedizolid, and their potential role in treating MRSA infections.

Trimethoprim-Sulfamethoxazole versus Placebo for Uncomplicated Skin Abscess

BACKGROUND

U.S. emergency department visits for cutaneous abscess have increased with the emergence of methicillin-resistant Staphylococcus aureus (MRSA). The role of antibiotics for patients with a drained abscess is unclear.

METHODS

We conducted a randomized trial at five U.S. emergency departments to determine whether trimethoprim-sulfamethoxazole (at doses of 320 mg and 1600 mg, respectively, twice daily, for 7 days) would be superior to placebo in outpatients older than 12 years of age who had an uncomplicated abscess that was being treated with drainage. The primary outcome was clinical cure of the abscess, assessed 7 to 14 days after the end of the treatment period.

RESULTS

The median age of the participants was 35 years (range, 14 to 73); 45.3% of the participants had wound cultures that were positive for MRSA. In the modified intention-to-treat population, clinical cure of the abscess occurred in 507 of 630 participants (80.5%) in the trimethoprim-sulfamethoxazole group versus 454 of 617 participants (73.6%) in the placebo group (difference, 6.9 percentage points; 95% confidence interval [CI], 2.1 to 11.7; P=0.005). In the per-protocol population, clinical cure occurred in 487 of 524 participants (92.9%) in the trimethoprim-sulfamethoxazole group versus 457 of 533 participants (85.7%) in the placebo group (difference, 7.2 percentage points; 95% CI, 3.2 to 11.2; P<0.001). Trimethoprim-sulfamethoxazole was superior to placebo with respect to most secondary outcomes in the per-protocol population, resulting in lower rates of subsequent surgical drainage procedures (3.4% vs. 8.6%; difference, -5.2 percentage points; 95% CI, -8.2 to -2.2), skin infections at new sites (3.1% vs. 10.3%; difference, -7.2 percentage points; 95% CI, -10.4 to -4.1), and infections in household members (1.7% vs. 4.1%; difference, -2.4 percentage points; 95% CI, -4.6 to -0.2) 7 to 14 days after the treatment period. Trimethoprim-sulfamethoxazole was associated with slightly more gastrointestinal side effects (mostly mild) than placebo. At 7 to 14 days after the treatment period, invasive infections had developed in 2 of 524 participants (0.4%) in the trimethoprim-sulfamethoxazole group and in 2 of 533 participants (0.4%) in the placebo group; at 42 to 56 days after the treatment period, an invasive infection had developed in 1 participant (0.2%) in the trimethoprim-sulfamethoxazole group.

CONCLUSIONS

In settings in which MRSA was prevalent, trimethoprim-sulfamethoxazole treatment resulted in a higher cure rate among patients with a drained cutaneous abscess than placebo. (Funded by the National Institute of Allergy and Infectious Diseases; ClinicalTrials.gov number, NCT00729937.).

Point-of-Care Ultrasonography for the Diagnosis of Pediatric Soft Tissue Infection

OBJECTIVES

To determine the test characteristics of point-of-care ultrasonography for the identification of a drainable abscess and to compare the test characteristics of ultrasonography with physical examination. In addition, we sought to measure the extent to which ultrasonography impacts clinical management of children with skin and soft tissue infections (SSTIs).

STUDY DESIGN

We performed a prospective study of children with SSTIs evaluated in a pediatric emergency department. Treating physicians recorded their initial impression of whether a drainable abscess was present based on physical examination. Another physician, blinded to the treating physician's assessment, performed an ultrasound study and conveyed their interpretation and recommendations to the treating physician. Any management change was recorded. An abscess was defined as a lesion from which purulent fluid was expressed during a drainage procedure in the emergency department or during the 2- to 5-day follow-up period. We defined a change in management as correct when the ultrasound diagnosis was discordant from physical examination and matched the ultimate lesion classification.

RESULTS

Of 151 SSTIs evaluated among 148 patients, the sensitivity and specificity of point-of-care ultrasonography for the presence of abscess were 96% (95% CI 90%-99%) and 87% (74%-95%), respectively. The sensitivity and specificity of physical examination for the presence of abscess were 84% (75%-90%) and 60% (44%-73%), respectively. For every 4 ultrasound examinations performed, there was 1 correct change in management.

CONCLUSIONS

Point-of-care ultrasonography demonstrates excellent test characteristics for the identification of skin abscess and has superior test characteristics compared with physical examination alone.

Trimethoprim-Sulfamethoxazole Therapy Reduces Failure and Recurrence in Methicillin-Resistant Staphylococcus aureus Skin Abscesses after Surgical Drainage

OBJECTIVE

To determine whether a 3-day vs 10-day course of antibiotics after surgical drainage of skin abscesses is associated with different failure and recurrence rates.

STUDY DESIGN

Patients age 3 months to 17 years seeking care at a pediatric emergency department with an uncomplicated skin abscess that required surgical drainage were randomized to receive 3 or 10 days of oral trimethoprim-sulfamethoxazole therapy. Patients were evaluated 10-14 days later to assess clinical outcome. Patients were followed for 6 months to determine the cumulative rate of recurrent skin infections.

RESULTS

Among the 249 patients who were enrolled, 87% of wound cultures grew Staphylococcus aureus (S aureus) (55% methicillin-resistant S aureus [MRSA], 32% methicillin-sensitive S aureus), 11% other organisms, and 2% no growth. Thirteen patients experienced treatment failure. Among all patients, no significant difference in failure rates between the 3- and 10-day treatment groups was found. After we stratified patients by the infecting organism, only patients with MRSA infection were more likely to experience treatment failure in the 3-day group than the 10-day group (P = .03, rate difference 10.1%, 95% CI 2.1%-18.2%) Recurrent infection within 1 month of surgical drainage was more likely in patients infected with MRSA who received 3 days of antibiotics. (P = .046, rate difference 10.3%, 95% CI 0.8%-19.9%).

CONCLUSION

Patients with MRSA skin abscesses are more likely to experience treatment failure and recurrent skin infection if given 3 rather than 10 days of trimethoprim-sulfamethoxazole after surgical drainage.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT02024867.

Staphylococcus aureus Isolates Carrying Panton-Valentine Leucocidin Genes: Their Frequency, Antimicrobial Patterns, and Association With Infectious Disease in Shahrekord City, Southwest Iran

Background:

A diversity of virulence factors work together to create the pathogenicity of Staphylococcus aureus. These factors include cell surface components that promote adherence to surfaces as well as exoproteins such as Panton-Valentine leukocidin (PVL), encoded by the luk-PV genes, that invade or bypass the immune system and are toxic to the host, thereby enhancing the severity of infections caused by methicillin-resistant Staphylococcus aureus (MRSA).

Objectives:

The aim of this study was to determine the frequency of PVL-positive MRSA strains by real-time PCR and their antibiotic susceptibility patterns by phenotypic test.

Materials and Methods:

In total, 284 Staphylococcus isolates, identified by phenotypic methods from clinical samples of Shahrekord University Hospitals, Shahrekord, Iran, were tested for nuc, mecA, and PVL genes by TaqMan real-time PCR. The antibiotic susceptibility patterns of PVL-containing MRSA strains were determined via the disk diffusion method.

Results:

In total, 196 isolates (69%) were nuc positive (i.e., S. aureus); of those isolates, 96 (49%) were mecA positive (MRSA). Eighteen (18.8%) of the 96 MRSA positive and 3 (3%) of the 100 methicillin-susceptible Staphylococcus aureus (MSSA) strains were PVL positive. PVL-positive MRSA strains were mostly recovered from tracheal specimens. Eight PVL-positive MRSA strains were resistant to all the tested antibiotics except vancomycin. A significant correlation (P = 0.001) was found between the mecA positivity and the presence of luk-PV genes.

Conclusions:

Community acquired (CA)-MRSA is becoming a public health concern in many parts of the world, including Asian countries. The variable prevalence of luk-PV-positive MRSA isolates in different regions and their rather high frequency in pneumonia necessitate the application of rapid diagnostic methods such as real-time PCR to improve treatment effectiveness.

Typing of Methicillin Resistant Staphylococcus Aureus Using DNA Fingerprints by Pulsed-field Gel Electrophoresis

Background:

Methicillin resistant Staphylococcus aureus (MRSA) is responsible for a wide spectrum of nosocomial and community associated infections worldwide. The aim of this study was to analyze MRSA strains from the general population in Canton Sarajevo, B&H.

Methods:

Our investigation including either phenotypic and genotypic markers such as antimicrobial resistance, pulsed-field gel electrophoresis (PFGE), SCC typing, and Panton-Valentine leukocidin (PVL) detection.

Results:

Antimicrobial susceptibility: all MRSA isolates were resistant to the β-lactam antibiotics tested, and all isolates were susceptible trimethoprim sulphamethoxazole, rifampicin, fusidic acid, linezolid and vancomycin. Sixty-eight per cent of the MRSA isolates were resistant to erythromycin, 5% to clindamycin, 5% to gentamicin and 4% to ciprofloxacin. After the PFGE analysis, the isolates were grouped into five similarity groups: A-E. The largest number of isolates belonged to one of two groups: C: 60 (60%) and D: 27 (27%). In both groups C and D, SCCmec type IV was predominant (60% and 88, 8%, respectively). A total of 24% of the isolates had positive expression of PVL genes, while 76% showed a statistically significantly greater negative expression of PVL genes.

Conclusion:

SCCmec type IV, together with the susceptibility profile and PFGE grouping, is considered to be typical of CA-MRSA

Clinical management of skin and soft tissue infections in the U.S. Emergency Departments

Introduction

Community-associated methicillin resistant Staphylococcus aureus (CA-MRSA) has emerged as the most common cause of skin and soft-tissue infections (SSTI) in the United States. A nearly three-fold increase in SSTI visit rates had been documented in the nation’s emergency departments (ED). The objective of this study was to determine characteristics associated with ED performance of incision and drainage (I+D) and use of adjuvant antibiotics in the management of skin and soft tissue infections (SSTI).

Methods

Cross-sectional study of the National Hospital Ambulatory Medical Care Survey, a nationally representative database of ED visits from 2007–09. Demographics, rates of I+D, and adjuvant antibiotic therapy were described. We used multivariable regression to identify factors independently associated with use of I+D and adjuvant antibiotics.

Results

An estimated 6.8 million (95% CI: 5.9–7.8) ED visits for SSTI were derived from 1,806 sampled visits; 17% were for children <18 years of age and most visits were in the South (49%). I+D was performed in 27% (95% CI 24–31) of visits, and was less common in subjects <18 years compared to adults 19–49 years (p<0.001), and more common in the South. Antibiotics were prescribed for 85% of SSTI; there was no relationship to performance of I+D (p=0.72). MRSA-active agents were more frequently prescribed after I+D compared to non-drained lesions (70% versus 56%, p<0.001). After multivariable adjustment, I+D was associated with presentation in the South (OR 2.36; 95% CI 1.52–3.65 compared with Northeast), followed by West (OR 2.13; 1.31–3.45), and Midwest (OR 1.96; 1.96–3.22).

Conclusion

Clinical management of most SSTIs in the U.S. involves adjuvant antibiotics, regardless of I+D. Although not necessarily indicated, CA-MRSA effective therapy is being used for drained SSTI.

Cutaneous infectious diseases: Kids are not just little people

The changes in immune response that occur with age play a significant role in disease presentation and patient management. Evolution of the innate and adaptive immune systems throughout life, influenced partly by hormonal changes associated with puberty, plays a role in the differences between pediatric and adult response to disease. We review a series of manifestations of dermatologic infectious diseases spanning bacterial, viral, and fungal origins that can be seen in both pediatric and adult age groups and highlight similarities and differences in presentation and disease course. Therapeutic options are also discussed for these infectious diseases, with particular attention to variations in management between these population subgroups, given differences in pharmacokinetics and side effect profiles.

Telavancin for Acute Bacterial Skin and Skin Structure Infections, a Post Hoc Analysis of the Phase 3 ATLAS Trials in Light of the 2013 FDA Guidance

Two phase 3 ATLAS trials demonstrated noninferiority of telavancin compared with vancomycin for complicated skin and skin structure infections. Data from these trials were retrospectively evaluated according to 2013 U.S. Food and Drug Administration (FDA) guidance on acute bacterial skin and skin structure infections. This post hoc analysis included patients with lesion sizes of ≥75 cm(2) and excluded patients with ulcers or burns (updated all-treated population; n = 1,127). Updated day 3 (early) clinical response was defined as a ≥20% reduction in lesion size from baseline and no rescue antibiotic. Updated test-of-cure (TOC) clinical response was defined as a ≥90% reduction in lesion size, no increase in lesion size since day 3, and no requirement for additional antibiotics or significant surgical procedures. Day 3 (early) clinical responses were achieved in 62.6% and 61.0% of patients receiving telavancin and vancomycin, respectively (difference, 1.7%, with a 95% confidence interval [CI] of -4.0% to 7.4%). Updated TOC visit cure rates were similar for telavancin (68.0%) and vancomycin (63.3%), with a difference of 4.8% (95% CI, -0.7% to 10.3%). Adopting current FDA guidance, this analysis corroborates previous noninferiority findings of the ATLAS trials of telavancin compared with vancomycin.

Staphylococcus aureus infections: epidemiology, pathophysiology, clinical manifestations, and management

Staphylococcus aureus is a major human pathogen that causes a wide range of clinical infections. It is a leading cause of bacteremia and infective endocarditis as well as osteoarticular, skin and soft tissue, pleuropulmonary, and device-related infections. This review comprehensively covers the epidemiology, pathophysiology, clinical manifestations, and management of each of these clinical entities. The past 2 decades have witnessed two clear shifts in the epidemiology of S. aureus infections: first, a growing number of health care-associated infections, particularly seen in infective endocarditis and prosthetic device infections, and second, an epidemic of community-associated skin and soft tissue infections driven by strains with certain virulence factors and resistance to β-lactam antibiotics. In reviewing the literature to support management strategies for these clinical manifestations, we also highlight the paucity of high-quality evidence for many key clinical questions.

Risk Factors Associated With Abscess Formation in Children 5 Years of Age and Younger

From 1997 to 2009, hospitalization rates have doubled for pediatric patients with soft tissue abscesses requiring incision and drainage. Despite this increasing national burden, few studies have been conducted to identify the risk factors associated with abscess formation. Our study evaluates a collection of physiological and lifestyle parameters that may serve as risk factors for abscess formation among pediatric patients 5 years of age or younger. Our results indicate family history and age 2 years and younger are associated with higher risk of abscess formation. Furthermore, methicillin-resistant Staphylococcus aureus and methicillin-susceptible Staphylococcus aureus were prevalent pathogens associated with abscess in our study group. Pediatricians may employ these novel parameters to educate parents and/or guardians of high-risk groups on preventing abscess formation to alleviate the burden of incision & dragining requiring abscess on health care costs.

Community-associated methicillin-resistant Staphylococcus aureus: prevalence in skin and soft tissue infections at emergency departments in the Greater Toronto Area and associated risk factors

Objective:

Community-associated methicillin-resistantStaphylococcus aureus(CA-MRSA), which is caused primarily by the Canadian methicillin-resistantStaphylococcus aureus-10 (CMRSA-10) strain (also known as the USA300 strain) has emerged rapidly in the United States and is now emerging in Canada. We assessed the prevalence, risk factors, microbiological characteristics and outcomes of CA-MRSA in patients with purulent skin and soft tissue infections (SSTIs) presenting to emergency departments (EDs) in the Greater Toronto Area.

Methods:

Patients withStaphylococcus aureusSSTIs who presented to 7 EDs between Mar. 1 and Jun. 30, 2007, were eligible for inclusion in this study. Antimicrobial susceptibilities and molecular characteristics of MRSA strains were identified. Demographic, risk factor and clinical data were collected through telephone interviews.

Results:

MRSA was isolated from 58 (19%) of 299 eligible patients. CMRSA-10 was identified at 6 of the 7 study sites and accounted for 29 (50%) of all cases of MRSA. Telephone interviews were completed for 161 of the eligible patients. Individuals with CMRSA-10 were younger (median 34 v. 63 yr,p= 0.002), less likely to report recent antibiotic use (22% v. 67%,p= 0.046) or health care–related risk factors (33% v. 72%,p= 0.097) and more likely to report community-related risk factors (56% v. 6%,p= 0.008) than patients with other MRSA strains. CMRSA-10 SSTIs were treated with incision and drainage (1 patient), antibiotic therapy (3 patients) or both (5 patients), and all resolved. CMRSA-10 isolates were susceptible to clindamycin, tetracycline and trimethoprimsulfamethoxazole.

Conclusion:

CA-MRSA is a significant cause of SSTIs in the Greater Toronto Area, and can affect patients without known community-related risk factors. The changing epidemiology of CA-MRSA necessitates further surveillance to inform prevention strategies and empiric treatment guidelines.

Failure of Emergency Department Observation Unit Treatment for Skin and Soft Tissue Infections

BACKGROUND

The effectiveness of observation unit (OU) management of skin and soft tissue infections (SSTI) has not been fully evaluated.

OBJECTIVE

This study was performed to determine the rate and risk factors.

METHODS

Retrospective cohort study of children ages 2 months to 18 years admitted to the OU for an SSTI between 2007 and 2010 from a pediatric emergency department (ED). Failure of OU therapy was defined as subsequent inpatient ward admission, re-admission after discharge from OU, initial or repeat incision and drainage after OU admission, or change in antibiotic therapy. Demographic, clinical, and lesion characteristics were collected. Comparative analyses were conducted to determine factors associated with OU failure; prolonged OU admission, defined as length of stay ≥ 36 h was evaluated.

RESULTS

One hundred ninety-two (63.2%) of 304 subjects with SSTI were eligible; mean age was 6.2 ± 5.3 years, and 52% were male. Fever (≥38°C) in the ED was present for 77 (40%). Most lesions were skin abscesses (53%) and were located on the lower extremity (36%) and buttock/genitourinary (21%). OU treatment failure occurred in 22% (95% confidence interval [CI] 16.5-28.3), primarily due to inpatient admission. Fever on ED presentation was significantly associated with OU failure (odds ratio 2.02; 95% CI 1.02-4.02). Demographics, body site, presence of abscess, and methicillin-resistant Staphylococcus aureus were not associated with OU failure. Prolonged OU admission occurred in 18 subjects (9.4%).

CONCLUSION

SSTI can be successfully treated in the OU, though febrile children with SSTI are at risk for OU treatment failure and should be considered for inpatient admission.

Clindamycin versus trimethoprim-sulfamethoxazole for uncomplicated skin infections

BACKGROUND

Skin and skin-structure infections are common in ambulatory settings. However, the efficacy of various antibiotic regimens in the era of community-acquired methicillin-resistant Staphylococcus aureus (MRSA) is unclear.

METHODS

We enrolled outpatients with uncomplicated skin infections who had cellulitis, abscesses larger than 5 cm in diameter (smaller for younger children), or both. Patients were enrolled at four study sites. All abscesses underwent incision and drainage. Patients were randomly assigned in a 1:1 ratio to receive either clindamycin or trimethoprim-sulfamethoxazole (TMP-SMX) for 10 days. Patients and investigators were unaware of the treatment assignments and microbiologic test results. The primary outcome was clinical cure 7 to 10 days after the end of treatment.

RESULTS

A total of 524 patients were enrolled (264 in the clindamycin group and 260 in the TMP-SMX group), including 155 children (29.6%). One hundred sixty patients (30.5%) had an abscess, 280 (53.4%) had cellulitis, and 82 (15.6%) had mixed infection, defined as at least one abscess lesion and one cellulitis lesion. S. aureus was isolated from the lesions of 217 patients (41.4%); the isolates in 167 (77.0%) of these patients were MRSA. The proportion of patients cured was similar in the two treatment groups in the intention-to-treat population (80.3% in the clindamycin group and 77.7% in the TMP-SMX group; difference, -2.6 percentage points; 95% confidence interval [CI], -10.2 to 4.9; P=0.52) and in the populations of patients who could be evaluated (466 patients; 89.5% in the clindamycin group and 88.2% in the TMP-SMX group; difference, -1.2 percentage points; 95% CI, -7.6 to 5.1; P=0.77). Cure rates did not differ significantly between the two treatments in the subgroups of children, adults, and patients with abscess versus cellulitis. The proportion of patients with adverse events was similar in the two groups.

CONCLUSIONS

We found no significant difference between clindamycin and TMP-SMX, with respect to either efficacy or side-effect profile, for the treatment of uncomplicated skin infections, including both cellulitis and abscesses. (Funded by the National Institute of Allergy and Infectious Diseases and the National Center for Advancing Translational Sciences, National Institutes of Health; ClinicalTrials.gov number, NCT00730028.).

Prevalence of methicillin-resistant Staphylococcus aureus in skin and soft tissue infections in patients presenting to Canadian emergency departments

Background:

Community-associated methicillin-resistantStaphylococcus aureus(MRSA) is an increasingly common cause of skin and soft tissue infection (SSTI) worldwide. The prevalence of MRSA in SSTIs across Canada has not been well described. Studies in the United States have shown significant geographic variability in the prevalence of MRSA. This study characterizes the geographic prevalence and microbiology of MRSA in patients presenting to Canadian emergency departments with SSTIs.

Methods:

Using a prospective, observational design, we enrolled patients with acute purulent SSTIs presenting to 17 hospital emergency departments and 2 community health centres (spanning 6 Canadian provinces) between July 1, 2008, and April 30, 2009. Eligible patients were those whose wound cultures grewS. aureus. MRSA isolates were characterized by antimicrobial susceptibility testing and pulsed-field gel electrophoresis. All patients were subjected to a structured chart audit, and patients whose wound swabs grew MRSA were contacted by telephone to gather detailed information regarding risk factors for MRSA infection, history of illness, and outcomes.

Results:

Of the 1,353S. aureus–positive encounters recorded, 431 (32%) grew MRSA and 922 (68%) wounds grew methicillin-susceptibleS. aureus. We observed significant variation in both the prevalence of MRSA (11–100%) and the proportion of community-associated strains of MRSA (0– 100%) across our study sites, with a significantly higher prevalence of MRSA in western Canada.

Interpretation:

MRSA continues to emerge across Canada, and the prevalence of MRSA in SSTIs across Canada is variable and higher than previously expected.

Methicillin-resistant Staphylococcus Aureus Lip Infection Mimicking Angioedema

BACKGROUND

It is rare for angioedema to be misidentified by the experienced clinician or for it to mimic another disease process. As an Emergency Physician, it is important to recognize and treat angioedema immediately. Of equal importance is the recognition and initiation of treatment of facial cellulitis. A case report follows that illustrates methicillin-resistant Staphylococcus aureus (MRSA) lip infection mimicking angioedema.

CASE REPORT

Here, we describe a case of a 21-year-old man who presented with a swollen lower lip, initially diagnosed as angioedema. Further investigation revealed the cause of his lip swelling was actually a MRSA abscess and surrounding cellulitis, an unusual presentation for lip infection, which we discuss below. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Misidentifying MRSA lip infection for angioedema, with a delay in proper treatment, could result in serious morbidity or mortality.

A case of community-associated methicillin-resistant Staphylococcus aureus infections in a community hospital

Infections caused by methicillin-resistant Staphylococcus Aureus (MRSA) have recently occurred in communities in people lacking known healthcare risk factors. This MRSA infection is referred to as community-associated MRSA (CA-MRSA) infection, and is distinct from hospital-associated MRSA infection, which occurs in people with risk factors. We experienced a patient diagnosed with CA-MRSA cellulitis, as culture of pus revealed MRSA and he had not been exposed to healthcare environments for the past year. The patient was a previously healthy 38-year-old man with suppurative cellulitis in his right index finger following injury to the finger at his worksite. The cellulitis was successfully managed with incision and drainage (I&D), followed by cefazolin during a 10-day clinical course, although the patient’s MRSA strain was resistant to cefazolin. There are several reports that suggest that I&D followed by antibiotic treatment for CA-MRSA skin infection produces equivalent clinical outcomes, whether the antibiotic prescribed was effective or not. Given that MRSA emerged in an outpatient setting, CA-MRSA should be considered a possible etiology of skin infection in healthy individuals with no classical risk factors for acquisition of MRSA.

Methicillin-resistant staphylococcus aureus bone and joint infections in children

Methicillin-resistant Staphylococcus aureus has been a clinically significant pathogen in orthopaedics for more than a decade. Research shows that these infections are more virulent and that treatment requires greater use of hospital resources. A multidisciplinary approach involving emergency department physicians, radiologists, interventional radiologists, MRI technicians, pediatricians, infectious disease specialists, anesthesiologists, and orthopaedic surgeons is necessary to optimize outcomes and minimize costs. Early use of MRI helps delineate the extent of infection, aids in the consideration of surgery, and provides valuable information for surgical planning. Healthcare providers need to stay vigilant during the course of the disease to detect other sites of infection or complications of methicillin-resistant S aureus, such as deep vein thrombosis and septic pulmonary emboli. Patients with infections near growth centers require long-term monitoring to ensure the absence of growth disturbances. Physicians should help educate patients and families on prevention strategies and be aware of guidelines for students to return to school and athletes to return to play.

Genotyping of Methicillin Resistant Staphylococcus aureus Strains Isolated from Hospitalized Children

Community associated methicillin resistant Staphylococcus aureus (CA-MRSA) is an emerging pathogen increasingly reported to cause skin and soft tissue infections for children. The emergence of highly virulencet CA-MRSA strains in the immunodeficiency of young children seemed to be the basic explanation of the increased incidence of CA-MRSA infections among this population. The subjects of this study were 8 patients hospitalized in the Pediatric Department at the University Hospital of Monastir. The patients were young children (aged from 12 days to 18 months) who were suffering from MRSA skin infections; two of them had the infections within 72 h of their admission. The isolates were classified as community isolates as they all carried the staphylococcal cassette chromosome mec (SCCmec) IV and pvl genes. Epidemiological techniques, pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST), were applied to investigate CA-MRSA strains. Analysis of molecular data revealed that MRSA strains were related according to PFGE patterns and they belonged to a single clone ST80. Antimicrobial susceptibility tests showed that all strains were resistant to kanamycin and 2 strains were resistant to erythromycin.

Clinical characteristics and antibiotic utilization in pediatric patients hospitalized with acute bacterial skin and skin structure infection

BACKGROUND

Hospitalizations for acute bacterial skin and skin structure infection (ABSSSI) in children are increasingly frequent, but little is known about antibiotic utilization. In adults, recent studies suggest substantial opportunity to reduce broad-spectrum antibiotic use and shorten therapy. We sought to determine whether similar opportunity exists in children.

METHODS

This was a planned secondary analysis of a pediatric cohort taken from a multicenter, retrospective cohort of patients hospitalized for ABSSSI between June 1, 2010, and May 31, 2012. The prespecified primary endpoint was a composite of 2 prescribing practices: (1) use of antibiotics with broad Gram-negative activity or (2) treatment duration >10 days.

RESULTS

One-hundred and two patients ≤ 18 years old were included: 43 had non-purulent cellulitis, 19 had wound infection or purulent cellulitis and 40 had cutaneous abscess. The median age was 5 years (range 45 days to 18 years). Clindamycin was the most frequently prescribed antibiotic during hospitalization (67% of cases) and at discharge (66% of cases). The median duration of therapy was 11 days (interquartile range 10-12) and was similar for all 3 types of ABSSSI. The primary endpoint occurred in 67% of cases, including broad Gram-negative therapy in 25% and treatment duration >10 days in 61%. By multivariate logistic regression, admission through an emergency department and management by a medical (vs. surgical) service were independently associated with the primary endpoint.

CONCLUSIONS

Children hospitalized for ABSSSI are frequently exposed to antibiotics with broad Gram-negative activity or treated longer than 10 days suggesting opportunity to reduce antibiotic use.

Cutaneous bacterial infections caused by Staphylococcus aureus and Streptococcus pyogenes in infants and children

Acute bacterial skin and skin structure infections (SSSIs) are among the most common bacterial infections in children. The medical burden of SSSIs, particularly abscesses, has increased nationwide since the emergence of community-acquired methicillin-resistant Staphylococcus aureus. SSSIs represent a wide spectrum of disease severity. Prompt recognition, timely institution of appropriate therapy, and judicious antimicrobial use optimize patient outcomes. For abscesses, incision and drainage are paramount and might avoid the need for antibiotic treatment in uncomplicated cases. If indicated, empiric antimicrobial therapy should target Streptococcus pyogenes for nonpurulent SSSIs, such as uncomplicated cellulitis, and S aureus for purulent SSSIs such as abscesses.

Epidemiology and treatment of community-associated methicillin-resistantStaphylococcus aureusin children

Similar to the epidemiology of methicillin-sensitive Staphylococcus aureus, community-associated methicillin-resistant S. aureus infections occur in children in different regions of the USA and throughout the world. Although minor skin and soft-tissue infections predominate, life-threatening invasive disease and death can result. The novel genetic elements, staphylococcal cassette chromosome mec IV and V, explain the narrow antibiotic resistance pattern, and suggest the mechanism of spread among staphylococci. Panton-Valentine leukocidin apparently plays a role in its pathogenesis. Clindamycin therapy is often effective for treatment, but inducible resistance can develop if the isolate exhibits macrolide resistance due to the erm mechanism. Other drugs displaying in vitro activity against community-associated methicillin-resistant S. aureus include trimethoprim-sulfamethoxazole, tetracyclines, quinolones, linezolid and vancomycin. While experience in pediatric patients is limited, daptomycin, ketolides, glycylcyclines, newer glycopeptides and beta-lactamase-stable cephalosporins may be useful in the future. Further research could include well-designed studies of mechanisms of virulence, continued surveillance of changes in pathogenicity and susceptibility, as well as treatment effectiveness.