Emergence of community-acquired methicillin-resistant Staphylococcus aureus skin and soft tissue infections as a common cause of hospitalization in United States children

Pre- and Post-admission Care for Children Hospitalized With Skin and Soft Tissue Infections

BACKGROUND AND OBJECTIVES

Although skin and soft tissue infections (SSTIs) are among the most common indications for pediatric hospitalization, little is known about outpatient care received for SSTI before and after hospitalization. We assessed peri-hospitalization care for SSTI, including antibiotic exposures and their impact on hospital length of stay (LOS).

METHODS

This is a retrospective cohort study of 1229 SSTI hospitalizations in 2019 from children aged 1-to-18 years enrolled in Medicaid from 10 US states included in the Merative Marketscan Medicaid database. We characterized health service utilization (outpatient visits, laboratory and diagnostic tests, antibiotic exposures) 14 days before and 30 days after hospitalization and evaluated the effects of pre-hospitalization care on hospital LOS with linear regression.

RESULTS

Only 43.1% of children hospitalized with SSTI had a preceding outpatient visit with a SSTI diagnosis, 69.8% of which also filled prescription for an antibiotic. Median LOS for SSTI admission was 2 days (interquartile range 1-3). Pre-hospitalization visits with a diagnosis of SSTI were associated with a 0.7 day reduction (95% confidence interval: 0.6-0.81) in LOS (P < .001), but pre-hospital antibiotic exposure alone had no effect on LOS. Most children (81.7%) filled antibiotic prescriptions after hospital discharge and 74.5% had post-discharge ambulatory visits.

CONCLUSIONS

Although most children did not receive pre-admission care for SSTI, those that did had a shorter hospitalization. Further investigation is necessary on how to optimize access and use of outpatient care for SSTI.

Race, ethnicity, and risk for colonization and infection with key bacterial pathogens: a scoping review

Background

Racial and ethnic disparities in infectious disease burden have been reported in the USA and globally, most recently for COVID-19. It remains unclear whether such disparities also exist for priority bacterial pathogens that are increasingly antimicrobial-resistant. We conducted a scoping review to summarize published studies that report on colonization or community-acquired infection with pathogens among different races and ethnicities.

Methods

We conducted an electronic literature search of MEDLINE®, Daily, Global Health, Embase, Cochrane Central, and Web of Science from inception to January 2022 for eligible observational studies. Abstracts and full-text publications were screened in duplicate for studies that reported data for race or ethnicity for at least one of the pathogens of interest.

Results

Fifty-four observational studies in 59 publications met our inclusion criteria. Studies reported results for Staphylococcus aureus (n=56), Escherichia coli (n=8), Pseudomonas aeruginosa (n=2), Enterobacterales (n=1), Enterococcus faecium (n=1), and Klebsiella pneumoniae (n=1), and were conducted in the USA (n=42), Israel (n=5), New Zealand (n=4), Australia (n=2), and Brazil (n=1). USA studies most often examined Black and Hispanic minority groups and regularly reported a higher risk of these pathogens in Black persons and mixed results for Hispanic persons. Ethnic minority groups were often reported to be at a higher risk in other countries.

Conclusion

Sufficient evidence was identified to justify systematic reviews and meta-analyses evaluating the relationship between race, ethnicity, and community-acquired S. aureus and E. coli, although data were rare for other pathogens. We recommend that future studies clarify whether race and ethnicity data are self-reported, collect race and ethnicity data in conjunction with the social determinants of health, and make a concerted effort to include non-English speakers and Indigenous populations from the Americas, when possible.

Socioeconomic status and the risk for colonization or infection with priority bacterial pathogens: a global evidence map

Low socioeconomic status (SES) is thought to exacerbate risks for bacterial infections, but global evidence for this relationship has not been synthesized. We systematically reviewed the literature for studies describing participants' SES and their risk of colonization or community-acquired infection with priority bacterial pathogens. Fifty studies from 14 countries reported outcomes by participants' education, healthcare access, income, residential crowding, SES deprivation score, urbanicity, or sanitation access. Low educational attainment, lower than average income levels, lack of healthcare access, residential crowding, and high deprivation were generally associated with higher risks of colonization or infection. There is limited research on these outcomes in low- and middle-income countries (LMICs) and conflicting findings regarding the effects of urbanicity. Only a fraction of studies investigating pathogen colonization and infection reported data stratified by participants' SES. Future studies should report stratified data to improve understanding of the complex interplay between SES and health, especially in LMICs.

Staphylococcus aureus Infections and Human Intestinal Microbiota

Staphylococcus aureus (S. aureus) is a common pathogen that can cause many human diseases, such as skin infection, food poisoning, endocarditis, and sepsis. These diseases can be minor infections or life-threatening, requiring complex medical management resulting in substantial healthcare costs. Meanwhile, as the critically ignored "organ," the intestinal microbiome greatly impacts physiological health, not only in gastrointestinal diseases but also in disorders beyond the gut. However, the correlation between S. aureus infection and intestinal microbial homeostasis is largely unknown. Here, we summarized the recent progress in understanding S. aureus infections and their interactions with the microbiome in the intestine. These summarizations will help us understand the mechanisms behind these infections and crosstalk and the challenges we are facing now, which could contribute to preventing S. aureus infections, effective treatment investigation, and vaccine development.

Climate Change, Skin Health, and Dermatologic Disease: A Guide for the Dermatologist

Climate change has a pervasive impact on health and is of clinical relevance to every organ system. Climate change-related factors impact the skin's capacity to maintain homeostasis, leading to a variety of cutaneous diseases. Stratospheric ozone depletion has led to increased risk of melanoma and keratinocyte carcinomas due to ultraviolet radiation exposure. Atopic dermatitis, psoriasis, pemphigus, acne vulgaris, melasma, and photoaging are all associated with rising levels of air pollution. Elevated temperatures due to global warming induce disruption of the skin microbiome, thereby impacting atopic dermatitis, acne vulgaris, and psoriasis, and high temperatures are associated with exacerbation of skin disease and increased risk of heat stroke. Extreme weather events due to climate change, including floods and wildfires, are of relevance to the dermatologist as these events are implicated in cutaneous injuries, skin infections, and acute worsening of inflammatory skin disorders. The health consequences as well as the economic and social burden of climate change fall most heavily on vulnerable and marginalized populations due to structural disparities. As dermatologists, understanding the interaction of climate change and skin health is essential to appropriately manage dermatologic disease and advocate for our patients.

Clinical Impact of Staphylococcus aureus Skin and Soft Tissue Infections

The pathogenic bacterium Staphylococcus aureus is the most common pathogen isolated in skin-and-soft-tissue infections (SSTIs) in the United States. Most S. aureus SSTIs are caused by the epidemic clone USA300 in the USA. These infections can be serious; in 2019, SSTIs with S. aureus were associated with an all-cause, age-standardized mortality rate of 0.5 globally. Clinical presentations of S. aureus SSTIs vary from superficial infections with local symptoms to monomicrobial necrotizing fasciitis, which can cause systemic manifestations and may lead to serious complications or death. In order to cause skin infections, S. aureus employs a host of virulence factors including cytolytic proteins, superantigenic factors, cell wall-anchored proteins, and molecules used for immune evasion. The immune response to S. aureus SSTIs involves initial responders such as keratinocytes and neutrophils, which are supported by dendritic cells and T-lymphocytes later during infection. Treatment for S. aureus SSTIs is usually oral therapy, with parenteral therapy reserved for severe presentations; it ranges from cephalosporins and penicillin agents such as oxacillin, which is generally used for methicillin-sensitive S. aureus (MSSA), to vancomycin for methicillin-resistant S. aureus (MRSA). Treatment challenges include adverse effects, risk for Clostridioides difficile infection, and potential for antibiotic resistance.

Escalation of antimicrobial resistance among MRSA part 2: focus on infections and treatment

INTRODUCTION

MRSA is associated with causing a variety of infections including skin and skin structure infections, catheter and device-related (e.g. central venous catheter, prosthetic heart valve) infections, infectious endocarditis, blood stream infections, bone, and joint infections (e.g. osteomyelitis, prosthetic joint, surgical site), central nervous system infections (e.g. meningitis, brain/spinal cord abscess, ventriculitis, hydrocephalus), respiratory tract infections (e.g. hospital-acquired pneumonia, ventilator-associated pneumonia), urinary tract infections, and gastrointestinal infections. The emergence and spread of multidrug resistant (MDR) MRSA clones has limited therapeutic options. Older agents such as vancomycin, linezolid and daptomycin and a variety of newer MRSA antimicrobials and combination therapy are available to treat serious MRSA infections.

AREAS COVERED

The authors discuss infections caused by MRSA as well as common older and newer antimicrobials and combination therapy for MRSA infections. A literature search of MRSA was performed via PubMed (up to September 2022), using the keywords: antimicrobial resistance; β-lactams; multidrug resistance, Staphylococcus aureus, vancomycin; glycolipopeptides.

EXPERT OPINION

Innovation, discovery, and development of new and novel classes of antimicrobial agents are critical to expand effective therapeutic options. The authors encourage the judicious use of antimicrobials in accordance with antimicrobial stewardship programs along with infection-control measures to minimize the spread of MRSA.

Eleven-Year surveillance of methicillin-resistant Staphylococcus aureus infections at an Academic Health Centre

INTRODUCTION

Methicillin-resistant Staphylococcus aureus (MRSA) is an important human pathogen associated with nosocomial and community infections. There is a continual focus on the epidemiology of this public health threat owing to the increase in its spread and rapid development of resistance.

AIM

We aimed to demonstrate the time trend of antibiotic resistance by describing the epidemiology of MRSA infections at an academic health centre.

METHODOLOGY

We retrospectively reviewed cases during an 11-year period (from January 2009 to December 2019) with positive cultures for MRSA from various clinical sites in King Fahad Hospital of the University, to understand their clinical and microbiological profiles. Screening and colonisation samples were excluded.

RESULTS

A total of 1338 MRSA isolates were identified, with an increasing trend from 5.2% to 14.5% during 2009-2019. Skin and soft tissue samples were the most common source (52.4%) of MRSA infections. Vancomycin activity remained stable against MRSA, and only one isolate showed resistance to linezolid (< 1%). A significant reduction in susceptibility to clindamycin (p = 0.003), trimethoprim-sulfamethoxazole (p = 0.001), and rifampin (p < 0.0001) was detected over the study period.

CONCLUSIONS

MRSA infections still represent a significant burden on healthcare systems. Our data support the need for constant local and regional surveillance to devise relevant protocols to manage MRSA infections. Empirical therapy needs to consider the changing antimicrobial susceptibility trends among MRSA isolates.

Clinical efficacy and safety of novel lipoglycopeptides in the treatment of acute bacterial skin and skin structure infections: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

This systematic review and meta-analysis aimed to investigate the clinical efficacy and safety of novel lipoglycopeptides in treating acute bacterial skin and skin structure infections (ABSSSIs).

RESEARCH DESIGN AND METHODS

PubMed, Embase, Cochrane Central Register of Controlled Trials, Turning Research into Practice, and ClinicalTrials.gov were searched from inception to 20 May 2021. Randomized controlled trials (RCTs) comparing the clinical efficacy and safety of lipoglycopeptides with other comparators in treating adult patients with ABSSSIs were included. The primary outcome was clinical response.

RESULTS

Eight RCTs (6416 patients; lipoglycopeptides: 3359, comparators: 3057) were enrolled. Clinical response rate was not significantly different between lipoglycopeptides and comparators at early-clinical-evaluation (odds ratio [95% confidence interval]: 1.01 [0.85-1.20], I² = 34%), end-of-treatment (0.94 [0.80-1.11], I² = 0%), and test-of-cure (1.05 [0.85-1.30], I² = 0%). Lipoglycopeptides showed a similar overall microbiological eradication rate (1.12 [0.90-1.38], I² = 21%) but a borderline higher microbiological eradication rate for methicillin-resistant Staphylococcus aureus (1.37 [1.00-1.86], I² = 0%) than the comparators. Lipoglycopeptides were not associated with a higher risk than comparators.

CONCLUSIONS

Lipoglycopeptides can achieve similar clinical and microbiological responses to other comparators in treating ABSSSIs. In addition, lipoglycopeptides are as tolerable as their comparators.

Anti-MRSA Cephalosporin versus Vancomycin-Based Treatment for Acute Bacterial Skin and Skin Structure Infection: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

This systematic review and meta-analysis of randomized controlled trials (RCTs) compared the clinical efficacy and safety of anti-MRSA cephalosporin and vancomycin-based treatment in treating acute bacterial skin and skin structure infections (ABSSSIs). PubMed, Embase, Cochrane Central Register of Controlled Trials, Turning Research into Practice, and ClinicalTrials.gov databases were searched for relevant articles from inception to 15 June 2020. RCTs comparing the clinical efficacy and safety of anti-MRSA cephalosporin with those of vancomycin-based regimens in treating adult patients with ABSSSIs were included. The primary and secondary outcomes were clinical response at the test-of-cure assessments and risk of adverse events (AEs), respectively. Eight RCTs were enrolled. The clinical response rate was not significantly different between anti-MRSA cephalosporin and vancomycin-based treatments (odds ratio [OR], 1.05; 95% CI, 0.90–1.23; I² = 0%). Except for major cutaneous abscesses in which anti-MRSA cephalosporin-based treatment was associated with a lower clinical response rate than vancomycin-based treatment (OR, 0.62; 95% CI, 0.40–0.97; I² = 0%), other subgroup analyses according to the type of cephalosporin (ceftaroline or ceftobiprole), type of infection, and different pathogens did not show significant differences in clinical response. Anti-MRSA cephalosporin-based treatment was only associated with a higher risk of nausea than vancomycin-based treatment (OR, 1.41; 95% CI, 1.07–1.85; I² = 0%). In treating ABSSSIs, the clinical efficacy of anti-MRSA cephalosporin is comparable to that of vancomycin-based treatment, except in major cutaneous abscesses. In addition to nausea, anti-MRSA cephalosporin was as tolerable as vancomycin-based treatment.

Synthesis and Biological Evaluation of Amoxicillin Loaded Hybrid Material Composite Spheres Against Methicillin-Resistant Staphylococcus aureus

BACKGROUND

Incoherent use of antibiotics has led toward resistance in MRSA, becoming multidrug-resistant with a high rate of virulence in the community and hospital settings.

OBJECTIVE

Synergistic anti-MRSA activity was investigated in this study for hybrid material composite spheres of amoxicillin, Ag nanoparticles, and chitosan, which were prepared by one-step synthesis method, and various characterizations were performed.

METHODS

Antimicrobial-susceptibility assay on MRSA was achieved by disc diffusion and agar dilution techniques, while agar well diffusion was used for hybrid composite spheres. The in vitro and cytotoxicity studies were conducted on the skin abrasion mouse model and MTT assay on RD cell, respectively.

RESULTS

All isolates showed resistance to the tested antibiotics except vancomycin. MIC against MRSA showed high resistance with amoxicillin from 4 to 128 mg L^-1. The mean diameter of chitosan spheres and Ag nanoparticles was 02 mm and 277 nm, respectively. Morphology of spheres was uneven, varied, porous, and irregular in SEM, and Ag nanoparticles presence and formation was also seen in the micrograph. No substantial interface among drug, nanoparticles, and polymer was found in XRD, and IR showed characteristic peaks of all compounds in the formulation. The in vitro assay showed augmented anti-MRSA activity with amoxicillin loaded hybrid composite spheres (22-29 mm). A significant reduction in microbial burden (~6.5 log₁₀ CFU mL^-1) was seen in vivo with loaded hybrid composite spheres formulation. The MTT assay indicated no potential cytotoxicity with hybrid composite spheres.

CONCLUSION

The synergistic effect of Amoxycillin in the current study predicts a promising hybrid formulation with enhanced anti-MRSA activity.

Invasive Bacterial Infections in Infants Younger Than 60 Days With Skin and Soft Tissue Infections

OBJECTIVE

The objective of this study was to describe the frequency of invasive bacterial infections (IBIs) in young infants with skin and soft tissue infections (SSTIs) and the impact of IBI evaluation on disposition, length of stay (LOS), and cost.

METHODS

This retrospective (2009-2014) cohort study used data from 35 children's hospitals in the Pediatric Health Information System. We included infants younger than 60 days who presented to an emergency department (ED) with SSTI. Invasive bacterial infection was defined as bacteremia/sepsis, bone/joint infection, or bacterial meningitis. Readmission and return ED visits within 30 days were evaluated to identify missed IBIs for infants.

RESULTS

A total of 2734 infants were included (median age, 33 days; interquartile range [IQR], 21-44); 62% were hospitalized. Invasive bacterial infection was identified in 2%: bacteremia (1.8%), osteomyelitis (0.1%), and bacterial meningitis (0.1%). Hospitalization occurred in 78% of infants with blood cultures, 95% with cerebrospinal fluid cultures, and 23% without cultures. Median hospitalization LOS was 2 days (IQR, 1-3). Median cost was US $4943 for infants with cerebrospinal fluid cultures (IQR, US $3475-6780) compared with US $419 (IQR, US $215-1149) for infants without IBI evaluations (P < 0.001). Five infants (0.2%) returned to the ED within 30 days with new IBI diagnoses (4 bacteremia, 1 meningitis).

CONCLUSIONS

Invasive bacterial infection occurs infrequently in infants younger than 60 days who present to children's hospital EDs with SSTI. Bacteremia is the most common IBI. More extensive evaluation for IBI is associated with increased rate of admission, LOS, and cost. Further studies are needed to evaluate the safety of a limited IBI evaluation in young infants with SSTI.

Understanding Pediatric Drug Lag Time: Review of Selected Drug Package Inserts

The wait for a pharmaceutical drug to become approved by the FDA for pediatrics lasts approximately 8 years longer than that for adults. One of the reasons given is the concern that simultaneous pediatric and adult trials may affect licensing in adults. We reviewed drug package inserts obtained from the FDA database for 5 selected agents for the years prior to and after being FDA approved for pediatric use. There were no new contraindications, warnings, or adverse events identified during pediatric clinical trials that would have put adult licensure at risk if approval was obtained in parallel for pediatric populations. The few changes in the package inserts in those years were due to ongoing adult clinical trials and post-marking experience in adults. The concern that pediatric trials might affect adult licensure does not appear to be justifiable.

Amplify antimicrobial photo dynamic therapy efficacy with poly-beta-amino esters (PBAEs)

Light-activated antimicrobial agents (photosensitisers) are promising alternatives to antibiotics for the treatment of skin infections and wounds through antimicrobial photo dynamic therapy (aPDT); utilisation of this technique is still restricted by general low efficacy requiring long exposure time (in the order of tens of minutes) that make the treatment very resource intensive. We report for the first time the possibility of harvesting the cell penetrating properties of poly-beta-amino esters (PBAEs) in combination with toluidine blue O (TBO) to shorten aPDT exposure time. Candidates capable of inactivation rates 30 times quicker than pure TBO were discovered and further improvements through PBAE backbone optimisation could be foreseen. Efficacy of the complexes was PBAE-dependent on a combination of TBO uptake and a newly discovered and unexpected role of PBAEs on reactive species production. Chemometric approach of partial least square regression was employed to assess the critical PBAE properties involved in this newly observed phenomenon in order to elicit a possible mechanism. The superior antimicrobial performance of this new approach benefits from the use of well established, low-cost and safe dye (TBO) coupled with inexpensive, widely tested and biodegradable polymers also known to be safe. Moreover, no adverse cytotoxic effects of the PBAEs adjuvated TBO delivery have been observed on a skin cells in vitro model demonstrating the safety profile of this new technology.

Temporal and seasonal trends of hospitalization and mortality associated with necrotizing fasciitis: A retrospective study of 12 years (2002-2013)

Background: Necrotizing fasciitis (NF) is a rare but aggressive infection that affects the superficial fascia and progressively destroys the tissue between the skin and underlying muscles. It is a surgical emergency with significant morbidity and mortality. This study aimed to explore the temporal and seasonal trends in NF infection in Qatar. Methods: A total of 327 patients diagnosed with NF, aged ≥ 18 years, and admitted to the Hamad General Hospital, Qatar, in 2002-2013 were retrospectively reviewed. The hospitalization and mortality rates in the general population in Qatar and the case fatality rate (CFR) were calculated for each year. The patients were grouped into summer, autumn, winter, and spring admissions based on their admission dates. Seasonality was studied by comparing the characteristics, bacteriological status, and outcomes of the patients admitted in different seasons. Results: The hospitalization rate of NF in Qatar was 2.9 per 100,000 population; in the study duration, this rate decreased from 2.8 to 1.6 per 100,000 population in 2002 and 2013, respectively. The mortality rate among NF cases increased from 1.9 to 3.6 per million population, and the CFR increased from 6.7 to 23 per 100 admissions in the same duration. No temporal trends in the hospitalization and mortality rates or CFR were evident in the study duration. Polybacterial infections were higher in autumn than in other seasons. Monobacterial Gram-positive infections were higher in spring than in other seasons, and monobacterial Gram-negative infections were higher in summer than in other seasons (p = 0.02). However, seasonality was not evident after further analysis in terms of species, severity, complications, length of hospital stays, and CFR in patients with NF. Conclusion: No clear trend or seasonality was observed in terms of outcomes; however, seasonality in NF-causing bacteria was evident, as polybacterial infections were significantly higher in autumn than in other seasons, whereas monobacterial infections were more frequent in spring and summer than in other seasons. However, the severity of infections, length of hospital stay, and mortality did not significantly vary. Further microbiological studies are needed to obtain confirmatory data regarding the temporal and seasonal trends of NF.

The extreme drug resistance (XDR) Staphylococcus aureus strains among patients: A retrospective study

The objective of the present work was to observe and profile various antibiotic resistant strains of Staphylococcus aureus and highlight the need for continuous surveillance. Data regarding antibiotic-resistant S. aureus strains isolated and identified at the Medical Microbiology Department, King Khalid Hospital, Riyadh was obtained. Bacterial isolates were collected from several sites of infections in patients and an evaluation of susceptibility were carried out using a fully automated Vitek2 system. Relative frequency (%), odds ratios and Ward's minimum variance were calculated. The results showed that wounds were a source of more than 40% of the S. aureus (MRSA) strains that have ability to resist methicillin, and more than 45% of the methicillin-susceptible S. aureus (non-MRSA) strains. 40% of the isolates were MRSA (N = 251), and all MRSA strains were sensitive to vancomycin, daptomycin, teicoplanin, tigecycline, nitrofurantoin, and itraconazole while all non-MRSA (N = 338) strains were sensitive to vancomycin, cefoxitin, daptomycin, gentamicin, oxacillin, teicoplanin, tigecycline, and mupirocin. Strength of association between antibiotic-resistant S. aureus strains and source of samples (site of infection) was established. The study concluded that S. aureus strains had developed resistance towards 20 (for non-MRSA) and 22 (for MRSA) of the antibiotics tested. All MRSA strains were non-sensitive to amoxicillin/clavulanate, ampicillin cefoxitin, cefazolin, imipenem, oxacillin, and penicillin.

Reducing Unnecessary Testing in Uncomplicated Skin and Soft Tissue Infections: A Quality Improvement Approach

OBJECTIVES

Skin and soft tissue infections are common pediatric diagnoses with substantial costs. Recent studies suggest blood cultures are not useful in management of uncomplicated skin and soft tissue infections (uSSTIs). Complete blood cell count, erythrocyte sedimentation rate, and C-reactive protein are also of questionable value. We aimed to decrease these tests by 25% for patients with uSSTIs admitted to the pediatric hospital medicine service within 3 months.

METHODS

An interdisciplinary team led a quality improvement (QI) project. Baseline assessment included review of the literature and 12 months of medical records. Key stakeholders identified drivers that informed the creation of an electronic order set and development of a pediatric hospital medicine-emergency department collaborative QI project. The primary outcome measure was mean number of tests per patient encounter. Balancing measures included unplanned readmissions and missed diagnoses.

RESULTS

Our baseline-year rate was 3.4 tests per patient encounter (573 tests and 169 patient encounters). During the intervention year, the rate decreased by 35% to 2.2 tests per patient encounter (286 tests and 130 patient encounters) and was sustained for 14 months postintervention. There were no unplanned readmissions or missed diagnoses for the study period. Order set adherence was 80% (83 out of 104) during the intervention period and sustained at 87% postintervention.

CONCLUSIONS

Our interdisciplinary team achieved our aim, reducing unnecessary laboratory testing in patients with an uSSTI without patient harm. Awareness of local culture, creation of an order set, defining appropriate patient selection and testing indications, and implementation of a collaborative QI project helped us achieve our aim.

Impact of Decolonization Protocols and Recurrence in Pediatric MRSA Skin and Soft-Tissue Infections

BACKGROUND

Methicillin-resistant staphylococcus aureus (MRSA) colonization is associated with the development of skin and soft-tissue infection in children. Although MRSA decolonization protocols are effective in eradicating MRSA colonization, they have not been shown to prevent recurrent MRSA infections. This study analyzed the prescription of decolonization protocols, rates of MRSA abscess recurrence, and factors associated with recurrence.

MATERIALS AND METHODS

This study is a single-institution retrospective review of patients ≤18 y of age diagnosed with MRSA culture-positive abscesses who underwent incision and drainage (I&D) at a tertiary-care children's hospital. The prescription of an MRSA decolonization protocol was recorded. The primary outcome was MRSA abscess recurrence.

RESULTS

Three hundred ninety-nine patients with MRSA culture-positive abscesses who underwent I&D were identified. Patients with previous history of abscesses, previous MRSA infection groin/genital region abscesses, higher number of family members with a history of abscess/cellulitis or MRSA infection, and I&D by a pediatric surgeon were more likely to be prescribed decolonization. Decolonized patients did not have lower rates of recurrence. Recurrence was more likely to occur in patients with previous abscesses, previous MRSA infection, family history of abscesses, family history of MRSA infection, Hispanic ethnicity, and those with fever on admission.

CONCLUSIONS

MRSA decolonization did not decrease the rate of recurrence of MRSA abscesses in our patient cohort. Patients at high risk for MRSA recurrence such as personal or family history of abscess or MRSA infection, Hispanic ethnicity, or fever on admission did not benefit from decolonization.

A Spatial Analysis of Health Disparities Associated with Antibiotic Resistant Infections in Children Living in Atlanta (2002-2010)

Background

Antibiotic resistant bacteria like community-onset methicillin resistant Staphylococcus aureus (CO-MRSA) have continued to cause infections in children at alarming rates and are associated with health disparities. Geospatial analyses of individual and area level data can enhance disease surveillance and identify socio-demographic and geographic indicators to explain CO-MRSA disease transmission patterns and risks.

Methods

A case control epidemiology approach was undertaken to compare children with CO-MRSA to a noninfectious condition (unintentional traumatic brain injury (uTBI)). In order to better understand the impact of place based risks in developing these types of infections, data from electronic health records (EHR) were obtained from CO-MRSA cases and compared to EHR data from controls (uTBI). US Census data was used to determine area level data. Multi-level statistical models were performed using risk factors determined a priori and geospatial analyses were conducted and mapped.

Results

From 2002-2010, 4,613 with CO-MRSA and 34,758 with uTBI were seen from two pediatric hospitals in Atlanta, Georgia. Hispanic children had reduced odds of infection; females and public health insurance were more likely to have CO-MRSA. Spatial analyses indicate significant 'hot spots' for CO-MRSA and the overall spatial cluster locations, differed between CO-MRSA cases and uTBI controls.

Conclusions

Differences exist in race, age, and type of health insurance between CO-MRSA cases compared to noninfectious control group. Geographic clustering of cases is distinct from controls, suggesting placed based factors impact risk for CO-MRSA infection.

Staphylococcus aureus

Staphylococcus aureus is a bacterium that can cause a variety of illnesses through suppurative or nonsuppurative (toxin-mediated) means. S aureus is a common cause of skin and skin structure infections as well as osteoarticular infections in the pediatric population. S aureus is also identified in cases of septicemia, infective endocarditis, pneumonia, ocular infections, and central nervous system infections. To design appropriate empirical therapy, pediatricians should be knowledgeable about the resistance patterns of S aureus in their communities, including methicillin and clindamycin resistance. This article reviews the microbiology, colonization and transmission, and antibiotic resistance of and clinical diseases caused by S aureus.

S. aureus Infections in Chicago, 2006-2014: Increase in CA MSSA and Decrease in MRSA Incidence

OBJECTIVE To examine trends in Staphylococcus aureus infections in adults and children at a single academic center in 2006-2014. DESIGN Retrospective cohort study. SETTING Inpatient, outpatient, and emergency department settings in a private, tertiary referral center. PATIENTS Patients with an infection culture that grew S. aureus in January 1, 2006, through March 31, 2014. METHODS The first isolate per year for each patient was classified as community-associated (CA-), healthcare-associated (HA-), or HA-community-onset S. aureus. The incidence density of S. aureus, methicillin-susceptible S. aureus (MSSA), and methicillin-resistant S. aureus (MRSA) infections were calculated per quarter year. RESULTS Overall, 5,491 MRSA and 5,398 MSSA isolates were included. MRSA infections decreased by an average of 5.2% annually (P<.001). MRSA skin and soft-tissue infection (SSTI) incidence density decreased in adults (-3.5%; P<.001) and children (-2.9%; P=.004). MSSA infections at all anatomic sites increased by an average of 1.9% annually (P=.007) in adults and decreased 5.1% annually (P<.001) in children. MSSA SSTI incidence density increased in adults (+3.8%; P<.001) and children (+5.6%; P<.001). For MRSA and MSSA SSTI isolates, susceptibility to tetracycline and clindamycin decreased significantly. CONCLUSIONS In 2006-2014, MRSA SSTI incidence decreased among children and adults. MSSA SSTI incidence density increased in children and adults, suggesting that current empiric SSTI treatment recommendations may not be optimal. Adults experienced an overall increase in MSSA infections, which may prompt consideration of the need for horizontal infection control practices to decrease MSSA infection risk. Infect Control Hosp Epidemiol 2017;38:1226-1234.

Clinico-bacteriological profile of primary pyodermas in Kashmir: a hospital-based study

Pyodermas are a common group of infectious dermatological conditions on which few studies have been conducted. This study aimed to characterise the clinical and bacteriological profile of pyodermas, and to determine the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) infection in primary pyodermas in a dermatology outpatient department in Kashmir. Methods We conducted a hospital based cross-sectional study in the outpatient Department of Dermatology, Sexually Transmitted Diseases and Leprosy of Shri Maharaja Hari Singh Hospital, Srinagar, Jammu and Kashmir, India. Patients presenting with primary pyodermas were included in the study. A detailed history and complete physical and cutaneous examination was carried out along with microbiological testing to find aetiological microorganisms and their respectiveantimicrobial susceptibility patterns. Antimicrobial susceptibility testing, including that for methicillin resistance, was carried out by standard methods as outlined in the current Clinical and Laboratory Standards Institute guidelines. Results In total, 110 patients were included; the age of the study population ranged from 3 to 65 years (mean age 28 years); 62% were male. Poor personal hygiene was noted in 76 (69%). Furunculosis (56; 51%) was the most common clinical presentation. Staphylococcus aureus was isolated in 89 (81%) of cases, and MRSA formed 54/89 (61%) of Staphylococcus aureus isolates. All MRSA strains were sensitive to vancomycin. Conclusion The prevalence of MRSA was high in this sample of communityacquired primary pyodermas. It is therefore important to monitor the changing trends in bacterial infection and their antimicrobial susceptibility patterns and to formulate a definite antibiotic policy which may be helpful in decreasing the incidence of MRSA infection.

Using quality improvement methods to change surgical practice: a case example of pediatric soft-tissue abscesses

BACKGROUND

Surgical treatments of soft-tissue abscesses (STAs) include packing and ring drain (RD) and straight drain (SD) placement. Potential benefits of SDs include a single incision, less scarring, and no need for a follow-up appointment. We used a multidisciplinary quality improvement (QI) process to promote surgeon adoption of an STA drainage technique to improve efficiency and quality of care.

SUBJECTS AND METHODS

Outcome measures included the proportion of STAs drained using SDs, the number of postoperative clinic visits, the proportion of patients requiring follow-up with a pediatric surgeon and other providers, and the postoperative complication rate, defined as need for an additional drainage procedure.

RESULTS

After beginning the QI initiative, the proportion of STAs drained by SDs increased from 23% to 78% (P < .00001) and the proportion of patients requiring a surgical follow-up clinic appointment decreased from 71% to 32% (P < .00001). The mean number of surgical clinic visits per patient decreased from 0.79 to 0.39 visits per patient (P < .00001). Complication rates were similar between drain types (RD: 2.4%; SD: 1.7%; P = .57). This QI initiative produced a rapid sustained shift in surgeon practice with increased use of SDs, decreased number of follow-up visits, and no increase in complications.

Decreasing Incidence of Skin and Soft Tissue Infections With a Seasonal Pattern at an Academic Medical Center, 2006-2014

The incidence of SSTIs at University of Chicago Medicine decreased significantly in children and adults with seasonal variation, peaking during the summer months. This suggests a reversal of the massive increase in SSTI incidence after 2000 in the U.S.

Background. The incidence of skin and soft tissue infections (SSTIs) in the United States increased sharply after 2000 with the emergence of USA300 methicillin-resistant Staphylococcus aureus. We examined trends in SSTI incidence in 2006–2014 at the University of Chicago Medicine (UCM).

Methods. Data were obtained for patient encounters at UCM with an International Classification of Diseases, Ninth Revision-coded SSTI diagnosis between January 1, 2006 and March 31, 2014. Incidence density was calculated per 1000 encounters by quarter and year. Encounters were stratified by inpatient, outpatient clinic and emergency department (ED) encounters and by age group, gender, and race. Poisson regression was used to assess change over time.

Results. In 2006–2014, data were collected for 38 201 SSTI-associated encounters among 31 869 subjects. Among all patients treated at UCM, there was a decrease of 1% per year in the incidence of SSTIs during 2006–2013, with an overall decrease of 16%. There was a significant decrease in SSTI-related encounters among inpatients (rate ratio [RR] = 0.97; 95% confidence interval [CI], .96–.98), ED patients (RR = 0.98; 95% CI, .97–.98), adults (RR = 0.98; 95% CI, .97–.98), children (RR = 0.96; 95% CI, .95–.97), and African Americans (RR = 0.99; 95% CI, .98–.99). There was an annual seasonal trend, with the peak incidence occurring during the late summer.

Conclusions. The incidence of SSTIs at UCM decreased in children and adults with seasonal variation, peaking during the summer months. This suggests a reversal of the massive increase in SSTI incidence in the United States after 2000.

Changing Susceptibility of Staphylococcus aureus in a US Pediatric Population

BACKGROUND

Staphylococcus aureus is a major cause of infection in both adult and pediatric populations. After several decades of increasing prevalence, the proportion of S aureus infections due to methicillin-resistant S aureus has been reported to be in decline in adults. Data for similar changes in pediatric populations are limited.

METHODS

Evaluation of S aureus susceptibility data for pediatric patients receiving care in the US Military Health System was performed. Microbiology and demographic data were collected for years 2005 through 2014. Trends in antibiotic susceptibility results were evaluated. Clinical and demographic characteristics were explored to assess for association with antibiotic susceptibilities.

RESULTS

In this study, 41 745 S aureus isolates from 39 207 pediatric patients were included. An overall increase in susceptibility of isolates to oxacillin was noted over this 10-year period; with over 60% of isolates oxacillin-susceptible in 2014. S aureus susceptibility to clindamycin declined over the study period; notably methicillin-susceptible S aureus susceptibility to clindamycin declined from 90% to 83% (P < .0001). Differences in oxacillin susceptibility between US regions decreased over time.

CONCLUSIONS

Similar to recent trends seen in adults, the proportion of pediatric S aureus infections secondary to methicillin-resistant S aureus appear to be decreasing, as is variability in US geographical resistance rates. Increasing clindamycin resistance among methicillin-susceptible S aureus should raise caution in the use of empirical clindamycin in presumed S aureus infection. Clinicians should be aware of regional susceptibility patterns when choosing empirical regimens.

Infection in cystic fibrosis: impact of the environment and climate

In many countries numbers of adults with cystic fibrosis (CF) exceed that of children, with median survival predicted to surpass 50 years. Increasing longevity is, in part, due to intensive therapies including eradication of early infection and suppressive therapies and pulmonary exacerbations. Initial infections with common CF pathogens are thought to arise from the natural environment. We review the impact of climate and environment on infection in CF. Specifically, several studies indicate that higher ambient temperatures, proximity to the equator and the summer season may be linked to the increased prevalence of Pseudomonas aeruginosa in people with CF. The environment may also play an important role in the acquisition of Gram negative organisms other than P. aeruginosa. There is emerging data suggesting that climatic and environmental factors are likely to impact on the risk of infection with NTM and fungi in people which are found extensively throughout the natural environment.

Staphylococcus aureus-Associated Skin and Soft Tissue Infections: Anatomical Localization, Epidemiology, Therapy and Potential Prophylaxis

Skin and soft tissue infections (SSTIs) are among the most common infections worldwide. They range in severity from minor, self-limiting, superficial infections to life-threatening diseases requiring all the resources of modern medicine. Community (CA) and healthcare (HA) acquired SSTIs are most commonly caused by Staphylococcus aureus . They have variable presentations ranging from impetigo and folliculitis to surgical site infections (SSIs). Superficial SSTIs may lead to even more invasive infections such as bacteraemia and osteomyelitis. Here we describe the anatomical localization of the different SSTI associated with S. aureus, the virulence factors known to play a role in these infections, and their current epidemiology. Current prevention and treatment strategies are also discussed. Global epidemiological data show increasing incidence and severity of SSTIs in association with methicillin-resistant S. aureus strains (MRSA). CA-SSTIs are usually less morbid compared to other invasive infections caused by S. aureus, but they have become the most prevalent, requiring a great number of medical interventions, extensive antibiotic use, and therefore a high cost burden. Recurrence of SSTIs is common after initial successful treatment, and decolonization strategies have not been effective in reducing recurrence. Furthermore, decolonization approaches may be contributing to the selection and maintenance of multi-drug resistant strains. Clinical studies from the early 1900s and novel autovaccination approaches suggest an alternative strategy with potential effectiveness: using vaccines to control S. aureus cutaneous infections.

Outcomes After Skin and Soft Tissue Infection in Infants 90 Days Old or Younger

BACKGROUND AND OBJECTIVES

Skin and soft tissue infections (SSTIs) are an increasingly common cause of pediatric hospital visits among infants. The optimal evaluation strategy for younger infants with SSTI is unknown because there is little information about outcomes including risks of concomitant bacterial infections and treatment failure. This study was designed to determine rates of concomitant invasive bacterial infection and hospital revisits for treatment failure as well as factors associated with treatment failure in infants presenting with SSTI.

METHODS

Retrospective study of patients≤90 days of age who received care from the 22 emergency departments and hospitals in the Intermountain Healthcare system from July 1, 2004 to December 31, 2011, with a primary discharge diagnosis of SSTI. Concomitant bacterial infections were defined as urinary tract infection (UTI; culture-confirmed) or invasive bacterial infection (IBI; culture-confirmed bacteremia and/or meningitis). Treatment failure was defined as any unplanned change in care at hospital revisit within 14 days of discharge.

RESULTS

The study included 172 infants; 29 (17%) were febrile, and 91 (53%) had ≥1 sterile site culture performed. One case of bacteremia in a febrile infant was identified giving an overall proportion with UTI/IBI of 0.58% (95% confidence interval 0.01%-3.2%). Sixteen infants (9.3%; 95% confidence interval 5.4%-14.7%) returned for treatment failure. Perianal location (P=.03) and private insurance status (P=.01) were associated with more treatment failures compared with other locations or payer types. No patients returned for missed UTI/IBI.

CONCLUSIONS

Concomitant bacterial infections were rare in infants with SSTI, with none identified in afebrile infants. Treatment failure of SSTI leading to hospital revisit was common.

Application of a methicillin-resistant Staphylococcus aureus risk score for community-onset pneumonia patients and outcomes with initial treatment

BACKGROUND

Community-onset (CO) methicillin-resistant Staphylococcus aureus (MRSA) pneumonia is an evolving problem, and there is a great need for a reliable method to assess MRSA risk at hospital admission. A new MRSA prediction score classifies CO-pneumonia patients into low, medium, and high-risk groups based on objective criteria available at baseline. Our objective was to assess the effect of initial MRSA therapy on mortality in these three risk groups.

METHODS

We conducted a retrospective cohort study using data from the Veterans Health Administration (VHA). Patients were included if they were hospitalized with pneumonia and received antibiotics within the first 48 h of admission. They were stratified into MRSA therapy and no MRSA therapy treatment arms based on antibiotics received in the first 48 h. Multivariable logistic regression was used to adjust for potential confounders.

RESULTS

A total of 80,330 patients met inclusion criteria, of which 36% received MRSA therapy and 64% did not receive MRSA therapy. The majority of patients were classified as either low (51%) or medium (47%) risk, with only 2% classified as high-risk. Multivariable logistic regression analysis demonstrated that initial MRSA therapy was associated with a lower 30-day mortality in the high-risk group (adjusted odds ratio 0.57; 95% confidence interval 0.42-0.77). Initial MRSA therapy was not beneficial in the low or medium-risk groups.

CONCLUSIONS

This study demonstrated improved survival with initial MRSA therapy in high-risk CO-pneumonia patients. The MRSA risk score might help spare MRSA therapy for only those patients who are likely to benefit.

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.

Shifting trends in the incidence of Pseudomonas aeruginosa septicemia in hospitalized adults in the United States from 1996-2010

BACKGROUND

Pseudomonas aeruginosa septicemia (PAS) is associated with high mortality rates and substantial resource utilization; however, the burden of PAS in the United States in recent years is unknown.

METHODS

This was a retrospective analysis of the U.S. National Hospital Discharge Surveys from 1996-2010. Adult patients with an ICD-9-CM code for PAS (038.43) were included. Incidence, in-hospital mortality, and hospital length of stay (LOS) for PAS discharges were reported. Incidence was calculated as PAS discharges per 10,000 total adult discharges.

RESULTS

Overall, 213,553 patients had a PAS discharge diagnosis during the study period. Patients had a median (interquartile range [IQR]) age of 69 (55-78) years and were predominately men (61%) and white (75%). PAS incidence declined from 6.5 per 10,000 in 1996 to 3.1 per 10,000 in 2001 and then increased to 6.5 per 10,000 in 2010. PAS incidence was highest in the Northeast (7.6 per 10,000) and lowest in the South (6.2 per 10,000). The overall mortality rate was 16%, but this ranged from 10%-26% over the study period. Median LOS was 10 (IQR, 6-19) days, and this varied over the study period (8-13 days).

CONCLUSIONS

The incidence of PAS has increased among hospitalized adults in the United States since 2001, with little evidence of improvement in mortality or LOS.

Subscapular Abscess in a Nine-Year-Old Female Patient: A Case Report

CASE

The subscapular space is a clinically concealed anatomic space where soft-tissue abscesses can form. To our knowledge, five cases of a subscapular abscess have been reported in the past thirty-four years, so there is little evidence available to guide treatment. We present a unique case of a spontaneous, subscapular abscess due to methicillin-resistant Staphylococcus aureus in a pediatric host, and we describe a surgical approach for adequate debridement.

CONCLUSION

The effective treatment of a subscapular abscess depends on an accurate, rapid diagnosis and effective surgical debridement. A modified Judet approach provides adequate access to the subscapular space for debridement.

The rise in Clostridium difficile infection incidence among hospitalized adults in the United States: 2001-2010

BACKGROUND

Clostridium difficile infection (CDI) incidence is a growing concern. This study provides national estimates of CDI over 10 years and identifies trends in mortality and hospital length of stay (LOS) among hospitalized adults with CDI.

METHODS

We conducted a retrospective analysis of the US National Hospital Discharge Surveys from 2001-2010. Eligible cases included adults aged ≥ 18 years discharged from a hospital with an ICD-9-CM diagnosis code for CDI (008.45). Data weights were used to derive national estimates. CDI incidence rates were depicted as CDI discharges per 1,000 total adult discharges.

RESULTS

These data represent 2.2 million adult hospital discharges for CDI over the study period. CDI incidence increased from 4.5 CDI discharges per 1,000 total adult discharges in 2001 to 8.2 CDI discharges per 1,000 total adult discharges in 2010. The overall in-hospital mortality rate was 7.1% for the study period. Mortality increased slightly over the study period, from 6.6% in 2001 to 7.2% in 2010. Median hospital LOS was 8 days (interquartile range, 4-14 days), and remained stable over the study period.

CONCLUSIONS

The incidence of CDI among hospitalized adults in the United States nearly doubled from 2001-2010. Furthermore, there is little evidence of improvement in patient mortality or hospital LOS.

The effect of statin therapy on the incidence of infections: a retrospective cohort analysis

BACKGROUND

Statins have been postulated to prevent infection through immunomodulatory effects.

OBJECTIVES

To compare the incidence of infections in statin users to that in nonusers within the same health care system.

METHODS

This was a retrospective cohort study of patients enrolled as Tricare Prime or Plus in the San Antonio military multimarket. Statin users were patients who received a statin for at least 3 months between October 1, 2004 and September 30, 2005. Nonusers were patients who did not receive a statin within the study period (October 1, 2003-September 30, 2009). Inpatient and outpatient International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) codes were used to determine the incidence of infections during the follow-up period (October 1, 2005-September 30, 2009) via multivariable regression analysis and time to infection via Cox regression analysis.

RESULTS

Of 45,247 patients who met the study criteria, 12,981 (29%) were statin users and 32,266 were nonusers. After adjustments for age, gender, Charlson Comorbidity Score, tobacco use, alcohol abuse/dependence, health care utilization and use of specific medication classes, statin use was associated with an increased incidence of common infections (odds ratio [OR]: 1.13; 95% confidence interval [CI]: 1.06-1.19) but not influenza or fungal infections (OR: 1.06, 95% CI: 0.80-1.39; OR: 0.97; 95% CI: 0.91-1.04, respectively). Time-to-first infection was similar in statin users and nonusers in all infection categories examined.

CONCLUSIONS

Statin use was associated with an increased incidence of common infections but not influenza or fungal infections. This study does not support a protective role of statins in infection prevention; however, the influence of potential confounders cannot be excluded.

Trends in catheter-associated urinary tract infections among a national cohort of hospitalized adults, 2001-2010

BACKGROUND

Catheter-associated urinary tract infections (CAUTIs) have become a major public health concern in the United States. This study provides national estimates of CAUTI incidence, mortality, and associated hospital length of stay (LOS) over a 10-year period.

METHODS

This was a retrospective analysis of the National Hospital Discharge Surveys from 2001 to 2010. Adults age ≥18 years with an International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) procedure code for urinary catheter placement or other major procedure were included. Urinary tract infections were identified by ICD-9-CM code. Data weights were applied to derive national estimates. Predictors of CAUTI were identified using a logistic regression model.

RESULTS

These data represent 70.4 million catheterized patients, 3.8 million of whom developed a CAUTI. The incidence of CAUTIs decreased from 9.4 cases/100 catheterizations in 2001 to 5.3 cases/100 catheterizations in 2010. Mortality in patients with a CAUTI declined from 5.4% in 2001 to 3.7% in 2010. Median (interquartile range [IQR]) hospital LOS also declined, from 9 days (IQR, 5-16 days) in 2001 to 7 days (IQR, 4-12 days) in 2010. Independent predictors of CAUTI included female sex, emergency hospital admission, transfer from another facility, and Medicaid payment (P < .0001 for all variables).

CONCLUSIONS

The incidence of CAUTIs in US hospitals declined over the study period. Furthermore, patients with these infections experienced lower hospital mortality and shorter hospital LOS.

Factors associated with high resource utilization in pediatric skin and soft tissue infection hospitalizations

OBJECTIVE

To describe factors associated with prolonged lengths of stay (LOS) and increased charges for pediatric skin and soft tissue infection (SSTI) hospitalizations.

METHODS

This study was a cross-sectional analysis of pediatric SSTI hospital discharges in 2009 within the Healthcare Cost and Utilization Project Kids' Inpatient Database. Outcomes were prolonged LOS (>75th percentile) and increased hospital charges (>75th percentile). Multivariate logistic regression controlling for patient and hospital level factors was conducted for 2009 data to assess associations among variables.

RESULTS

The 75th percentile for LOS was 3 days. Infants had higher odds of prolonged LOS than other age groups (<1 year: 1; 1-4 years: 0.70 [95% confidence interval (CI): 0.64-0.76]; 5-12 years: 0.69 [95% CI: 0.63-0.76]; 13-18 years: 1.01 [95% CI: 0.91-1.10]), as did all minority groups compared with white subjects (black subjects: 1.23 [95% CI: 1.09-1.38]; Hispanic subjects: 1.33 [95% CI: 1.20-1.47]; and other races: 1.30 [95% CI: 1.12-1.50]). Public payers compared with private payers (odds ratio: 1.17 [95% CI: 1.10-1.26]) also had increased odds of prolonged LOS. The 75th percentile for charges was $14 317. The adolescent-aged category had higher odds of charges >75th percentile compared with the age category <1 year (odds ratio: 1.54 [95% CI: 1.36-1.74]). All racial/ethnic minorities had higher odds of charges >75th percentile compared with white subjects (black subjects: 1.38 [95% CI: 1.17-1.62]; Hispanic subjects: 1.90 [95% CI: 1.59-2.26]; and other races: 1.26 [95% CI: 1.06-1.50]).

CONCLUSIONS

Vulnerable populations, including infants, racial/ethnic minorities, and publicly insured children, had higher odds of increased resource utilization during hospitalizations for SSTIs. The findings of this study provide potential targets for future preventive and public health interventions.

Increasing incidence and sociodemographic variation in community-onset Staphylococcus aureus skin and soft tissue infections in New Zealand children

We analyzed all cases of community-onset Staphylococcus aureus skin and soft tissue infection in children presenting to our hospital between 2007 and 2010. A total of 1860 children were included. There was significant sociodemographic disparity, with the incidence disproportionately higher in Maori and Pacific Island children residing in deprived areas.

Update on Epidemiology and Treatment of MRSA Infections in Children

In 2000-10 the epidemiology of pediatric MRSA infections in the United States was transformed with an epidemic of CA-MRSA infections. We review the epidemiology of MRSA in the community and in the health care setting, including intensive care units, among infants and CF patients, and in households as well as the impact that the CA-MRSA epidemic has had on hospitalization with MRSA infections. Risk factors for carriage, transmission, and initial and recurrent infection with MRSA are discussed. New studies on the treatment of pediatric MRSA infections and on the efficacy of MRSA decolonization are reviewed.

Trends in ophthalmic manifestations of methicillin-resistant Staphylococcus aureus (MRSA) in a northern California pediatric population

PURPOSE

To determine pediatric clinical trends of ocular and periocular methicillin-resistant Staphylococcus aureus (MRSA) in a large northern California healthcare system.

METHODS

This study was a retrospective cross-sectional review of all pediatric cases (aged 0-18) with culture-positive ophthalmic MRSA isolates identified between January 2002 and December 2009. Medical record review included history, presentation, infection site, acquisition (community or nosocomial), antibiotic sensitivity/resistance, treatment, and clinical outcome. Incidence was classified by year, sex, and age. Parameters were analyzed for statistical significance by trend and χ(2) analysis.

RESULTS

A total of 399 ocular and periocular MRSA cases were included. Cases trended upward from 2002 to 2009, peaking in 2006. Of the 137 pediatric cases (0-18 years), 58% were community acquired. Conjunctivitis was the predominant presentation (40%), followed by stye/chalazion (25%), orbital cellulitis/abscess (19%), dacryocystitis (11%) and brow abscess (3%). Significant predictors for ocular infection with MRSA included male sex (61%), neonates (38%), and multiple infection sites on the body (38%). Resistance was high to bacitracin (80.9%) and ofloxacin (48.3%) but remained low for trimethoprim/sulfamethoxazole (8.7%). Topical therapy was effective in 29% of cases; oral antibiotics, in 47%. Intravenous therapy was required in 12% of cases and incision/drainage or surgery in 19%. Initial oral antibiotic treatment, primarily cephalosporins (24%), was ineffective in 37% of patients. There was a significant increase in resistance to antibiotic therapy (P < 0.001) during the study period. No patients developed permanent visual impairment.

CONCLUSIONS

Pediatric ocular and periocular MRSA is increasing in incidence and resistance in our patient population. Outcomes can be improved by early recognition, proper antibiotic selection, and obtaining cultures and sensitivities when resistant or severe ocular infections are present.

Incidence, microbiology, and patient characteristics of skin and soft-tissue infections in a U.S. population: a retrospective population-based study

Background

Skin and soft tissue infections (SSTIs) are commonly occurring infections with wide-ranging clinical manifestations, from mild to life-threatening. There are few population-based studies of SSTIs in the period after the rapid increase in community-acquired methicillin-resistant Staphyloccus aureus (MRSA).

Methods

We used electronic databases to describe the incidence, microbiology, and patient characteristics of clinically-diagnosed skin and soft tissue infections (SSTIs) among members of a Northern California integrated health plan. We identified demographic risk factors associated with SSTIs and MRSA infection.

Results

During the three-year study period from 2009 to 2011, 376,262 individuals experienced 471,550 SSTI episodes, of which 23% were cultured. Among cultured episodes, 54% were pathogen-positive. Staphylococcus aureus (S. aureus) was isolated in 81% of pathogen-positive specimens, of which nearly half (46%) were MRSA. The rate of clinically-diagnosed SSTIs in this population was 496 per 10,000 person-years. After adjusting for age group, gender, race/ethnicity and diabetes, Asians and Hispanics were at reduced risk of SSTIs compared to whites, while diabetics were at substantially higher risk compared to non-diabetics. There were strong age group by race/ethnicity interactions, with African Americans aged 18 to <50 years being disproportionately at risk for SSTIs compared to persons in that age group belonging to other race/ethnicity groups. Compared to Whites, S. aureus isolates of African-Americans and Hispanics were more likely to be MRSA (Odds Ratio (OR): 1.79, Confidence Interval (CI): 1.67 to 1.92, and, OR: 1.24, CI: 1.18 to 1.31, respectively), while isolates from Asians were less likely to be MRSA (OR: 0.73, CI: 0.68 to 0.78).

Conclusions

SSTIs represent a significant burden to the health care system. The majority of culture-positive SSTIs were caused by S. aureus, and almost half of the S. aureus SSTIs were methicillin-resistant. The reasons for African-Americans having a higher likelihood, and Asians a lower likelihood, for their S. aureus isolates to be methicillin-resistant, should be further investigated.

Use of nitric oxide nanoparticulate platform for the treatment of skin and soft tissue infections

The incidence of skin and soft tissue infections (SSTI) due to multi‐drug resistant pathogens is increasing. The concomitant increase in antibiotic use along with the ease with which organisms develop mechanisms of resistance have together become a medical crisis, underscoring the importance of developing innovative and effective antimicrobial strategies. Nitric oxide (NO) is an endogenously produced molecule with many physiologic functions, including broad spectrum antimicrobial activity and immunomodulatory properties. The risk of resistance to NO is minimized because NO has multiple mechanisms of antimicrobial action. NO's clinical utility has been limited largely because it is highly reactive and lacks appropriate vehicles for storage and delivery. To harness NO's antimicrobial potential, a variety exogenous NO delivery platforms have been developed and evaluated, yet limitations preclude their use in the clinical setting. Nanotechnology represents a paradigm through which these limitations can be overcome, allowing for the encapsulation, controlled release, and focused delivery of NO for the treatment of SSTI. WIREs Nanomed Nanobiotechnol 2013. doi: 10.1002/wnan.1230

This article is categorized under: 1

Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease

2

Nanotechnology Approaches to Biology > Nanoscale Systems in Biology

Is there a relationship between hygiene practices and skin and soft tissue infections in diapered children?

OBJECTIVES

The perineal and gluteal regions are the most frequent areas of skin and soft tissue infection (SSTI) in diapered children. No studies have investigated the relationship between perineal and general hygiene practices and SSTIs in this population. This study was conducted to evaluate this relationship.

METHODS

A cross-sectional observational study was conducted in an urban pediatric emergency department. Subjects were recruited into 3 study groups as follows: gluteal/perineal SSTIs (SSTI), diaper dermatitis (DD), or healthy normal skin (NS). Survey responses were analyzed for significance followed by a clinically oriented staged regression to model predictors of SSTI compared with the NS and DD groups.

RESULTS

There were 100 subjects in the SSTI, 206 in the NS, and 151 in the DD groups. Race was the only demographic characteristic that differed between the groups. After adjustment for race, no day care attendance, history of SSTI, household contact with SSTI history, and higher propensity for diaper rash were associated with SSTI compared with NS. Regression results comparing SSTI to DD revealed no day care attendance, history of SSTI, household contact with SSTI history, less sensitive skin, and less diaper cream use to be predictors of SSTI.

CONCLUSIONS

Perineal and general hygiene practices were not significantly different between children with SSTI compared with children with NS or DD. Based on the results of this study, further prospective studies should evaluate diaper hygiene practices that prevent DD and subsequent SSTIs, the preventative role of day care attendance, and effective interventions that minimize the risk of recurrent SSTIs.

Clinical and molecular epidemiology of methicillin-resistant Staphylococcus aureus in New Zealand: rapid emergence of sequence type 5 (ST5)-SCCmec-IV as the dominant community-associated MRSA clone

The predominant community-associated MRSA strains vary between geographic settings, with ST8-IV USA300 being the commonest clone in North America, and the ST30-IV Southwest Pacific clone established as the dominant clone in New Zealand for the past two decades. Moreover, distinct epidemiological risk factors have been described for colonisation and/or infection with CA-MRSA strains, although these associations have not previously been characterized in New Zealand. Based on data from the annual New Zealand MRSA survey, we sought to describe the clinical and molecular epidemiology of MRSA in New Zealand. All non-duplicate clinical MRSA isolates from New Zealand diagnostic laboratories collected as part of the annual MRSA survey were included. Demographic data was collected for all patients, including age, gender, ethnicity, social deprivation index and hospitalization history. MRSA was isolated from clinical specimens from 3,323 patients during the 2005 to 2011 annual surveys. There were marked ethnic differences, with MRSA isolation rates significantly higher in Māori and Pacific Peoples. Over the study period, there was a significant increase in CA-MRSA, and a previously unidentified PVL-negative ST5-IV spa t002 clone replaced the PVL-positive ST30-IV Southwest Pacific clone as the dominant CA-MRSA clone. Of particular concern was the finding of several successful and virulent MRSA clones from other geographic settings, including ST93-IV (Queensland CA-MRSA), ST8-IV (USA300) and ST772-V (Bengal Bay MRSA). Ongoing molecular surveillance is essential to prevent these MRSA strains becoming endemic in the New Zealand healthcare setting.

A population-based study of the epidemiology and clinical features of methicillin-resistant Staphylococcus aureus infection in Pennsylvania, 2001-2010

No U.S. general population-based study has characterized the epidemiology and risk factors, including skin and soft tissue infection (SSTI), for healthcare-associated (HA) and community-associated (CA) methicillin-resistant Staphylococcus aureus (MRSA). We estimated the incidence of HA- and CA-MRSA and SSTI over a 9-year period using electronic health record data from the Geisinger Clinic in Pennsylvania. MRSA cases were frequency-matched to SSTI cases and controls in a nested case-control analysis. Logistic regression was used to assess risk factors, while accounting for antibiotic administration. We identified 1713 incident CA- and 1506 HA-MRSA cases and 78 216 SSTI cases. On average, from 2005 to 2009, the annual incidence of CA-MRSA increased by 34%, HA-MRSA by 7%, and SSTI by 4%. Age, season, community socioeconomic deprivation, obesity, smoking, previous SSTI, and antibiotic administration were identified as independent risk factors for CA-MRSA.

Methicillin-resistant staphylococci: implications for our food supply?

Food-borne intoxication, caused by heat-stable enterotoxins produced by Staphylococcus aureus, causes over 240,000 cases of food-borne illness in the United States annually. Other staphylococci commonly associated with animals may also produce these enterotoxins. Foods may be contaminated by infected food handlers during slaughter and processing of livestock or by cross-contamination during food preparation. S. aureus also causes a variety of mild to severe skin and soft tissue infections in humans and other animals. Antibiotic resistance is common in staphylococci. Hospital-associated (HA) S. aureus are resistant to numerous antibiotics, with methicillin-resistant S. aureus (MRSA) presenting significant challenges in health care facilities for over 40 years. During the mid-1990s new human MRSA strains developed outside of hospitals and were termed community-associated (CA). A few years later, MRSA was isolated from horses and methicillin resistance was detected in Staphylococcus intermedius/pseudintermedius from dogs and cats. In 2003, a livestock-associated (LA) MRSA strain was first detected in swine. These methicillin-resistant staphylococci pose additional food safety and occupational health concerns. MRSA has been detected in a small percentage of retail meat and raw milk samples indicating a potential risk for food-borne transmission of MRSA. Persons working with animals or handling meat products may be at increased risk for antibiotic-resistant infections. This review discusses the scope of the problem of methicillin-resistant staphylococci and some strategies for control of these bacteria and prevention of illness.

A population based study of seasonality of skin and soft tissue infections: implications for the spread of CA-MRSA

Methicillin resistant Staphylococcus aureus (MRSA) is currently a major cause of skin and soft tissue infections (SSTI) in the United States. Seasonal variation of MRSA infections in hospital settings has been widely observed. However, systematic time-series analysis of incidence data is desirable to understand the seasonality of community acquired (CA)-MRSA infections at the population level. In this paper, using data on monthly SSTI incidence in children aged 0-19 years and enrolled in Medicaid in Maricopa County, Arizona, from January 2005 to December 2008, we carried out time-series and nonlinear regression analysis to determine the periodicity, trend, and peak timing in SSTI incidence in children at different age: 0-4 years, 5-9 years, 10-14 years, and 15-19 years. We also assessed the temporal correlation between SSTI incidence and meteorological variables including average temperature and humidity. Our analysis revealed a strong annual seasonal pattern of SSTI incidence with peak occurring in early September. This pattern was consistent across age groups. Moreover, SSTIs followed a significantly increasing trend over the 4-year study period with annual incidence increasing from 3.36% to 5.55% in our pediatric population of approximately 290,000. We also found a significant correlation between the temporal variation in SSTI incidence and mean temperature and specific humidity. Our findings could have potential implications on prevention and control efforts against CA-MRSA.

Microbiology of skin and soft tissue infections in the age of community-acquired methicillin-resistant Staphylococcus aureus

The objectives of this study were to determine the etiology of skin and soft-tissue infections (SSTIs) in a general population, and to describe patient characteristics, SSTI types, frequency of microbiologic testing, and the role of methicillin-resistant Staphylococcus aureus (MRSA) over time. Using electronic databases, we identified SSTI episodes and microbiologic testing among members of a large US health plan. Between 2006 and 2009, 648699 SSTI episodes were identified, of which 23% had a specimen, of which 15% were blood. A pathogen was identified in 58% of SSTI cultures. S. aureus was the most common pathogen (80% of positive cultures). Half of S. aureus isolates were MRSA. Among cellulitis and abscess episodes with a positive blood culture, 21% were methicillin-sensitive S. aureus, 16% were MRSA, 21% were beta-hemolytic streptococci and 28% were Gram negative bacteria. Between 1998 and 2009, the percentage of SSTIs for which a culture was obtained increased from 11% to 24%. In SSTI episodes with a culture-confirmed pathogen, MRSA increased from 5% in 1998 to 9% in 2001 to 42% in 2005, decreasing to 37% in 2009. These data can inform the choice of antibiotics for treatment of SSTIs.

Seasonality of staphylococcal infections

Characterization of seasonal variation of Staphylococcus aureus is important in understanding the epidemiology of, and designing preventive strategies against this highly virulent and ever-evolving pathogen. In this review, we summarize the findings of epidemiological studies that have evaluated seasonality in S. aureus colonization and infection. Although most studies published to date are methodologically weak, some seasonal variation in the occurrence of S. aureus infection appears to exist, particularly an association of warm-weather months with S. aureus skin and soft-tissue infections. We highlight the limitations of the published literature, and provide suggestions for future studies on this topic.