Acute Bacterial skin and skin structure infections (ABSSSIs) are an increasingly common reason for hospital admissions.1,2 In recent years, hospitals have experienced a 71% increase in the rate of hospitalizations due to SSTIs.2 Skin and soft tissue infections are associated with significant health care costs.1,3,4 In a matched cohort study, Hatoum et al3 reported that patients ABSSSIs incurred on average 3.81 additional days and $14,794 excess hospitalization charges. In addition, Jenkins et al5 evaluated adult patients hospitalized with ABSSSIs had frequent use of potentially unnecessary diagnostic studies, broad-spectrum antibiotic therapy, and prolonged treatment courses. Although acute bacterial SSTIs are among the most common infections requiring hospitalizations, there is currently a of lack data regarding their use of resources and outcomes.
In this issue, Berger et al6 describes patterns of antibiotics use for ABSSSIs in a large patient population. The authors used a sample of 22,382 adult patients hospitalized with a principal diagnosis of skin and skin structure infection between January 1, 2000 and June 30, 2009. The authors examined temporal changes in initial antibiotic therapy, frequency of initial regimen containing activity against methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa, and use of regimens with broad coverage (ie, activity against gram-positive, gram-negative, and anaerobic pathogens). The analysis was examined for each year in the study, on an overall basis, and for patients in each of 3 infection subgroups: acute infections, chronic/ulcerative infections, and surgical-site infections.
The sample size contained an uneven distribution of patients by region with 79% of the patients coming from either the Northeast or Midwest region. Over the study period, the authors demonstrated significant changes in prescribing habits for initial antibiotic therapy for patients with ABSSSIs. The use of cefazolin and ampicillin/sulbactam significantly decreased from 31.8% and 26.1%, respectively, in 2000 to 11.1% and 10.4%, respectively, in 2009 (both P < 0.01). The use of clindamycin remained relatively the same, 11.3% in 2000 to 13.6% in 2009; whereas the use of piperacillin/tazobactam and vancomycin significantly increased over the study period. In 2000, piperacillin/tazobactam was used 6.8% of the time, and this increased to 22.9% in 2009 (P < 0.01). Vancomycin had a greater increase in use from 20.1% in 2000 to 58.2% in 2009 (P < 0.01). Initial antibiotic therapy with coverage toward either MRSA or Pseudomonas dramatically increased. Antibiotic therapy with MRSA activity increased from 30% in 2000 to 71% in 2009 (P < 0.01), whereas antibiotic therapy with an antipseudomonal agent increased from 16% in 2000 to 28% in 2009 (P < 0.01).
One potential reason for the increase in SSTIs as well as the changes in the prescribing habits of initial antibiotic therapy is the emergence of antimicrobial resistance. S aureus and Streptococcus pyogenes are common causes of a variety of skin and skin structure infections. In the past 2 decades, community-acquired MRSA has emerged as a significant cause of skin and skin structure infections. Several recent studies from either single centers or populations have reported community-acquired MRSA as the leading cause of SSTIs and at unprecedented levels in many regions.1,7,8 The 2005 Infectious Disease Society of America guidelines for the diagnosis and management of SSTIs recommends in cases of S aureus to assume the organism is resistant because of the prevalence of MRSA.9 Considering these reports, it is not surprising to see the changes in the prescribing habits of initial antibiotic therapy with an MRSA agent.
The changes in patterns of antibiotic prescribed for patients with ABSSSIs provided by Berger et al does raise a question regarding the appropriateness of antibiotic therapy. Jenkins et al5 reported unnecessary use of broad-spectrum antibiotic therapy. In their single-center experience of patients hospitalized with SSTIs, 97% of the patients with a positive culture result had either S aureus or streptococci isolated.5 Despite the predominance of gram-positive pathogens, nearly three fourths of the patients received antibiotic therapy with activity against anaerobes, and two thirds of the patients received antibiotic therapy with activity against gram-negative pathogens.5 These findings compiled with the changes in prescribing of initial antibiotic therapy could be suggestive that patients with ABSSSIs are important targets for antimicrobial stewardship programs (ASPs).
Antimicrobial Stewardship has the ability to affect outcomes and costs associated with treating the disease through initiatives to optimize antibiotic use. Summa Health System (SHS), a large community-based teaching hospital, initiated a full comprehensive Antimicrobial Stewardship Program (ASP) in 2010 at Summa Akron City Hospital. The ASP is led by a clinical pharmacist (1 full time position) and an infectious disease physician (0.5 half time position). The core ASP strategy used is prospective audit with feedback. In 2012, SHS began an initiative to improve the outcomes and costs associated with adult patients admitted with acute bacterial skin and skin structure infections (ABSSSI) through their ASP.10 The ASP focused on improving patient care and outcomes in patients admitted with ABSSSIs. In a 6-month period, the ASP intervened on 62 patients with ABSSSIs. A total of 85 recommendations were made on the 62 patients with an acceptance rate of 95%. The common interventions made by the ASP included the following: (1) antibiotic regimen changes such as anti-MRSA agent to a β-lactam for methicillin-sensitive S aureus infections, (2) de-escalation from an antipseudomonal β-lactam plus anti-MRSA agent to monotherapy with a nonantipseudomonal β-lactam, (3) dosage changes, (4) antimicrobial duration, and (5) infectious disease consultation. Through prospective evaluation by the ASP, improved patient outcomes were seen by a reduction in length of stay from a mean of 6.2 days for the historical control group to 4.4 days for the intervention group (P < 0.001) and a reduction in the 30-day ABSSSI readmission rate from 6.2% for historical control to 3% for the intervention group (P = NS).
The evolving epidemiology and empiric treatment of ABSSSIs present an opportunity for antimicrobial stewardship. A prospective audit and feedback approach has the potential to improve patient outcomes. Berger et al present data that demonstrate empiric treatment of ABSSSIs has evolved over the past decade as a result of changes in epidemiology and recommendations. Jenkins et al and our experience at SHS demonstrate that patients may receive unnecessary broad-spectrum antibiotics and antimicrobial stewardship may have a significant impact on the resources used for patients with ABSSSIs. We agree that further research is needed in the area of ABSSSIs to evaluate epidemiology, use of resources, and outcomes.
1. Zervos MJ, Freeman K, Vo L, et al. Epidemiology and outcomes of complicated skin and soft-tissue infections in hospitalized patients. J Clin Microbiol
. 2012; 50 (2): 238–245.
2. Hersh AL, Chambers HF, Maselli JH, et al. National trends in ambulatory visits and antibiotic prescribing for skin and soft-tissue infections. Arch Intern Med
. 2008; 168 (14): 1585–1591.
3. Hatoum HT, Akhras KS, Lin SJ. The attributable clinical and economic burden of skin and skin structure infections in hospitalized patients: a matched cohort study. Diagn Microbiol Infect Dis
. 2009; 64: 305–310.
4. Lipsky BA, Weigelt JA, Gupta V, et al. Skin, soft-tissue, bone, and joint infections in hospitalized patients: epidemiology and microbiological, clinical, and economic outcomes. Infect Control Hosp Epidemiol
. 2007; 28: 1290–1298.
5. Jenkins TC, Sabel AL, Sarcone EE, et al. Skin and soft-tissue infections requiring hospitalization at an academic medical center opportunities for antimicrobial stewardship. Clin Infect Dis
. 2010; 51 (8): 895–903.
6. Berger A, Edelsberg J, Oster G, et al. Patterns of initial antibiotic therapy for complicated skin and skin structure infections (cSSSI) in US Hospitals, 2000–2009. Infect Dis Clin Pract
. 2013; 159–167.
7. Dukic VM, Lauderdale DS, Wilder J, et al. Epidemics of community-associated methicillin-resistant Staphylococcus aureus
in the United States: a meta-analysis. PLoS One
. 2013; 8 (1): e52722.
8. Lipsky BA, Moran GJ, Napolitano LM, et al. A prospective, multicenter, observation study of complicated skin and soft tissue infections in hospitalized patients: clinical characteristics, medical treatment, and outcomes. BMC Infect Dis
. 2012; 12: 227.
9. Stevens DL, Bisno AL, Chambers HF, et al. Practice guidelines for the diagnosis and management of skin and soft-tissue infections. Clin Infect Dis
. 2005; 41: 1373–1406.
10. Pasquale TR, Trienski TL, Olexia DE, Myers JP, Tan MJ, Leung AK, Poblete JE, File TM Jr. “Evaluation of the Impact of an Antimicrobial Stewardship Program in Patients with Acute Bacterial Skin and Skin Structure Infections (ABSSSI) at a Teaching Hospital”. Poster Presentation at the Infectious Disease Society of America Annual Meeting, San Diego, CA. October 17–21, 2012. Poster number 744.