Timothy C. Jenkins

Implementing an Antibiotic Stewardship Program: Guidelines by the Infectious Diseases Society of America and the Society for Healthcare Epidemiology of America

Evidence-based guidelines for implementation and measurement of antibiotic stewardship interventions in inpatient populations including long-term care were prepared by a multidisciplinary expert panel of the Infectious Diseases Society of America and the Society for Healthcare Epidemiology of America. The panel included clinicians and investigators representing internal medicine, emergency medicine, microbiology, critical care, surgery, epidemiology, pharmacy, and adult and pediatric infectious diseases specialties. These recommendations address the best approaches for antibiotic stewardship programs to influence the optimal use of antibiotics.

Impact of Routine Infectious Diseases Service Consultation on the Evaluation, Management, and Outcomes of Staphylococcus aureus Bacteremia

To the Editor—Jenkins et al. [1] analyzed the role of routine infectious diseases consultation on Staphylococcus aureus bacteremia. The study did not show, however, a statistical difference in terms of treatment failure (such as bacteremia recurrence or death) between the group of patients who received routine infectious diseases consultation and the group of patients who did not receive it. With a clinically and statistically significant difference in median duration of therapy between 2 groups (29 vs. 16 days), it may be possible to argue that the infectious diseases consultation may be simply increasing the duration of therapy but not improving the outcome of patients. We do not consider that this is the case, however. The investigators reviewed cases for up to 12 weeks by protocol and actually followed-up patients for a median of ∼60 days for both groups. However, late recurrence of S. aureus infection is common, and it may have been missed in the study. A different study showed a recurrence rate of 12.3% for S. aureus bacteremia [2]. Another study reviewed 10 cases of genetically confirmed, recurrent S. aureus bacteremia, and 5 of these cases involved recurrence after an interval 160 days (range, 68 days–9 months) [3]. We think that it is too early to conclude that infectious diseases consultation does not have an impact on the clinical outcome of S. aureus bacteremia. An evaluation for a longer period of time will provide more insight into this issue.

Skin and Soft-Tissue Infections Requiring Hospitalization at an Academic Medical Center: Opportunities for Antimicrobial Stewardship

BACKGROUND Although complicated skin and soft-tissue infections (SSTIs) are among the most common infections requiring hospitalization, their clinical spectrum, management, and outcomes have not been well described. METHODS We report a cohort of consecutive adult patients hospitalized for SSTI from 1 January through 31 December 2007 at an academic medical center. Cases meeting inclusion criteria were reviewed and classified as cellulitis, cutaneous abscess, or SSTI with additional complicating factors. RESULTS In total, 322 patients were included; 66 (20%) had cellulitis, 103 (32%) had cutaneous abscess, and 153 (48%) had SSTI with additional complicating factors. Injection drug use, diabetes mellitus, and alcohol abuse were common comorbidities. Serum inflammatory markers were routinely measured and blood cultures and imaging studies were routinely performed in each group. Of 150 patients with a positive culture result for an abscess, deep tissue, or blood, Staphylococcus aureus or streptococci were identified in 145 (97%). Use of antibiotics with broad aerobic gram-negative activity (61%-80% of patients) or anaerobic activity (73%-83% of patients) was frequent in each group. The median duration of therapy for cellulitis, cutaneous abscess, and SSTI with additional complicating factors was 13 (interquartile range [IQR], 10-14), 13 (IQR, 10-16), and 14 (IQR, 11-17) days, respectively. Treatment failure, recurrence, or rehospitalization due to SSTI within 30 days occurred in 12.1%, 4.9%, and 9.2% of patients, respectively. CONCLUSIONS Hospitalizations for SSTI were common; more than half were due to cellulitis or cutaneous abscess. Frequent use of potentially unnecessary diagnostic studies, broad-spectrum antibiotic therapy, and prolonged treatment courses in these patients suggest targets for antimicrobial stewardship programs.

Executive Summary: Implementing an Antibiotic Stewardship Program: Guidelines by the Infectious Diseases Society of America and the Society for Healthcare Epidemiology of America

Evidence-based guidelines for implementation and measurement of antibiotic stewardship interventions in inpatient populations including long-term care were prepared by a multidisciplinary expert panel of the Infectious Diseases Society of America and the Society for Healthcare Epidemiology of America. The panel included clinicians and investigators representing internal medicine, emergency medicine, microbiology, critical care, surgery, epidemiology, pharmacy, and adult and pediatric infectious diseases specialties. These recommendations address the best approaches for antibiotic stewardship programs to influence the optimal use of antibiotics.

Risk-based human immunodeficiency virus (HIV) testing fails to detect the majority of HIV-infected persons in medical care Settings.

Objectives: To evaluate opportunities for earlier human immunodeficiency virus (HIV) diagnosis within a comprehensive public health care system. Study Design: Retrospective review of newly diagnosed HIV-infected patients between September 2001 and December 2003. Results: One hundred twenty of 348 (34%) newly diagnosed HIV-infected patients had medical care within our system in the 3 years before diagnosis. One hundred five of 120 (88%) patients had at least 1 prior encounter in the emergency department or urgent care center, whereas just 12 (10%) HIV diagnoses were made in these 2 sites. Only 33 (28%) patients previously presented with an HIV clinical indicator condition or sexually transmitted infection. Conclusions: Although one-third of newly diagnosed HIV-infected patients had clinical visits in the 3 years before diagnosis, few presented with clinical conditions typically associated with HIV infection. Targeted testing based on clinical presentations is not likely to result in substantially earlier HIV diagnosis. Routine screening in high prevalence settings could be more effective.

Epidemiology of Healthcare‐Associated Bloodstream Infection Caused by USA300 Strains of Methicillin‐Resistant Staphylococcus aureus in 3 Affiliated Hospitals

OBJECTIVE To describe the epidemiology of bloodstream infection caused by USA300 strains of methicillin-resistant Staphylococcus aureus (MRSA), which are traditionally associated with cases of community-acquired infection, in the healthcare setting. DESIGN Retrospective cohort study. SETTING Three academically affiliated hospitals in Denver, Colorado. METHODS Review of cases of S. aureus bloodstream infection during the period from 2003 through 2007. Polymerase chain reaction was used to identify MRSA USA300 isolates. RESULTS A total of 330 cases of MRSA bloodstream infection occurred during the study period, of which 286 (87%) were healthcare-associated. The rates of methicillin resistance among the S. aureus isolates recovered did not vary during the study period and were similar among the 3 hospitals. However, the percentages of cases of healthcare-associated MRSA bloodstream infection due to USA300 strains varied substantially among the 3 hospitals: 62%, 19%, and 36% (P<.001) for community-onset cases and 33%, 3%, and 33% (P=.005) for hospital-onset cases, in hospitals A, B, and C, respectively. In addition, the number of cases of healthcare-associated MRSA bloodstream infection caused by USA300 strains increased during the study period at 2 of the 3 hospitals. At each hospital, USA300 strains were most common among cases of community-associated infection and were least common among cases of hospital-onset infection. Admission to hospital A (a safety-net hospital), injection drug use, and human immunodeficiency virus infection were independent risk factors for healthcare-associated MRSA bloodstream infection due to USA300 strains. CONCLUSIONS The prevalence of USA300 strains among cases of healthcare-associated MRSA bloodstream infection varied dramatically among geographically clustered hospitals. USA300 strains are replacing traditional healthcare-related strains of MRSA in some healthcare settings. Our data suggest that the prevalence of USA300 strains in the community is the dominant factor affecting the prevalence of this strain type in the healthcare setting.

Antibiotic prescribing practices in a multicenter cohort of patients hospitalized for acute bacterial skin and skin structure infection.

OBJECTIVE Hospitalizations for acute bacterial skin and skin structure infection (ABSSSI) are common. Optimizing antibiotic use for ABSSSIs requires an understanding of current management. The objective of this study was to evaluate antibiotic prescribing practices and factors affecting prescribing in a diverse group of hospitals. DESIGN Multicenter, retrospective cohort study. SETTING Seven community and academic hospitals. METHODS Children and adults hospitalized between June 2010 and May 2012 for cellulitis, wound infection, or cutaneous abscess were eligible. The primary endpoint was a composite of 2 prescribing practices representing potentially avoidable antibiotic exposure: (1) use of antibiotics with a broad spectrum of activity against gram-negative bacteria or (2) treatment duration greater than 10 days. RESULTS A total of 533 cases were included: 320 with nonpurulent cellulitis, 44 with wound infection or purulent cellulitis, and 169 with abscess. Of 492 cases with complete prescribing data, the primary endpoint occurred in 394 (80%) cases and varied significantly across hospitals (64%-97%; P < .001). By logistic regression, independent predictors of the primary endpoint included wound infection or purulent cellulitis (odds ratio [OR], 5.12 [95% confidence interval (CI)], 1.46-17.88), head or neck involvement (OR, 2.83 [95% CI, 1.17-6.82]), adult cases (OR, 2.20 [95% CI, 1.18-4.11]), and admission to a community hospital (OR, 1.90 [95% CI, 1.05-3.44]). CONCLUSIONS Among patients hospitalized for ABSSSI, use of antibiotics with broad gram-negative activity or treatment courses longer than 10 days were common. There may be substantial opportunity to reduce antibiotic exposure through shorter courses of therapy targeting gram-positive bacteria.

Avoidable antibiotic exposure for uncomplicated skin and soft tissue infections in the ambulatory care setting.

BACKGROUND Uncomplicated skin and soft tissue infections are among the most frequent indications for outpatient antibiotics. A detailed understanding of current prescribing practices is necessary to optimize antibiotic use for these conditions. METHODS This was a retrospective cohort study of children and adults treated in the ambulatory care setting for uncomplicated cellulitis, wound infection, or cutaneous abscess between March 1, 2010 and February 28, 2011. We assessed the frequency of avoidable antibiotic exposure, defined as the use of antibiotics with broad gram-negative activity, combination antibiotic therapy, or treatment for 10 or more days. Total antibiotic-days prescribed for the cohort were compared with antibiotic-days in 4 hypothetical short-course (5-7 days), single-antibiotic treatment models consistent with national guidelines. RESULTS A total of 364 cases were included for analysis (155 cellulitis, 41 wound infection, and 168 abscess). Antibiotics active against methicillin-resistant Staphylococcus aureus were prescribed in 61% of cases of cellulitis. Of 139 cases of abscess where drainage was performed, antibiotics were prescribed in 80% for a median of 10 (interquartile range, 7-10) days. Of 292 total cases where complete prescribing data were available, avoidable antibiotic exposure occurred in 46%. This included use of antibiotics with broad gram-negative activity in 4%, combination therapy in 12%, and treatment for 10 or more days in 42%. Use of the short-course, single-antibiotic treatment strategies would have reduced prescribed antibiotic-days by 19% to 55%. CONCLUSIONS Approximately half of uncomplicated skin infections involved avoidable antibiotic exposure. Antibiotic use could be reduced through treatment approaches using short courses of a single antibiotic.

Effects of Clinical Pathways for Common Outpatient Infections on Antibiotic Prescribing

BACKGROUND Antibiotic overuse in the primary care setting is common. Our objective was to evaluate the effect of a clinical pathway-based intervention on antibiotic use. METHODS Eight primary care clinics were randomized to receive clinical pathways for upper respiratory infection, acute bronchitis, acute rhinosinusitis, pharyngitis, acute otitis media, urinary tract infection, skin infections, and pneumonia and patient education materials (study group) versus no intervention (control group). Generalized linear mixed effects models were used to assess trends in antibiotic prescriptions for non-pneumonia acute respiratory infections and broad-spectrum antibiotic use for all 8 conditions during a 2-year baseline and 1-year intervention period. RESULTS In the study group, antibiotic prescriptions for non-pneumonia acute respiratory infections decreased from 42.7% of cases at baseline to 37.9% during the intervention period (11.2% relative reduction) (P<.0001) and from 39.8% to 38.7%, respectively, in the control group (2.8% relative reduction) (P=.25). Overall use of broad-spectrum antibiotics in the study group decreased from 26.4% to 22.6% of cases, respectively (14.4% relative reduction) (P<.0001) and from 20.0% to 19.4%, respectively, in the control group (3.0% relative reduction) (P=.35). There were significant differences in the trends of prescriptions for acute respiratory infections (P<.0001) and broad-spectrum antibiotic use (P=.001) between the study and control groups during the intervention period, with greater declines in the study group. CONCLUSIONS This intervention was associated with declining antibiotic prescriptions for non-pneumonia acute respiratory infections and use of broad-spectrum antibiotics over the first year. Evaluation of the impact over a longer study period is warranted.

Risk factors for drug-resistant Streptococcus pneumoniae and antibiotic prescribing practices in outpatient community-acquired pneumonia.

OBJECTIVES Due to antimicrobial resistance in Streptococcus pneumoniae, national guidelines recommend a respiratory fluoroquinolone or combination antimicrobial therapy for outpatient treatment of community-acquired pneumonia (CAP) associated with risk factors for drug-resistant S. pneumoniae (DRSP). The objectives of this study were to assess the prevalence of these risk factors and antibiotic prescribing practices in cases of outpatient CAP treated in the acute care setting. METHODS This was a retrospective cohort study of adult outpatients treated for CAP in the emergency department (ED) or urgent care center of an urban, academic medical center from May 1, 2009, through October 31, 2009, and comparison of antibiotic therapy in cases with and without DRSP risk factors. RESULTS Of 175 patients, 90 (51%) had at least one DRSP risk factor, most commonly asthma (n = 28, 16%), alcohol abuse (n = 24, 14%), diabetes mellitus (n = 18, 10%), chronic obstructive pulmonary disease (n = 16, 9%), age > 65 years (n = 16, 9%), and use of antibiotics within 3 months (15, 9%). Antibiotic prescriptions were similar among cases with and without DRSP risk factors: a macrolide (62% vs. 59%, respectively, p = 0.65), doxycycline (27% vs. 28%, p = 0.82), or a respiratory fluoroquinolone (9% vs. 9%, p = 0.90). Concordance with national guideline treatment recommendations was significantly lower in cases with DRSP risk factors (9% vs. 87%, p < 0.0001). CONCLUSIONS DRSP risk factors were present in approximately half of outpatient CAP cases treated in the acute care setting; however, guideline-concordant antibiotic therapy was infrequent. Strict adherence to current guidelines would substantially increase use of fluoroquinolones or combination therapy. Whether the potential risks associated with these broad-spectrum regimens are justified by improved clinical outcomes requires further study.