Clinical utility of negative methicillin-resistant Staphylococcus aureus (MRSA) nasal surveillance swabs in skin and skin structure infections

The Impact of a Methicillin-Resistant Staphylococcus Aureus Nasal Polymerase Chain Reaction Protocol on Vancomycin Length of Therapy Among Patients With Skin and Soft Tissue Infections

Objective: We evaluated the impact of a methicillin-resistant Staphylococcus aureus (MRSA) nasal polymerase chain reaction (PCR) protocol on the vancomycin length of therapy (LOT) for skin and soft tissue infections (SSTIs). Design: Retrospective quasi-experimental pre- and post- MRSA nasal PCR protocol implementation study. Setting: Tertiary-care academic medical center in Jacksonville, Florida. Patients: Eligible patients received empiric vancomycin for SSTIs from January 1st to September 30th 2020 (pre-implementation group) and from January 1st to September 30th 2022 (post-implementation group). Intervention: The electronic health system software was modified to provide a best-practice advisory (BPA) prompt to the pharmacist upon order verification of vancomycin for patients with SSTIs. Methods: We reviewed patient records to determine the time from vancomycin prescription to de-escalation. The secondary outcomes were incidence of acute kidney injury (AKI), number of vancomycin levels collected, and hospital length of stay (LOS). Results: The study included 131 patients (pre-implementation, n = 86 and post-implementation, n = 45). There was no significant difference in vancomycin length of therapy (LOT) between implementation groups: mean LOT in days and standard deviation (SD) were 2.7 (1.9) and 2.6 (1.3), respectively, p-value 0.493. Of significance, in the post-implementation group, vancomycin LOT between patients with a negative and positive MRSA PCR were 2.3 (1.1) and 3.9 (1.6), p-value 0.006. There was no difference in secondary outcomes. Conclusion: The utilization of the MRSA nasal PCR to guide vancomycin de-escalation did not significantly change the vancomycin LOT, however in the post-implementation group there was a significant difference in vancomycin LOT between negative and positive MRSA PCRs.

Swab Testing to Optimize Pneumonia treatment with empiric Vancomycin (STOP-Vanc): study protocol for a randomized controlled trial

BACKGROUND

Vancomycin, an antibiotic with activity against methicillin-resistant Staphylococcus aureus (MRSA), is frequently included in empiric treatment for community-acquired pneumonia (CAP) despite the fact that MRSA is rarely implicated in CAP. Conducting polymerase chain reaction (PCR) testing on nasal swabs to identify the presence of MRSA colonization has been proposed as an antimicrobial stewardship intervention to reduce the use of vancomycin. Observational studies have shown reductions in vancomycin use after implementation of MRSA colonization testing, and this approach has been adopted by CAP guidelines. However, the ability of this intervention to safely reduce vancomycin use has yet to be tested in a randomized controlled trial.

METHODS

STOP-Vanc is a pragmatic, prospective, single center, non-blinded randomized trial. The objective of this study is to test whether the use of MRSA PCR testing can safely reduce inappropriate vancomycin use in an intensive care setting. Adult patients with suspicion for CAP who are receiving vancomycin and admitted to the Medical Intensive Care Unit at Vanderbilt University Medical Center will be screened for eligibility. Eligible patients will be enrolled and randomized in a 1:1 ratio to either receive MRSA nasal swab PCR testing in addition to usual care (intervention group), or usual care alone (control group). PCR testing results will be transmitted through the electronic health record to the treating clinicians. Primary providers of intervention group patients with negative swab results will also receive a page providing clinical guidance recommending discontinuation of vancomycin. The primary outcome will be vancomycin-free hours alive, defined as the expected number of hours alive and free of the use of vancomycin within the first 7 days following trial enrollment estimated using a proportional odds ratio model. Secondary outcomes include 30-day all-cause mortality and time alive off vancomycin.

DISCUSSION

STOP-Vanc will provide the first randomized controlled trial data regarding the use of MRSA nasal swab PCR testing to guide antibiotic de-escalation. This study will provide important information regarding the effect of MRSA PCR testing and antimicrobial stewardship guidance on clinical outcomes in an intensive care unit setting.

TRIAL REGISTRATION

ClinicalTrials.gov NCT06272994. Registered on February 22, 2024.

Impact of Methicillin-Resistant Staphylococcus aureus Nasal Polymerase Chain Reaction Screening Tests on Duration of Vancomycin Therapy for Skin and Soft Tissue Infections

Background: Recent literature demonstrated a 24-hour reduction in vancomycin duration of therapy (DOT) for skin and soft tissue infections (SSTIs) with a negative methicillin-resistant staphylococcus aureus (MRSA) nasal screening versus a positive nasal screening. Objective of this study was to investigate vancomycin DOT in patients with SSTIs who received MRSA nasal polymerase chain reaction (PCR) screening versus those who did not receive MRSA nasal PCR screening. Methods: A retrospective, multi-center, cohort study was completed in admitted adult patients on vancomycin for SSTI from 01/01/2020 to 09/30/2022. Hospital policy permits any clinician to order a MRSA nasal PCR screening test for various indications, including SSTIs, pneumonia and sepsis. Results: One-hundred-fifty-one patients were included, of which 71 had MRSA nasal PCR screening tests obtained, and 80 did not. The median vancomycin DOT in patients with MRSA nasal PCR screening tests was 19.9 versus 36.7 hours (P = .014) in patients without screening tests. Conclusion: Patients with SSTIs who receive MRSA nasal PCR screening tests have a shortened vancomycin DOT. These results contribute to current data in support of the efficacy and clinical utility of obtaining MRSA nasal PCR screening tests for SSTIs.

Review: sepsis guidelines and core measure bundles

Sepsis is a major cause of mortality worldwide and is the third-leading cause of death in the United States. Sepsis is resource-intensive and requires prompt recognition and treatment to reduce mortality. The impact of sepsis is not only on in-hospital survival but extends into post-discharge quality of life and risk of re-admission. As the understanding of sepsis physiology evolved, so have the recommended screening tools and treatment protocol which challenge prior standards of care. There have been noteworthy efforts by the Surviving Sepsis Campaign, the Third International Consensus Definitions for Sepsis and the Centers for Medicare and Medicaid Services to establish core measure bundles. This review highlights both the 2021 SSC International Guidelines and the 2015 CMS Severe Sepsis/Septic Shock Core Measure Bundle, or SEP-1. Notably, the SEP-1 bundle was implemented as a value-based purchasing program, linking care of sepsis patients to financial incentives. The objective is to explore the most current evidence-based data to inform clinical practice while utilizing the available guidelines as a roadmap.

Approaches to Reduce Use and Duration of Anti-MRSA Agents for Antimicrobial Stewardship Programs: A Review of Recent Literature

Antimicrobial stewardship programs (ASPs) have the potential to effectively deescalate unnecessary methicillin-resistant Staphylococcus aureus (MRSA) coverage. This review summarizes literature published from 2014 through 2021 describing contemporary ASP methods and their resulting effectiveness at reducing anti-MRSA agent use (ie vancomycin, linezolid, daptomycin, ceftaroline, and clindamycin). This review of the literature examined the following strategies, which had reports of success in either decreasing the use or duration of anti-MRSA agents: prospective review and feedback, antibiotic timeouts, health system or department protocol changes, polymerase chain reaction (PCR) and rapid testing of patient samples. Most of the current literature continue to support most ASP interventions including antibiotic timeouts, pathways, and molecular testing including MRSA nasal PCRs and rapid diagnostic testing can be successful at reducing unnecessary anti-MRSA use.

Prevention and treatment of recurrent cellulitis

PURPOSE OF REVIEW

Recurrent cellulitis is a challenging clinical condition affecting up to 47% of patients after the first episode, especially those with predisposing risk factors. The purpose of this review is to describe the state of the art of literature evidence and to highlight recent developments in its management.

RECENT FINDINGS

Recurrent cellulitis can occur after successful treatment of cellulitis. Conditions that commonly increase the risk of cellulitis include local and systemic modifiable and nonmodifiable factors. A rigorous approach to the management of risk factors and treatment of acute infection is important as the risk of recurrence rises with repeated episodes. Risk factors, if present, need to be targeted in association with antibiotic prophylaxis. Penicillin V is the preferred antibiotic for prevention but other antibiotics and new drugs can be considered in cases of β-lactam allergy, intolerance, or failure.

SUMMARY

Recurrent cellulitis is associated with short term and long-term morbidity as well as significant healthcare costs. Management of underlying predisposing conditions is crucial to prevent recurrence in addition with evaluation of pharmacological measures, but specialized and multidisciplinary skills are needed. More efforts are needed to prevent and treat this underestimated problem.

Does a Positive Methicillin-Resistant Staphylococcus aureus (MRSA) Nasal Screen Predict the Risk for MRSA Skin and Soft Tissue Infection?

Background:

Skin and soft tissue infections (SSTIs) are often caused by gram-positive bacteria that colonize the skin. Given the overuse of antibiotics, SSTIs are increasingly caused by resistant bacteria, including methicillin-resistant Staphylococcus aureus (MRSA). Guidance on the utility of MRSA nasal screening for MRSA SSTI is limited.

Objective:

To determine whether MRSA nasal screening predicts the risk of MRSA SSTIs.

Methods:

This was a single-center, retrospective cohort study of adult patients with an SSTI diagnosis that had MRSA nasal screening and wound cultures obtained within 48 hours of starting antibiotics. Sensitivity, specificity, positive and negative predictive value, and positive and negative likelihood ratios were calculated using VassarStats. Pretest and posttest probabilities were estimated with Microsoft Excel.

Results:

A total of 884 patient encounters were reviewed between December 1, 2018, and October 31, 2021, and 300 patient encounters were included. The prevalence of MRSA SSTI was 18.3%. The MRSA nasal colonization had a sensitivity of 63.6%, specificity of 93.9%, positive predictive value of 70.0% (95% CI = 55.2%-81.7%), negative predictive value of 92.0% (95% CI = 87.7%-94.9%), positive likelihood ratio of 10.39 (95% CI = 6.12-17.65), negative likelihood ratio of 0.39 (95% CI = 0.27-0.55), positive posttest probability of 70.0%, and negative posttest probability of 8.0%.

Conclusions:

Given the high positive likelihood ratio, a positive MRSA nasal screen was associated with a large increase in the probability of MRSA SSTI at our institution, and a negative MRSA nasal screen was associated with a small but potentially significant decrease in the probability of MRSA SSTI.