Determining the Utility of Methicillin-Resistant Staphylococcus aureus Nares Screening in Antimicrobial Stewardship.

BACKGROUND: Treatment of suspected methicillin-resistant Staphylococcus aureus (MRSA) is a cornerstone of many antibiotic regimens; however, there is associated toxicity. The Department of Veterans Affairs (VA) hospitals screen each patient for MRSA nares colonization on admission and transfer. The objective was to determine the negative predictive value (NPV) of MRSA screening in the determination of subsequent positive clinical culture for MRSA. High NPVs with MRSA nares screening may be used as a stewardship tool. METHODS: This was a retrospective cohort study across VA medical centers nationwide from 1 January 2007 to 1 January 2018. Data from patients with MRSA nares screening were obtained from the VA Corporate Data Warehouse. Subsequent clinical cultures within 7 days of the nares swab were evaluated for the presence of MRSA. Sensitivity, specificity, positive predictive values, and NPVs were calculated for the entire cohort as well as subgroups for specific culture sites. RESULTS: This cohort yielded 561 325 clinical cultures from a variety of anatomical sites. The sensitivity and specificity for positive MRSA clinical culture were 67.4% and 81.2%, respectively. The NPV of MRSA nares screening for ruling out MRSA infection was 96.5%. The NPV for bloodstream infections was 96.5%, for intraabdominal cultures it was 98.6%, for respiratory cultures it was 96.1%, for wound cultures it was 93.1%, and for cultures from the urinary system it was 99.2%. CONCLUSION: Given the high NPVs, MRSA nares screening may be a powerful stewardship tool for deescalation and avoidance of empirical anti-MRSA therapy.

Temporal trends of inpatient C. difficile infections within the Veterans Health Administration hospitals: An analysis of the effect of molecular testing, time to testing, and mandatory reporting.

BACKGROUND: Clostridium difficile infection (CDI) is a reportable hospital metric associated with significant healthcare expenditures. The epidemiology of CDI is pivotal to the implementation of preventative measures. OBJECTIVE: To portray temporal CDI trends in Veterans Health Administration (VA) hospitals. DESIGN: A retrospective analysis of veterans who had stool testing for C. difficile. SETTING: VA acute-care hospitals within the continental United States. METHODS: Data were mined from the VA's Corporate Data Warehouse. CDI is reported per 10,000 patient days. RESULTS: From 2006 to 2016, 472,346 patients had C. difficile testing. Overall, decreases in incidence of total CDI (16.81 to 13.66) and hospital-onset healthcare facility-associated (HO-HCFA) CDI (10.87 to 6.41) were observed. Temporal increases in the incidence of total and HO-HCFA CDI were associated with the increased use of molecular testing (P < .0001). Decreased use of fluoroquinolones (P < .0001), clindamycin (P = .0006), and third-generation cephalosporins (P = .0002) correlated with decreased rates of CDI, but VA mandatory reporting did not influence CDI rates (P = .24). The overall crude 30-day mortality of patients with CDI decreased from 2.17 deaths per 10,000 patient days in 2006 to 1.41 in 2016. The frequency of International Classification of Disease, Ninth/Tenth Revision (ICD-9/10) discharge diagnosis for CDI was 73.3%. CONCLUSION: Molecular testing was associated with increased incidence of CDI. Controlling CDI is likely multifactorial. Although the VA initiative to report cases of hospital-acquired CDI was not significant in our model, the advent of stewardship programs throughout the VA and reductions in the use of third-generation cephalosporins, fluoroquinolones, and clindamycin were significantly associated with reduced rates of CDI.

Successful cure of daptomycin-non-susceptible, vancomycin-intermediate Staphylococcus aureus prosthetic aortic valve endocarditis directed by synergistic in vitro time-kill study.

Infectious complications following surgical valve replacements are extremely difficult to treat, often requiring prolonged antimicrobials therapy with or without surgery. Vancomycin-intermediate Staphylococcus aureus is an infrequent pathogen, with an estimated prevalence of less than 0.3%, but presents even greater challenges. We report a case of successful cure of daptomycin-non-susceptible and vancomycin-intermediate Staphylococcus aureus prosthetic valve endocarditis using an eight-week course of combination antimicrobial therapy. Using time-kill study, the combination of daptomycin plus ceftaroline and rifampin resulted in a greater than 4 log reduction of bacterial growth at 24 hours. This antimicrobial combination was used for a total of eight weeks with a successful outcome.