APIC Chapter 13 Journal Club April 15, 2015 Collateral benefit of screening patients for methicillin-resistant Staphylococcus aureus at hospital admission: Isolation of patients with multidrug-resistant gram-negative bacteria Presented by: Steven Bock RN CIC NYU Langone Medical Center

The proverbial 30,000 foot snapshot

Collateral benefit of screening patients for MRSA AJIC (43) January 2015 Starting Point All VAMC Hospitals in the United States All patients admitted to VAMC hospitals in 2009 – 2012 were included in the study Included 1.6 million acute care admissions to VAMC hospitals Represented 759,759 unique individual patients All patients admitted were included in the study, all patients screened for MRSA colonization at admission (or if found positive within the prior year, included as if tested at admission All patients MRSA + were put on Contact Precautions (colonized and/or infected) MRSA screening done by nasal swab PCR, typical lab methodology

Collateral benefit of screening patients for MRSA AJIC (43) January 2015 Study Purpose, Definitions Evaluate impact of MRSA colonization on acquisition of multi-drug resistant gram negative rod (MDR-GNB) colonization and/or infection Optimize use of Contact Precautions for MRSA and MDR-GNB colonized and/or infected patients Evaluate benefit of MRSA screening (commonly done) as a proxy for screening for MDR-GNB (not usually done) Project benefits of Contact Precautions on controlling spread of MDR-GNB (as well as MRSA) MRSA defined as MRSA PCR + using standard lab methods New MDR-GNB defined as GNR resistant to at least one drug in 3 different classes of antibiotics, ESBL +, and/or CRE found using standard lab methods, within 30 days of admission

Collateral benefit of screening patients for MRSA AJIC (43) January 2015 Study Design Retrospective review of patient records in national database of all VAMC acute care patients (no control group) All patients MRSA + in previous 12 months and/or found to be MRSA + within first 24 hrs of admission were put on Contact Precautions Mean time between admission and screening results (by PCR) was 12.5 hours New MDR-GNRs were those cases identified within the first 30 days of an admission; could include patients admitted with MDR-GNB and those who acquired MDR-GNB during admission Comparison of patients admitted with MRSA who became MDR-GNB + was made to patients who were MRSA-free at admission but later developed MDR-GNB Study design was IRB-approved

Collateral benefit of screening patients for MRSA AJIC (43) January 2015 Study Findings 1 Of 1.6 million admissions (759,759 unique patients), 14.7% (~111,700 pts) were MRSA + on admission screening and/or MRSA + in previous 12 months; all were put on Contact Precautions for duration of admission & any subsequent readmissions for following 12 months. About 648,000 pts were MRSA negative. 6.3% (~47,800 pts) had history of MDRO + in prior year (e.g., VRE or MDR-GNB – other than MRSA) Total of 17.7% (~134,500 pts) of patients were MRSA/MDRO + at admission or within previous 12 months of admission; all put on Contact Precautions for duration of hospital stay 2.4% of MRSA + patients (~2680 pts) developed new MDR-GNB clinical culture during hospital stay 0.9% of MRSA negative patients (~5830 pts) developed new MDR-GNB clinical culture during hospital stay (difference P<.001)

Collateral benefit of screening patients for MRSA AJIC (43) January 2015 Study Findings 2 Various MDR-GNR were found 0.2% were MDR Acinetobacter 1.9% were MDR Enterobacteriaceae 20% of new MDR-GNB + patients were MRSA + on admission 11% of new MDR-GNB + patients were MDRO + in previous 12 months Net 31% of new MDR-GNB + patients had MRSA or MDRO at admission or in previous 12 months (sensitivity of findings) About 85% of patients who did NOT get MDR-GNB were MRSA negative (specificity of findings) Findings were consistent between VAMC hospitals

Collateral benefit of screening patients for MRSA AJIC (43) January 2015 Study Findings 3 Multilevel regression showed that patients MRSA + at admission had an overall 2.5 fold greater risk of becoming new MDR-GNB during hospital stay vs. MRSA negative pts

Collateral benefit of screening patients for MRSA AJIC (43) January 2015 Study Conclusions & Discussion 1 Being MRSA + increases risk of acquiring new MDR-GNB infection Other studies have shown patients may be co-colonized at admission to acute care hospitals or LTCFs with MRSA & other MDROs (e.g., MDR-GNR). Screening at admission, if done, is usually limited to MRSA Lack of MDR-GNR screening at admission may lead to these patients not getting placed on Contact Precautions Patients put on Contact Precautions for MRSA nasal colonization may help prevent these patients from becoming an undetected reservoir of MDR-GNB

Collateral benefit of screening patients for MRSA AJIC (43) January 2015 Study Conclusions & Discussion 2 MRSA screening with the use of Contact Precautions may help “identify” patients who may have MDR-GNB without any additional screening cost or effort Admission-based MRSA screening with Contact Precautions may help protect a facility from spread of unrelated MDRO Empiric therapy for MRSA + patients may need to be broadened to cover possible MDR-GNR not yet identified Empiric therapy for MRSA – patients may be more narrow than traditionally prescribed; they probably don’t have MDR-GNR (~85%) Cohorting MRSA + patients in the same room should be done cautiously as they may be co-colonized/co-infected with different MDR-GNRs

Collateral benefit of screening patients for MRSA AJIC (43) January 2015 Study Limitations & Strengths 1 Study done in VAMC hospitals, unique patient population MRSA + patients (at admission) may have multiple comorbidities, increasing risk for acquiring MDR-GNB; not controlled in this study MRSA + patients may get cultured more often than MRSA - patients MRSA + patients may have been given additional or more broad-spectrum antibiotics, increasing risk of patient developing MDR-GNR infections * MDR-GNRs identified within 30 days of admission were actually new (not present on admission)

Collateral benefit of screening patients for MRSA AJIC (43) January 2015 Study Limitations & Strengths 2 Positive MDR-GNR cultures were assumed to all be infection and not just colonization; however patients would be put on Contact Precautions for either condition No outcome of acquiring MDR-GNR was made (e.g., longer hospital stay, increased risk of death) Can’t generalize if Contact Precautions policies are different* Extremely large sample size National data set Robust MRSA screening program National uniform EMR database from which to collect data

Collateral benefit of screening patients for MRSA AJIC (43) January 2015 Study Limitations 1 Study done in VAMC hospitals, unique patient population MRSA + patients (at admission) may have multiple comorbidities, increasing risk for acquiring MDR-GNB; not controlled in this study MRSA + patients may get cultured more often than MRSA - patients MRSA + patients may have been given additional or more broad-spectrum antibiotics, increasing risk of patient developing MDR-GNR infections * MDR-GNRs identified within 30 days of admission were actually new (not present on admission)

Appraisal Results Level III – Non-Experimental Study Score: B Thank you! APIC Greater NY Meeting Here