Clare Rock

Carbapenem Therapy Is Associated With Improved Survival Compared With Piperacillin-Tazobactam for Patients With Extended-Spectrum β-Lactamase Bacteremia

BACKGROUND The effectiveness of piperacillin-tazobactam (PTZ) for the treatment of extended-spectrum β-lactamase (ESBL) bacteremia is controversial. We compared 14-day mortality of PTZ vs carbapenems as empiric therapy in a cohort of patients with ESBL bacteremia who all received definitive therapy with a carbapenem. METHODS Patients hospitalized between January 2007 and April 2014 with monomicrobial ESBL bacteremia were included. A decrease of >3 doubling dilutions in the minimum inhibitory concentration for third-generation cephalosporins tested in combination with 4 µg/mL of clavulanic acid was used to confirm ESBL status. The primary exposure was empiric therapy, defined as antibiotic therapy administered to a patient before ESBL status was known. Patients were excluded if they did not receive a carbapenem after ESBL production was identified. The primary outcome was time to death from the first day of bacteremia. Propensity scores using inverse probability of exposure weighting (IPW) were used to estimate the probability that a patient would receive PTZ vs carbapenems empirically. We calculated overall hazard ratios for mortality censored at 14 days using Cox proportional hazards models on an IPW-adjusted cohort. RESULTS A total of 331 unique patients with ESBL bacteremia were identified. One hundred three (48%) patients received PTZ empirically and 110 (52%) received carbapenems empirically. The adjusted risk of death was 1.92 times higher for patients receiving empiric PTZ compared with empiric carbapenem therapy (95% confidence interval, 1.07-3.45). CONCLUSIONS PTZ appears inferior to carbapenems for the treatment of ESBL bacteremia. For patients at high risk of invasive ESBL infections, early carbapenem therapy should be considered. Our findings should not be extended to β-lactam/β-lactamase inhibitor combinations in development, as limited clinical data are available for these agents.

Frequency of Klebsiella pneumoniae Carbapenemase (KPC)-Producing and Non-KPC-Producing Klebsiella Species Contamination of Healthcare Workers and the Environment

We examined contamination of healthcare worker (HCW) gown and gloves after caring for patients with Klebsiella pneumoniae carbapenemase (KPC)-producing and non-KPC-producing Klebsiella as a proxy for horizontal transmission. The rate of contamination with Klebsiella species is similar to that of contamination with methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococcus, with 31 (14%) of 220 of HCW-patient interactions resulting in contamination of gloves and gowns.

Impact of a new vaccine clinic on hepatitis B vaccine completion and immunological response rates in an HIV-positive cohort

INTRODUCTION Hepatitis B virus vaccination (HBVV) in the HIV-infected population has poor reported completion rates and immunological response rates. At our HIV clinic, we established a vaccine clinic to improve HBVV outcomes using interventions such as SMS text reminders and double-dose (DD) HBVV for standard-dose non-responders (SD NRs). METHODS A five-year (2003-2008) retrospective review of the completion rates and immunological response rates for HBVV after the establishment of the dedicated vaccine clinic was conducted. Statistical significance was assumed at p<0.05, and the analysis was performed using SPSS (v16). RESULTS A total of 354 HIV-infected patients were included. Seventy-five percent (268/354) of patients completed the SD HBVV, an 84% (226/268) returned for the hepatitis B surface antibody evaluation. Only 47.3% (107/226) responded to standard-dose hepatitis B vaccination. Responders had higher absolute numbers (p=0.017) and percentages of CD4 cells (p<0.001) and were more likely to be receiving HAART (p=0.001). There was a 70% (48/69) response rate to DD HBVV among SD NRs. On-treatment analysis showed an 88% (155/176) overall immunological response to SD HBVV and DD HBVV, if required. CONCLUSION High HBVV completion and response rates in this HIV cohort were enabled through the use of multiple interventions, including the use of SMS text message reminders and routine referral for DD vaccination.

Factors Associated with Treatment Failure in Vertebral Osteomyelitis Requiring Spinal Instrumentation

ABSTRACT Patients with vertebral osteomyelitis may require instrumentation for spinal stabilization. Determining the optimal duration and type of antimicrobial therapy for these patients is challenging. The aim of this study was to examine risk factors for treatment failure, in particular antimicrobial duration, in a cohort of patients requiring spinal instrumentation for vertebral osteomyelitis. We conducted a retrospective cohort study of all patients with vertebral osteomyelitis who had spinal instrumentation between January 2002 and January 2012 at the University of Maryland Medical Center. The primary outcome measure was treatment failure >4 weeks postoperatively. We identified 131 patients with vertebral osteomyelitis requiring spinal instrumentation, 94 of whom had >4 weeks of follow-up and were included in the primary analysis. Treatment failure occurred in 22 of the 94 patients (23%) at a median of 4 months after surgery. Among patients who failed therapy, 20 of 22 failed within 1 year of surgery. Cervical and thoracic infection sites and the presence of negative cultures were associated with fewer treatment failures. Addition of rifampin and the use of chronic suppressive antimicrobials did not affect treatment failure rate. Twenty-three percent of patients with spinal instrumentation for vertebral osteomyelitis experienced treatment failure. Treatment failure almost always occurred within the first year of spinal instrumentation.

Varicella vaccination in HIV-positive individuals – a time to act

Purpose of the study Primary varicella infection in the HIV population can have serious sequelae. The HIV non-VZV immune population is at risk of attack rates of up to 90% from infected household contacts, who are predominantly children. Universal childhood varicella vaccination is currently under review in Ireland. New recommendations of the Advisory Committee on Immunisation Practices (MMWR) 2007 include expanding the use of varicella vaccine for HIV-infected adults and adolescents with CD4 >200, with vaccination of household contacts of those with CD4<200. These guidelines prompted us to review our HIV patient cohort, 30% of whom are from sub-Saharan Africa (SSA), reflecting the changing demographics of the Irish population. VZV non-immunity is known to be higher in the SSA population.

How frequently are hospitalized patients colonized with carbapenem-resistant Enterobacteriaceae (CRE) already on contact precautions for other indications?

Using samples collected for VRE surveillance, we evaluated unit admission prevalence of carbapenem-resistant Enterobacteriaceae (CRE) perirectal colonization and whether CRE carriers (unknown to staff) were on contact precautions for other indications. CRE colonization at unit admission was infrequent (3.9%). Most CRE carriers were not on contact precautions, representing a reservoir for healthcare-associated CRE transmission.

Comparison of nylon-flocked swab and cellulose sponge methods for carbapenem-resistant Enterobacteriaceae and gram-negative organism recovery from high-touch surfaces in patient rooms

The ideal sampling method and benefit of qualitative versus quantitative culture for carbapenem-resistant Enterobacteriaceae (CRE) recovery in hospitalized patient rooms and bathrooms is unknown. Although the use of nylon-flocked swabs improved overall gram-negative organism recovery compared with cellulose sponges, they were similar for CRE recovery. Quantitative culture was inferior and unrevealing beyond the qualitative results.

Comparing brief, covert, directly observed hand hygiene compliance monitoring to standard methods: A multicenter cohort study

&NA; Hand hygiene compliance is subject to the Hawthorne effect, which may be attenuated by covert observers and brief observation periods. This study demonstrated that hand hygiene compliance rates were between 8% and 29% greater when reported by infection prevention programs than when reported by covert observers over brief observation periods.

Preventability of Hospital Onset Bacteremia and Fungemia: A Pilot Study of a Potential New Indicator of Healthcare-Associated Infections

Abstract Background Central-line associated bloodstream infections (CLABSI) are a subset of hospital-onset bacteremia and fungemia (HOB), a potential indicator of healthcare-associated infections (HAIs) that can be objectively and directly obtained from electronic health records. We undertook a pilot study to elucidate the causes and determine the preventability of HOB. Methods HOB was defined as growth of a microorganism from a blood culture obtained ≥3 calendar days after admission in a hospitalized patient. A random sampling of HOB events across 2 academic hospitals and a pediatric intensive care unit in a third academic hospital were identified between October 1, 2014 and September 30, 2015. Medical records were reviewed to identify potential risk factors and sources of bacteremia. Two physicians used underlying patient factors, microorganism, and other clinical data to rate the preventability of each HOB event in an “ideal hospital” on a 6-point Likert scale. Results Medical records for 60 HOB events (20 in each hospital) were reviewed. The most common organisms were coagulase-negative Staphylococcus (28%) and Candida spp. (17%) (Figure 1). The most likely sources of bacteremia and fungemia included CLABSI (28%) and skin contaminants/commensals (17%) (Figure 2). Forty-nine percent of HOB events not attributed to skin commensals were rated as potentially preventable (Figure 3). Fifty percent of HOB events randomly sampled across 2 hospitals occurred in an intensive care unit. Central venous catheters, urinary catheters, and mechanical ventilation were present in the previous 2 days among 73%, 20%, and 25% of all HOB events, respectively. Only 10% of all HOB events occurred in a patient without an indwelling device. Only 20% of HOB events resulted in a National Healthcare Safety Network (NHSN) reported CLABSI. Conclusion Half of HOB events are potentially preventable in this pilot study. HOB may be an indicator for a large number of preventable HAIs not currently measured by NHSN. Larger studies across a variety of hospital settings are needed assess the generalizability of these results the implications of HOB surveillance for infection prevention practices and patient outcomes. Disclosures All authors: No reported disclosures.

335Infrequent Air Contamination with Acinetobacter baumannii Surrounding Known Colonized/Infected patients

335. Infrequent Air Contamination with Acinetobacter baumannii Surrounding Known Colonized/Infected patients Clare Rock, MD; Anthony D. Harris, MD, MPH; J. Kristie Johnson, PhD; Werner Bischoff; Kerri Thom, MD, MS; Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore, MD; Department of Pathology, University of Maryland School of Medicine, Baltimore, MD; Wake Forest University Baptist Medical Center, North Carolina, NC