Jeffrey Topal

Correlation between healthcare workers' knowledge of influenza vaccine and vaccine receipt.

OBJECTIVE Influenza vaccine receipt by healthcare workers (HCWs) is important because HCWs are at risk for occupational exposure to influenza and may act as vectors in the nosocomial transmission of influenza. HCWs were surveyed to determine whether belief in commonly held influenza vaccine misconceptions was associated with influenza vaccine acceptance. DESIGN Cross-sectional study. SETTING A large urban teaching hospital. METHOD A self-administered survey was used to assess nursing and physician staff influenza vaccine knowledge, current vaccination status, and potential reasons for vaccine declination. RESULTS Two hundred twelve of 215 surveys were completed. The overall influenza vaccination rate was 73%. Physician staff were significantly more likely to have been vaccinated compared with nursing staff (82% vs 62%, respectively; P = .0009). HCWs answering the 5 influenza vaccine basic knowledge questions correctly were significantly more likely to have been vaccinated than those responding incorrectly to any question (84% vs 64%, respectively; P = .002). This association was present in the nursing group where 80% of those answering the knowledge questions correctly were vaccinated, but only 49% of those answering incorrectly were vaccinated (P = .000005). However, in the physician group, there was no significant difference in the influenza vaccination rates between those answering correctly and those answering incorrectly (P = .459). CONCLUSION Belief in commonly held influenza vaccine misconceptions was significantly associated with influenza vaccine declination among nursing staff and may act as a barrier to greater rates of influenza vaccination. Reasons for influenza vaccine nonreceipt may differ between nursing and physician staff.

Prevention of Nosocomial Catheter-Associated Urinary Tract Infections Through Computerized Feedback to Physicians and a Nurse-Directed Protocol

Catheter-associated urinary tract infections (CAUTIs) represent the most common nosocomial infection. The authors’ baseline rate of CAUTI for general medical service was elevated at 36 per 1000 catheter-days. The medical literature has consistently linked inappropriate catheter use with the development of CAUTI. The baseline data also revealed a high rate of inappropriate use of indwelling urinary catheters. Using the dual modalities of technology through prompts in the computerized order/entry system and handheld bladder scanners, as well as in combination with staff education and nurse empowerment, the authors were successful in reducing the use and duration of urinary catheters as well as the incidence of CAUTI. In subsequent data collection cycles over the following 2 years, 81% reduction in device use and a 73% reduction in the clinical end point of nosocomial CAUTI (36/1000 catheter-days to 11/1000 catheter-days; P < .001) was demonstrated.

High prevalence of antibiotic-resistant bacterial infections among patients with cirrhosis at a US liver center.

BACKGROUND & AIMS There are limited data on the prevalence or predictors of antibiotic-resistant bacterial infections (AR-BI) in hospitalized patients with cirrhosis in North America. Exposure to systemic antibiotics is a risk factor for AR-BI; however, little is known about the effects of the increasingly used oral nonabsorbed antibiotics. METHODS We analyzed data from patients with cirrhosis and bacterial infections hospitalized in a liver unit at a US hospital between July 2009 and November 2010. Multivariate logistic regression was used to determine predictors of AR-BI. Data were analyzed on the first bacterial infection of each patient (n = 115), and a sensitivity analysis was performed on all infectious episodes per patient (n = 169). RESULTS Thirty percent of infections were nosocomial. Urinary tract infections (32%) and spontaneous bacterial peritonitis (24%) were most common. Of the 70 culture-positive infections, 33 (47%) were found to be antibiotic resistant (12 were vancomycin-resistant Enterococci, 9 were extended-spectrum β-lactamase-producing Enterobacteriaceae, 7 were quinolone-resistant gram-negative rods, and 5 were methicillin-resistant Staphylococcus aureus). Exposure to systemic antibiotics within 30 days before infection was associated independently with AR-BI, with an odds ratio (OR) of 13.5 (95% confidence interval [CI], 2.6-71.6). Exposure to only nonabsorbed antibiotics (rifaximin) was not associated with AR-BI (OR, 0.4; 95% CI, 0.04-2.8). In a sensitivity analysis, exposure to systemic antibiotics within 30 days before infection and nosocomial infection was associated with AR-BI (OR, 5.2; 95% CI, 1.5-17.7; and OR, 4.2; 95% CI, 1.4-12.5, respectively). CONCLUSIONS The prevalence of AR-BI is high in a US tertiary care transplant center. Exposure to systemic antibiotics within 30 days before infection (including those used for prophylaxis of spontaneous bacterial peritonitis), but not oral nonabsorbed antibiotics, is associated with development of an AR-BI.

Successful use of intraperitoneal daptomycin in the treatment of vancomycin-resistant enterococcus peritonitis.

Peritoneal dialysis-associated peritonitis from such resistant organisms as vancomycin-resistant enterococci increasingly is occurring and is challenging to treat. We describe 2 cases of vancomycin-resistant entercoccus peritonitis successfully treated with intraperitoneal daptomycin. Both patients were on automated peritoneal dialysis therapy with culture-positive vancomycin-resistant Enterococcus faecium peritonitis and were treated with 10 to 14 days of intraperitoneal daptomycin given every 4 hours through manual peritoneal dialysate exchanges. Despite the known degradation in dextrose solutions, intraperitoneal daptomycin was effective in clearing both infections. Neither patient experienced a relapse or repeated peritonitis. Additional studies of dosing and pharmacokinetics of intraperitoneal daptomycin in the treatment of patients with vancomycin-resistant enterococcus peritonitis are needed.

Evaluation of Biosite Triage Clostridium difficile Panel for Rapid Detection of Clostridium difficile in Stool Samples

ABSTRACT One hundred two stool samples were tested by both the rapid TriageClostridium difficile Panel (Triage Panel) and the cytotoxin cell culture assay. Five samples positive by both theC. difficile toxin A (Tox A) and common antigen components of the Triage Panel had cytotoxin titers of ≥10,000. Twenty-three samples were Triage Panel Tox A negative but common antigen positive. Ten of these had cytotoxin titers of 10 to 1,000, but 13 were cytotoxin negative. Bacterial isolates obtained from 8 of these 13 specimens were analyzed for Tox A and B genes by PCR, and only two contained toxigenic bacteria. Thus, the majority of samples positive only for C. difficile common antigen contained nontoxigenic bacteria. A Triage Panel Tox A-positive result indicated a sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 33.3, 100, 100, and 88.2%, respectively. A Triage Panel common antigen-positive result indicated a sensitivity, specificity, PPV, and NPV of 100, 82.7, 53.6, and 100%, respectively. The high NPV of the Triage Panel common antigen, together with rapid reporting of results, should prove useful in avoiding unnecessary use of contact precautions and antibiotic treatment for C. difficile-negative patients. However, with Triage Panel common antigen-positive patients, a sensitive cytotoxin assay should be used to distinguish true cytotoxin-positive patients from C. difficile carriers.

Telavancin for refractory methicillin-resistant Staphylococcus aureus bacteremia and infective endocarditis.

Abstract Background: Methicillin-resistant Staphylococcus aureus (MRSA) bacteremia and infective endocarditis (IE) have become increasingly difficult to treat over the past decade, with suboptimal response rates of less than 50%. Although vancomycin and daptomycin are standard therapeutic options, treatment failures with either or both agents are common. Telavancin is a lipoglycopeptide antibiotic with activity against MRSA. In vitro, telavancin displays bactericidal activity and has lower minimum inhibitory concentrations to MRSA than vancomycin. Methods: We present a retrospective, case-series report of 14 patients treated with telavancin for refractory MRSA bacteremia with and without IE at our institution from 9 September 2010 to 2 April 2012. Results: Of the 14 patients who received telavancin for refractory MRSA bacteremia and IE, eight survived their inpatient admission and were able to be followed for 30 days. The overall survival rate was 57% (n = 8). Of the eight surviving patients, five were diagnosed with MRSA IE and the remaining three were diagnosed with complicated MRSA bacteremia. All six patients who did not survive the inpatient admission were diagnosed with left-sided IE involving the mitral valves. Conclusions: This retrospective case series provides clinical evidence for the use of telavancin as a treatment option for refractory MRSA bacteremia and IE. With limited effective agents in the treatment of MRSA-complicated bacteremia and IE, telavancin represents a potential treatment option. Further randomized, controlled trials are necessary to define the optimal role of telavancin in the treatment of MRSA bacteremia and IE.

Development of echinocandin-resistant Candida albicans candidemia following brief prophylactic exposure to micafungin therapy

Empiric antifungal coverage is indicated in patients with graft‐versus‐host disease (GVHD) following a stem cell transplant (SCT) who are febrile and neutropenic for extended periods of time. Empiric antifungal coverage is indicated for patients with hematologic malignancies who have persistent fever and neutropenia as well as patients who have GVHD following SCT. Although the prophylactic use of antifungals is a cornerstone of the care for such patients, the selection of the particular antifungal is at the discretion of the clinician. We report a patient case whose surveillance blood cultures obtained 14 days after the switch from voriconazole to micafungin were positive for the growth of Candida albicans. Clinicians prescribing echinocandin therapy for antifungal prophylaxis must be aware of the risks of echinocandin resistance and possible breakthrough candidemia with C. albicans.

Vancomycin‐Induced Thrombocytopenia Without Isolation of a Drug‐Dependent Antibody

Vancomycin is a glycopeptide antibiotic used in the treatment of gram‐positive infections including methicillin‐resistant Staphylococcus aureus (MRSA). The most common adverse reaction to vancomycin is red man syndrome, which is a histaminergic reaction causing a rash on the upper torso, neck, and face after rapid infusion of the drug. Less commonly, vancomycin has been associated with thrombocytopenia. The etiology is believed to be the induction of drug‐dependent antibodies, which in turn cause immune‐mediated destruction of platelets. We describe a 41‐year‐old man who received two courses of vancomycin for the treatment of MRSA pneumonia and then experienced a decline in platelet count to a nadir of 15 x 103/mm3. Vancomycin was discontinued, doxycycline was started, and the patients platelet count rebounded over the next 6 days. The patient was readmitted to the hospital 2 months later for MRSA bacteremia and was rechallenged with vancomycin. He again experienced a decline in platelet count. Vancomycin was discontinued, and daptomycin was started. The patients platelet count rebounded to normal levels over the next 5 days. Although the patient experienced acute thrombocytopenia after vancomycin exposure, no bleeding complications occurred, and the patients platelet count rebounded to normal after the discontinuation of vancomycin. The patient had no other known risk factors for the development of rapid thrombocytopenia. Use of the Naranjo adverse drug reaction probability scale indicated a definite relationship (score of 9) between the patients development of thrombocytopenia and vancomycin therapy. Although vancomycin was the presumed cause of thrombocytopenia in this patient, no drug‐dependent antibody was isolated from blood samples collected after both exposures to vancomycin (analyzed by using a screening assay to identify drug‐dependent antibodies to vancomycin [developed by the BloodCenter of Wisconsin]). Although the evidence supporting vancomycin induction of antibody‐mediated destruction of platelets was lacking, further studies delineating alternate mechanisms of platelet destruction are warranted. Therefore, even in the absence of a positive antibody test, vancomycin should still be considered in the differential diagnosis as a cause of drug‐induced thrombocytopenia.

Call for Antimicrobial Stewardship in Solid Organ Transplantation

To the Editor:We read with interest the recently published InfectiousDisease Guidelines of the American Society of Transplan-tation (AST), and commend the Infectious DiseasesCommunity of Practice for the timely release of thesecomprehensive guidelines (1). We are disappointed,however, to see that a cohesive approach to developingan antimicrobial stewardship program (ASP) within thetransplant community was not described. ASPs can have apositive impact on limiting the prevalence of multidrugresistant (MDR) infections, a focus of several of the newguidelines. Transplant recipients are disproportionatelyaffected by MDR bacteria, with prolonged exposure tobroad-spectrum antimicrobial agents often present as thesole risk factor for their development (2).Numerous studies have shown that various stewardshipinterventions are able to decrease inappropriate use ofantimicrobialsandlimittheriseofresistantbacteriawithoutaconcomitant decline in clinical outcomes (3). While theimpact of ASPs in a transplant-specific population has notbeen formally evaluated, hospital-level and multicenterstudies evaluating the impact of ASPs frequently includesolid organ transplant recipients as part of their targetpopulation. Additionally, the benefit of ASPs in limiting therise of MDR bacteria may extend as collateral benefit totransplant patients, as admission to rooms that werepreviouslyoccupiedbypatientscolonizedwithMDRbacteriahas been shown to be an independent risk factor for theacquisition of MDR bacteria by subsequent patients (4).The Infectious Diseases Society of America, Society forHealthcare Epidemiology of America and Pediatric Infec-tious Diseases Society have recently released a positionstatement calling for mandatory implementation of ASPsthroughout the healthcare system (5). We believe that thetransplant community is a key stakeholder in this mandate,serving a patient population that is likely to derive thegreatest benefit from its implementation. Through formalguidance and recommendations to its members on theimplementation of antimicrobial stewardship, we believethat AST can have a lasting, positive impact on the well-being of the patients it serves. We call upon AST to adoptcomprehensive guidelines for antimicrobial stewardship tofurther this goal.S. L. Aitken

Comparison of Simplexa Universal Direct PCR with Cytotoxicity Assay for Diagnosis of Clostridium difficile Infection: Performance, Cost, and Correlation with Disease

ABSTRACT Simplexa Clostridium difficile universal direct PCR, a real-time PCR assay for the detection of the C. difficile toxin B (tcdB) gene using the 3M integrated cycler, was compared with a two-step algorithm which includes the C. Diff Chek-60 glutamate dehydrogenase (GDH) antigen assay followed by cytotoxin neutralization. Three hundred forty-two liquid or semisolid stools submitted for diagnostic C. difficile testing, 171 GDH antigen positive and 171 GDH antigen negative, were selected for the study. All samples were tested by the C. Diff Chek-60 GDH antigen assay, cytotoxin neutralization, and Simplexa direct PCR. Of 171 GDH-positive samples, 4 were excluded (from patients on therapy or from whom duplicate samples were obtained) and 88 were determined to be true positives for toxigenic C. difficile. Of the 88, 67 (76.1%) were positive by the two-step method and 86 (97.7%) were positive by PCR. Seventy-nine were positive by the GDH antigen assay only. Of 171 GDH antigen-negative samples, none were positive by PCR. One antigen-negative sample positive by the cytotoxin assay only was deemed a false positive based on chart review. Simplexa C. difficile universal direct PCR was significantly more sensitive for detecting toxigenic C. difficile bacteria than cytotoxin neutralization (P = 0.0002). However, most PCR-positive/cytotoxin-negative patients did not have clear C. difficile disease. The estimated cost avoidance provided by a more rapid molecular diagnosis was outweighed by the cost of isolating and treating PCR-positive/cytotoxin-negative patients. The costs, clinical consequences, and impact on nosocomial transmission of treating and/or isolating patients positive for toxigenic C. difficile by PCR but negative for in vivo toxin production merit further study.