Prospective Evaluation of a Hospital Epidemiologist's Activities at a European Tertiary-Care Medical Center

Abstract Objective: Assessment of the distribution of tasks and consultations provided by the hospital epidemiologist (HE) at University Hospital of Zurich (UHZ). Design: Prospective collection of data on hospital epidemiology consultations over a 3-year period (1995-1997). Time spent per consultation and activities of infection control practitioners were not recorded. Setting: A 1,040-bed tertiary-care university hospital in Zurich, Switzerland. Results: Between January 1, 1995, and December 31, 1997, the HE received 1,660 requests for consultation. Advice or action was sought in the following areas: epidemiology (27.5% of requests); quality assurance, including antibiotic utilization and technology assessment (24.8%); infection control and practice guidelines (22.5%); disinfection and sterilization (11.6%); clinical infectious diseases (13.4%). During 1997, 35% of epidemiology consults were related to methicillin-resistant Staphylococcus aureus and 5.8% to tuberculosis. Public or private hospitals not affiliated with UHZ requested 40% of all consults. Conclusions: This study shows that HEs are involved in many different activities. Only 27.5% of hospital epidemiology consultations were directly related to issues of epidemiology. Practical knowledge of the methodologies for continuous quality improvement and assessment of various new technologies is important for HEs. The results of this study may be useful in discussions between HEs and administrators about allocation of resources or issues of reimbursemen

Non-purulent low-grade infection as cause of pain following shoulder surgery: preliminary results

Low-grade infection was systematically searched for in all revision shoulder surgeries by harvesting tissue samples. Ten consecutive patients were identified with a non-purulent low-grade infection of the shoulder. All of these patients suffered from pain and eight were stiff. Preoperative aspiration in eight patients yielded bacterial growth in only one case. Serum C-reactive protein levels were normal in seven out of 10 cases. Propionibacterium acnes was identified in seven, coagulase-negative Staphylococcus in two and Staphylococcus saccharolyticus in one case. The delay between harvesting the tissue samples and detection of bacterial growth averaged eight days (range, 2-17). After debridement and antibiotic treatment for a mean of 4.5 months, tissue samples were repeatedly harvested in nine patients due to persistent pain. The infection was microbiologically eradicated in six out of nine cases that had a repeated biopsy. However, nine out of 10 patients continued to suffer from moderate to severe pain. Low-grade infection of the shoulder can be a cause of persistent pain and stiffness. The results of antibiotic treatment are disappointing. Further studies are necessary to analyse this difficult patholog

Epidemic Spread of a Single Clone of Methicillin-Resistant Staphylococcus aureus among Injection Drug Users in Zurich, Switzerland

We describe an outbreak of methicillin-resistant Staphylococcus aureus (MRSA) among injection drug users (IDUs). From August 1994 through December 1999, we registered 31 IDUs with MRSA infections (12 with soft-tissue infection, 7 with pneumonia [fatal in 1], 7 with endocarditis [fatal in 1], 2 with osteomyelitis, 2 with septic arthritis, and 1 with ulcerative tonsillitis), with a marked increase in the number of IDUs registered during 1998 and 1999. Of 31 patients, 15 (48%) were infected with human immunodeficiency virus. A point-prevalence study among IDUs who frequented outpatient facilities in Zurich revealed an MRSA carriage rate of 10.3% (range, 0%-28.6%) in various facilities. In all but 1 case, pulsed-field gel electrophoresis banding patterns of isolates obtained from these patients were indistinguishable from isolates of the initial 31 IDUs registered. Risk factors for MRSA carriage were disability and prior hospitalization in a hospice. In summary, MRSA became endemic in IDUs in Zurich as a result of the spread of a single clone. This clone caused major morbidity and was responsible for a lethal outcome in 2 case

Rapid Colonization with Methicillin-Resistant Coagulase-Negative Staphylococci After Surgery

Background: Antimicrobial resistance may compromise the efficacy of antibiotic prophylaxis before surgery. The aim of this study was to measure susceptibility and clonal distribution of coagulase-negative staphylococci (CoNS) colonizing the skin around the surgery access site before and after the procedure. Methods: From March to September 2004, a series of 140 patients undergoing elective major abdominal surgery were screened for CoNS colonization at admission and 5days after surgery. All isolates were tested for antibiotic susceptibility and genotyped by pulsed-field gel electrophoresis (PFGE). Results: Colonization rates with CoNS at admission and after surgery were 85% and 55%, respectively. The methicillin-resistant CoNS rate increased from 20% at admission to 47% after surgery (P=0.001). The PFGE pattern after surgery revealed more patients colonized with identical clones: 8/140 patients (8/119 strains) and 26/140 patients (26/77 strains), respectively (P<0.001). Conclusions: Our results suggest rapid recolonization of disinfected skin by resistant nosocomial CoNS. Larger studies, preferably among orthopedic or cardiovascular patients, are required to clarify whether standard antibiotic prophylaxis with first- or second-generation cephalosporins for CoNS infections may be compromised if the patient requires an additional intervention 5days or more after the initial surger

Etiologic Diagnosis of Infective Endocarditis by Broad-Range Polymerase Chain Reaction: A 3-Year Experience

We analyzed surgically resected endocardial specimens from 49 patients by broad-range PCR. PCR results were compared with (1) results of previous blood cultures, (2) results of culture and Gram staining of resected specimens, and (3) clinical data (Duke criteria). Molecular analyses of resected specimens and previous blood cultures showed good overall agreement. However, in 18% of patients with sterile blood cultures, bacterial DNA was found in the resected materials. When data from patients with definite or rejected cases of infective endocarditis (IE) were included, the sensitivity, specificity, and positive and negative predictive values of broad-range PCR were 82.6%, 100%, 100%, and 76.5%, respectively, overall, and 94.1%, 100%, 100%, and 90%, for cases of native valve endocarditis. The sensitivity, specificity, and positive and negative predictive values of culture of resected specimens from patients with native valve endocarditis were 17.6%, 88.9%, 75%, and 36.4%. We recommend broad-range PCR of surgically resected endocardial material in cases of possible IE, in cases of suspected IE in which blood cultures are sterile, and in cases in which organisms grow in blood cultures but only Duke minor criteria are met. We propose to add molecular techniques to the pathologic criteria of the Duke classification schem

Stratification of cumulative antibiograms in hospitals for hospital unit, specimen type, isolate sequence and duration of hospital stay

Background Empirical antibiotic therapy is based on patients' characteristics and antimicrobial susceptibility data. Hospital-wide cumulative antibiograms may not sufficiently support informed decision-making for optimal treatment of hospitalized patients. Methods We studied different approaches to analysing antimicrobial susceptibility rates (SRs) of all diagnostic bacterial isolates collected from patients hospitalized between July 2005 and June 2007 at the University Hospital in Zurich, Switzerland. We compared stratification for unit-specific, specimen type-specific (blood, urinary, respiratory versus all specimens) and isolate sequence-specific (first, follow-up versus all isolates) data with hospital-wide cumulative antibiograms, and studied changes of mean SR during the course of hospitalization. Results A total of 16 281 isolates (7965 first, 1201 follow-up and 7115 repeat isolates) were tested. We found relevant differences in SRs across different hospital departments. Mean SRs of Escherichia coli to ciprofloxacin ranged between 64.5% and 95.1% in various departments, and mean SRs of Pseudomonas aeruginosa to imipenem and meropenem ranged from 54.2% to 100% and 80.4% to 100%, respectively. Compared with hospital cumulative antibiograms, lower SRs were observed in intensive care unit specimens, follow-up isolates and isolates causing nosocomial infections (except for Staphylococcus aureus). Decreasing SRs were observed in first isolates of coagulase-negative staphylococci with increasing interval between hospital admission and specimen collection. Isolates from different anatomical sites showed variations in SRs. Conclusions We recommend the reporting of unit-specific rather than hospital-wide cumulative antibiograms. Decreasing antimicrobial susceptibility during hospitalization and variations in SRs in isolates from different anatomical sites should be taken into account when selecting empirical antibiotic treatmen

Clearance of an epidemic clone of methicillin-resistant Staphylococcus aureus in a drug-use network: A follow-up study in Switzerland

Background: A single clone of methicillin-resistant Staphylococcus aureus (MRSA) was observed in a drug-use network starting in 1994, and was found to persist throughout 2001, with up to 19% MRSA colonization of intravenous drug users (IDUs). Recent clinical observations have shown low prevalences of this endemic drug clone among MRSA isolates. The goal of this study was to assess the evolution of MRSA carriage among IDUs. Methods: The survey took place from November 2008 to September 2009. Ten drug dispensary facilities took part. Demographic and clinical data including sex, history of MRSA, past hospitalization, use of antibiotics, and presence of wounds were collected. Screening of the nares, throat, and wounds was done. Results: Five hundred and fourteen swab specimens were obtained; 497 of them were nose/throat samples and 17 were wound swabs. MRSA was identified in 5 samples (1%). Four MRSA were found in nose/throat samples and 1 in a wound swab. Pulsed-field gel electrophoresis typing of the MRSA isolates revealed 2 different common endemic types: 4 were identified as the Zurich IDU clone and 1 as the Grison clone. Conclusions: The study shows a significant decline of MRSA colonization among IDUs. The underlying causes for this decline could not be determined fully, but we hypothesize a bundle of interventions as contributing: enhanced medical care, better wound management, isolation management, teaching IDUs basic hygiene techniques, and the national 'Four Pillars' policy. Hospital epidemiological policies such as pre-emptive isolation, length of isolation time, and screening procedures were adapted accordingly

Prevalence and Risk Factors for Nosocomial Infections in Four University Hospitals in Switzerland

Abstract Objective: To determine the prevalence and risk factors for nosocomial infections (NIs) in four Swiss university hospitals. Design and Setting: A 1-week period-prevalence survey conducted in May 1996 in medical, surgical, and intensive-care wards of four Swiss university hospitals (900-1,500 beds). Centers for Disease Control and Prevention definitions were used, except that asymptomatic bacteriuria was not categorized as NI. Study variables included patient demographics, primary diagnosis, comorbidities, exposure to medical and surgical risk factors, and use of antimicrobials. Risk factors for NIs were determined using logistic regression with adjustment for length of hospital stay, study center, device use, and patients' comorbidities. Results: 176 NI were recorded in 156 of 1,349 screened patients (11.6%; interhospital range, 9.8%-13.5%). The most frequent NI was surgical-site infection (53; 30%), followed by urinary tract infection (39; 22%), lower respiratory tract infection (27; 15%), and bloodstream infection (23; 13%). Prevalence of NI was higher in critical-care units (25%) than in medical (9%) and surgical wards (12%). Overall, 65% of NIs were culture-proven; the leading pathogens were Enterobacteriaceae (44; 28%), Staphylococcus aureus (20; 13%), Pseudomonas aeruginosa (17; 11%), and Candida species (16; 10%). Independent risk factors for NI were central venous catheter (CVC) use (odds ratio [OR], 3.35; 95% confidence interval [CI95], 2.91-3.80), admission to intensive care (OR, 1.75; CI95, 1.30-2.21), emergency admission (OR, 1.57; CI95, 1.15-2.00), impaired functional status (Karnofsky index 1-4: OR, 2.56; CI95, 1.95-3.17), and McCabe classification of ultimately fatal (OR, 2.50; CI95, 2.04-2.96) or rapidly fatal (OR 2.25; CI95,1.52-2.98) underlying condition. Conclusions: According to the results of this survey, NIs are frequent in Swiss university hospitals. This investigation confirms the importance of CVCs as a major risk factor for NI. Patient comorbidities must be taken into account to adjust for case mix in any study comparing interhospital or intrahospital infection rate