Andreas F Widmer

• Universitätsspital Basel

The implementation of isolation precautions for patients with suspected Coronavirus Disease 2019 (COVID-19) and pending test results is resource intensive. Due to the limited availability of single-bed rooms at our institution, we isolated patients with suspected COVID-19 together with patients without suspected COVID-19 on-site in multiple-bed roo...

Importance Preoperative skin antisepsis is an established procedure to prevent surgical site infections (SSIs). The choice of antiseptic agent, povidone iodine or chlorhexidine gluconate, remains debated. Objective To determine whether povidone iodine in alcohol is noninferior to chlorhexidine gluconate in alcohol to prevent SSIs after cardiac or...

Background Most surveillance systems for catheter-related bloodstream infections (CRBSI) and central line-associated bloodstream infections (CLABSI) are based on manual chart review. Our objective was to validate a fully automated algorithm for CRBSI and CLABSI surveillance in intensive care units (ICU). Methods We developed a fully automated algo...

Aims: This study evaluated an approach to establishing a comprehensive nationwide surveillance system for Clostridioides difficile infection in Switzerland. We report the results of patient-related surveillance and calculate the incidence rate of C. difficile infection in Switzerland in 2022. Methods: Initiated in 2017 by the National Centre for...

Background In Switzerland, the national surgical site infection (SSI) surveillance program showed a modest decrease in SSI rates for different procedures over the last decade. The study aimed to determine whether a multimodal, targeted intervention program in addition to existing SSI surveillance is associated with decreased SSI rates in the partic...

The silent pandemic of bacterial antimicrobial resistance is a leading cause of death worldwide, prolonging hospital stays and raising health-care costs. Poor incentives to develop novel pharmacological compounds and the misuse of antibiotics contribute to the bacterial antimicrobial resistance crisis. Therapeutic drug monitoring (TDM) based on blo...

Importance: World Health Organization guidelines recommend administering surgical antimicrobial prophylaxis (SAP), including cefuroxime, within 120 minutes prior to incision. However, data from clinical settings supporting this long interval is limited. Objective: To assess whether earlier vs later timing of administration of cefuroxime SAP is a...

Importance: Antibiotics are commonly prescribed in primary care, increasing the risk of antimicrobial resistance in the population. Objective: To investigate the effect of quarterly audit and feedback on antibiotic prescribing among primary care physicians in Switzerland with medium to high antibiotic prescription rates. Design, setting, and pa...

In >100,000 observations across Swiss acute-care hospitals, hand hygiene (HH) adherence significantly increased during the first coronavirus disease 2019 (COVID-19) wave. However, despite persisting COVID-19 activity, HH adherence returned to prepandemic levels over a 2-year observation period. These results indicate that training and support remai...

Structured summery Background Cephalosporins are recommended for prophylaxis before transcatheter aortic valve replacement (TAVR). Infective endocarditis (IE) after TAVR is caused by enterococci in up to 30%, especially early after TAVR. Enterococcal colonization in the groin has been postulated as a source of infection, not only because prophylax...

Background: The source of transmission of Clostridioides difficile in healthcare institutions is frequently unknown. The aim of this prospective cohort study was to assess the association between strains cultured from patients and shoe soles of healthcare workers (HCW), as already shown in the operation theatre, but not on general hospital wards in...

Background The optimal extent of screening of contact patients (CoPat) after exposure to patients infected or colonized with vancomycin-resistant enterococci (VRE) remains controversial. Methods We retrospectively developed a new risk stratification for screening patients exposed to VRE, based on data from three outbreaks—two with Enterococcus fae...

Importance Many guidelines recommend a weight-adopted dose increase of cefuroxime for surgical antimicrobial prophylaxis (SAP). However, the evidence that this approach is associated with lower rates of surgical site infection (SSI) is limited. Objective To assess whether double-dose cefuroxime SAP was associated with a decreased SSI rate in patie...

The proportion of asymptomatic carriers of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains elusive and the potential benefit of systematic screening during the SARS-CoV-2-pandemic is controversial. We investigated the proportion of asymptomatic inpatients who were identified by systematic screening for SARS-CoV-2 upon hospital...

Background The hospital environment has got more attention as evidence as source for bacterial transmission and subsequent hospital-acquired infection increased. Regular cleaning and disinfection have been proposed to lower the risk of infection, in particular for gram-positive bacteria. Auto-disinfecting surfaces would allow to decrease survival o...

Background Conflicting results have been published on the impact of contact precautions (CP) on reduction of transmission of multidrug-resistant microorganisms (MDROs) in the endemic setting. Ambiguous definitions coupled with low adherence partly explain these differences. Aim We prospectively monitored the level of adherence to CP and aimed to r...

Background Accessibility to alcohol-based handrub (ABHR) dispenser is crucial to improve compliance to hand hygiene (HH), being offered as wall-mounted dispensers (ABHR-Ds), and/or pocket bottles. Nevertheless, information on the distribution and density of ABHR-Ds and their impact on HH have hardly been studied. Institutions such as the World Heal...

Objectives Changing microorganism distributions and decreasing antibiotic susceptibility with increasing length of hospital stay have been demonstrated for the colonization or infection of selected organ systems. We wanted to describe microorganism distribution or antibiotic resistance in bacteremia according to duration of the hospitalization usin...

We report the first documented in-hospital patient-to-patient-transmission of a bla VIM-2 integron between isolates of Pseudomonas alcaligenes and P. aeruginosa . Molecular typing looking only for difference within species may fail to detect nosocomial transmission of resistance genes.

Introduction Antibiotic consumption is highest in primary care, and antibiotic overuse furthers antimicrobial resistance. In our recently published pilot-RCT, we used monthly aggregated claims data to provide personalized antibiotic prescription feedback to general practitioners (GPs). The pilot-RCT has shown that personalized prescription feedback...

Background The World Health Organization (WHO) recommends administration of surgical antimicrobial prophylaxis (SAP) in cesarean section prior to incision to prevent surgical site infections (SSI). This study aimed to determine whether SAP administration following cord clamping confers an increased SSI risk to the mother. Methods Study design: Coh...

Objectives Detecting SARS‐CoV‐2 is key to clinical and epidemiological assessment of CoVID‐19. We cross‐validated manual and automated high‐throughput testing for SARS‐CoV‐2‐RNA, evaluated SARS‐CoV‐2‐loads in nasopharyngeal‐oropharyngeal swabs (NOPS), lower respiratory‐fluids, and plasma, and analyzed detection rates after lockdown‐ and relaxation‐...

Purpose: The administration of antimicrobial prophylaxis (AMP) for postoperative urinary tract infections (UTIs) following transurethral resection of bladder tumors (TURB) is controversial. We aimed to systematically review evidence on the potential effect of AMP on postoperative UTI and asymptomatic bacteriuria (ABU). Materials and methods: We...

This prospective observational study evaluated the safety and feasibility of a low threshold testing process in a Triage and Test Center (TTC) during the early course of the coronavirus disease 19 (COVID-19) pandemic. In addition, we aimed to identify clinical predictors for a positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sw...

Public health authorities in the United States and Europe recommend surveillance for Clostridioides difficile infections among hospitalized patients, but differing diagnostic algorithms can hamper comparisons between institutions and countries. We compared surveillance based on detection of C. difficile by PCR or enzyme immunoassay (EIA) in a natio...

Background: Preoperative skin antisepsis is an essential component of safe surgery. However, it is unclear how many antiseptic paints are needed to eliminate bacteria prior to incision. This study compared microbial skin counts after two and three antiseptic paints. Methods: We conducted a prospective cohort study in non-emergency patients recei...

Purpose Although photoselective laser vaporisation of the prostate (PVP) is a recognised alternative to transurethral resection in treating benign prostatic obstruction, there is limited data on the incidence and determinants of postoperative urinary tract infections (UTI). We assessed patients subjected to PVP, evaluating incidence and potential d...

Background Healthcare-associated infections (HAI) lead to high morbidity and mortality. Data for HAIs in psychiatric hospitals are scarce, and not deriving from long-term surveillance. Aim We aimed to assess the impact of an infection control service on the prevalence of HAI in a psychiatric hospital during an 18-year period. Methods In 1999, a p...

Objectives Implementation of effective infection prevention and control (IPC) measures is needed to support global capacity building to limit transmission of coronavirus disease 2019 (COVID-19) and mitigate its impact on health systems. We assessed the perceptions of healthcare workers on the current global IPC preparedness measures for COVID-19. M...

Background: The anaerobe Parvimonas micra is usually recovered as part of the normal flora or in polymicrobial infections of odontogenic or gastrointestinal origin. P. micra has rarely been described as the causative organism of pyogenic spondylodiscitis. Here we report multiple cases of spondylodiscitis caused by this organism and compare their c...

Background Healthcare workers (HCWs) and non-HCWs may contribute to the transmission of influenza-like illness (ILI) to colleagues and susceptible patients by working while sick (presenteeism). The present study aimed to explore the views and behavior of HCWs and non-HCWs towards the phenomenon of working while experiencing ILI. Methods The study...

Background: The necessity of antibiotic prophylaxis for postoperative urinary tract infections (UTIs) after transurethral resection of bladder tumours is controversial. This potentially leads to the overuse of antibiotic prophylaxis and rising antimicrobial resistance rates. The objective of this systematic review and meta-analysis is to compare t...

Background To gain further insights into health care workers (HCWs) attitudes toward influenza vaccination to guide future interventions to increase vaccination rates. Methods A standardized anonymous questionnaire was sent to all employees of the University Hospital Basel, Switzerland following the influenza season 2013/2014. We collected informa...

We report an influenza outbreak in a 75‐bed rehabilitation centre and present the detailed microeconomic impact that it had during the season 2016/2017. The direct medical, direct non‐medical and indirect costs were calculated. The outbreak included 18 patients with influenza and 8 contact patients, leading to 86 days with isolation precautions. Du...

Purpose The length of neutropenia has a significant impact on the incidence of bloodstream infection (BSI) in cancer patients, but limited information is available about the pathogen distribution in late BSI. Methods Between 2002 and 2014, BSI episodes in patients with neutropenia receiving chemotherapy for hematologic malignancies were prospectiv...

Background: Bloodstream infection (BSI) remains a serious complication in patients with hematologic malignancies and neutropenia. The risk factors for mortality after BSI and the contributions of BSI pathogens to mortality remain incompletely understood. Methods: We evaluated first BSI among adult neutropenic patients undergoing high-dose chemot...

The original article [1] contains several mentions of a potentially misleading assertion which the authors would like to clarify; each mention relating to LCMV needlestick injury and its potential capacity for injury.

Candida auris (C. auris) is an emerging fungal pathogen causing invasive infections and outbreaks that have been difficult to control in healthcare facilities worldwide. There is a lack of current evidence for pragmatic infection prevention and control recommendations. The aim of this paper was to review the epidemiology of C. auris and identify be...

Health insurance status may affect the risk for surgical site infection (SSI). A large prospective cohort study in a Swiss tertiary-care hospital did not find evidence of a difference in SSI risk in individuals with basic versus semiprivate or private insurance in a setting with universal health insurance coverage.

Background Needlestick accidents while handling of infectious material in research laboratories can lead to life-threatening infections in laboratory personnel. In laboratories working with the lymphocytic choriomeningitis virus (LCMV), the virus can be transmitted to humans through needlestick injury and lead to serious acute illness up to meningi...

Objectives We aimed to quantify the shared information between medical diagnoses of an adult inpatient population to explore both multimorbidity patterns and vice versa the unrelatedness of medical diagnoses. Study Design and Setting This was a cross-sectional study, performed at a tertiary care center in Switzerland. Diagnoses were routinely code...

We evaluated the improved sensitivity and time to detection of new resin-based blood culture (BC) media in Staphylococcus aureus bloodstream infection. We observed a significantly longer duration of bacteremia and shorter time to detection compared to traditional charcoal-based BC media, which may influence diagnostic work-up and treatment duration...

Afternoon aortic valve replacement surgery may provide perioperative myocardial protection and improve patient outcomes compared with morning surgery. The results of our large observational study based on Swiss cardiac surgical site infection surveillance data suggest that the current evidence is insufficient to generally promote afternoon cardiac...

Background Infestations with scabies mites are a global burden affecting individuals of all ages, classes and ethnicities. As poor sanitation and overcrowding favor the transmission of this highly contagious disease, epidemic outbreaks are frequently observed among displaced persons and asylum seekers. Due to the growing influx of refugees during t...

Objectives: Our goal was to determine the optimal timing and choice of surgical antimicrobial prophylaxis (SAP) in patients having cardiac surgery. Methods: The setting was the Swiss surgical site infection (SSI) national surveillance system with a follow-up rate of >94%. Participants were patients from 14 hospitals who had cardiac surgery from...

Background Transurethral resection of the prostate (TURP) and Greenlight laser vaporisation (GL) of the prostate are frequently performed urological procedures. For TURP, a single-dose antimicrobial prophylaxis (AP) is recommended to reduce postoperative urinary tract infections. So far, no international recommendations for AP have been established...

This nation-wide survey on the epidemiology of vancomycin-resistant enterococci (VRE) included 142 healthcare institutions and showed an increasing number of VRE colonizations and infections in Switzerland, probably for the most part due to nosocomial dissemination. The introduction and spread of a new clone, gaps in VRE screening policies as well...

Objectives To estimate the incidence and epidemiology of catheter-related bloodstream infections (CRBSIs) on a national scale by using prospective epidemiological data from the Swiss Antibiotic Resistance Surveillance System (ANRESIS). Design Observational study. Setting National surveillance from 2008 to 2015 of acute hospitals in Switzerland....

Background Surgical site infections (SSIs) are infrequently observed after joint replacement surgery but have devastating consequences. Since 2009, a large network of Swiss hospitals prospectively collects data for the national SSI surveillance system. The aim of this observational study was to identify risk factors for SSI among patients undergoin...

Background Conflicting results have been published on the impact of contact precautions, as outlined by CDC, HIPAC and ESCMID guidelines, on reduction of transmission of multidrug-resistant organisms (MDRO). Ambiguous definitions coupled with low adherence to these partly explain the differences on impact of contact precautions on transmission of M...

Background Little is known about actual hospital earnings in patients with and without surgical site infections (SSI) under a prospective payment system. To exemplify respective financial incentives for hospitals to prevent SSI, we aimed to compare hospital costs and earnings in colon surgery and coronary artery bypass grafting (CABG) patients, wit...

Background Certain cardiovascular diseases show diurnal variation, with a higher incidence of myocardial infarction in the morning. Conversely, aortic valve replacement surgery performed in the afternoon provided less myocardial injury and improved patient outcomes. We therefore examined a potential daytime varying effect on surgical site infection...

Background: Antimicrobial resistance data from surveillance networks are frequently do not accurately predict resistance patterns of urinary tract infections at the bedside. Ojective: To determine simple patient- and institution-related risk factors affecting antimicrobial resistance patterns of Escherichia coli urine isolates. Methods: From J...

To exploit the full potential of big routine data in healthcare and to efficiently communicate and collaborate with information technology specialists and data analysts, healthcare epidemiologists should have some knowledge of large-scale analysis techniques, particularly about machine learning. This review focuses on the broad area of machine lear...

Background: In an experimental setting, a simplified 3-step hand hygiene technique for applying alcohol-based hand rub was non-inferior in terms of reduction of bacterial counts as compared to the conventional WHO-6-step technique. We therefore compared compliance and microbiological efficacy between both hand hygiene techniques in routine clinica...

Background Healthcare-associated infections (HAIs) affect millions of patients, increasing morbidity and mortality. Pathogens of HAIs originate from both the patient's own flora and the environment, including multi-drug-resistant organisms. Aims To determine the bioburden on different types of high-touch surfaces, and to identify cultures to speci...

Background: Preliminary studies analyzing surrogate markers have suggested that operating room (OR) door openings may be a risk factor for surgical site infection (SSI). We therefore aimed to estimate the effect of OR door openings on SSI risk in patients receiving a cardiac surgery. Methods: This prospective observational study involved consecu...

We describe a scalable platform for research-oriented analyses of routine data in hospitals, which evolved from a state-of-the-art business intelligence architecture for enterprise resource planning. This platform involves an in-memory database management system for data modeling and analytics and a high-performance cluster for more computing-inten...

Objectives Management of bloodstream infections (“BSIs”) caused by Pseudomonas aeruginosa remains controversial as data supporting the use of definite combination treatment for severe P. aeruginosa infections remain conflicting. We aimed to determine differences in mortality between patients treated with definite combination therapy and monotherapy...

Based on a surgical site infection (SSI) cohort at an academic center, we showed a median potentially preventable loss per non-SSI case of $17,916 in colon surgery and of $34,741 in coronary artery bypass grafting.

Background Emergence of colistin resistance has been related to increased use in clinical settings, following global spread of carbapenem-resistant Gram-negative bacteria. Use of colistin in animal production may constitute a further source of spread of resistant strains to humans. We sought to determine risk factors for human colonisation or infec...

Background: Definitions and practices regarding use of contact precautions and isolation to prevent the spread of gram-positive and gram-negative multidrug-resistant organisms (MDRO) are not uniform. Methods: We conducted an on-site survey during the European Congress on Clinical Microbiology and Infectious Diseases 2014 to assess specific detai...

Objectives: Antibacterial chemoprophylaxis with fluoroquinolones (FQPx) has been commonly used in cancer patients with neutropenia, but its efficacy has been challenged by the emergence of fluoroquinolone resistance. Methods: The impact of FQPx on bloodstream infections (BSI) during neutropenia after high-dose chemotherapy for haematologic malig...

OBJECTIVE Worldwide, Mycobacterium chimaera infections have been linked to contaminated aerosols from heater-cooler units (HCUs) during open-heart surgery. These infections have mainly been associated with the 3T HCU (LivaNova, formerly Sorin). The reasons for this and the risk of transmission from other HCUs have not been systematically assessed....

Background: Observational studies have shown that dressings containing chlorhexidine gluconate (CHX) lower the incidence external ventricular drain (EVD) associated infections (EVDAI). This prospective, randomized controlled trial (RCT) studies the efficacy of CHX-containing dressings in reducing bacterial colonization, which represents an importa...

Rund 10 % aller nosokomialen Infektionen sind Septikämien mit positiven Blutkulturen, die zudem mit der höchsten Letalität einhergehen. Intravaskuläre Katheter sind häufig direkt oder indirekt ursächlich an der Sepsis beteiligt. Neue Erkenntnisse in Diagnostik, Therapie und Prävention beweisen, dass besonders Fort- und Weiterbildung die Schlüssel z...

Objectives: Little information is published on orthopaedic internal fixation-associated infections. We aimed to analyse time-dependent microbiology, treatment, and outcome. Methods: Over a ten-year period, all consecutive patients with internal fixation-associated infections at the University Hospital Basel were prospectively followed by acquiri...

Investigations of a worldwide epidemic of invasive Mycobacterium chimaera associated with heater–cooler devices in cardiac surgery have been hampered by low clinical awareness and challenging diagnoses. Using data from Switzerland, we estimated the burden of invasive M. chimaera to be 156–282 cases/year in 10 major cardiac valve replacement market...

Scope: Clostridium difficile infection (CDI) is the most important infective cause of healthcare-associated diarrhoea in high income countries and one of the most important healthcare-associated pathogens in both Europe and the United States. It is associated with high morbidity and mortality resulting in both societal and financial burden. A sign...

Defect Rates in Touchless Versus Mechanical Hand Hygiene Dispensers - Jan A. Roth, Bettina Batzer, Balthasar L. Hug, Andreas F. Widmer

We prospectively evaluated direct costs of contact precautions using on-site observation. Additional mean costs per patient day were calculated for extra materials used, increased workload, and one-off isolation activities. The cost of contact precautions was $158.90 (95% confidence interval, $124.90‒$192.80) per patient day. Infect Control Hosp Ep...

Background The extent of the occurrence of the plasmid-encoded colistin resistance genes mcr-1 and mcr-2 among humans is currently sparsely studied in Western Europe. Objectives To determine the occurrence of MCR-producing Enterobacteriaceae in fecal samples of healthy humans with high occupational exposure to food and primary care patients in Swit...

We describe an outbreak of Burkholderia stabilis associated with contaminated washing gloves, a commercially available Class I medical device. Triggered by an increase in Burkholderia cepacia complex (BCC) bacteremias and the detection of BCC in unopened packages of washing gloves, an ad hoc national outbreak committee comprising representatives of...

First Results of the Swiss National Surgical Site Infection Surveillance Program: Who Seeks Shall Find – ERRATUM - Volume 38 Issue 11

OBJECTIVES To evaluate host characteristics, mode of infection acquisition, and infection control procedures in patients with a positive respiratory syncytial virus (RSV) test result after the introduction of the GenXpert Influenza/RSV polymerase chain reaction (PCR) assay. DESIGN Retrospective cohort study. PATIENTS Adults with a positive PCR te...

Background: Staphylococcus aureus is the leading pathogen in surgical site infections (SSIs). Aim: To explore trends and risk factors associated with S. aureus SSI. Methods: We identified risk factors for monomicrobial S. aureus SSI from the Swiss multi-centre SSI surveillance system using multivariate logistic regression. Both in-hospital and...

Background Surgical antimicrobial prophylaxis (SAP) is standard of care in clean surgery involving implants and in clean-contaminated surgical procedures. Timing of application of the antibiotic remains a debate: WHO recently extended the time prior to incision from 60 to 120 minutes, while CDC considers the availabdata insufficient to provide evid...

Objectives: We determined the frequency of subsequent bloodstream infection >2 days after removal of a catheter with positive tip cultures. Methods: We conducted a nationwide, observational study on intravascular catheter (IVC) tip cultures in Switzerland from 2008 to 2015 using data from the Swiss Antibiotic Resistance Surveillance System (ANRE...