Heater-cooler units (HCUs) were recently identified as a source of Mycobacterium chimaera causing surgical site infections. We investigated transmission of this bacterium from HCUs to the surgical ...field by using a thermic anemometer and particle counter, videotape of an operating room equipped with an ultraclean laminar airflow ventilation system, and bacterial culture sedimentation plates in a nonventilated room. Smoke from the HCU reached the surgical field in 23 s by merging with ultraclean air. The HCU produced on average 5.2, 139, and 14.8 particles/min in the surgical field at positions Off, On/oriented toward, and On/oriented away, respectively. Culture plates were positive for M. chimaera <5 m from the HCU in the test room. These experiments confirm airborne transmission of M. chimaera aerosols from a contaminated HCU to an open surgical field despite ultraclean air ventilation. Efforts to mitigate infectious risks during surgery should consider contamination from water sources and airflow-generating devices.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
To determine the risk of SARS-CoV-2 transmission by aerosols, to provide evidence on the rational use of masks, and to discuss additional measures important for the protection of healthcare workers ...from COVID-19.
Literature review and expert opinion.
SARS-CoV-2, the pathogen causing COVID-19, is considered to be transmitted via droplets rather than aerosols, but droplets with strong directional airflow support may spread further than 2 m. High rates of COVID-19 infections in healthcare-workers (HCWs) have been reported from several countries. Respirators such as filtering face piece (FFP) 2 masks were designed to protect HCWs, while surgical masks were originally intended to protect patients (e.g., during surgery). Nevertheless, high quality standard surgical masks (type II/IIR according to European Norm EN 14683) appear to be as effective as FFP2 masks in preventing droplet-associated viral infections of HCWs as reported from influenza or SARS. So far, no head-to-head trials with these masks have been published for COVID-19. Neither mask type completely prevents transmission, which may be due to inappropriate handling and alternative transmission pathways. Therefore, compliance with a bundle of infection control measures including thorough hand hygiene is key. During high-risk procedures, both droplets and aerosols may be produced, reason why respirators are indicated for these interventions.
Abstract
Changing microorganism distributions and decreasing antibiotic susceptibility over the duration of hospitalization have been described for the colonization or infection of selected organ ...systems. Few data are available on bacteremias in the intensive care unit (ICU) setting. We conducted a nationwide study on bloodstream infection (BSI) using data from the Swiss Centre for Antibiotic Resistance (ANRESIS). We analyzed data on BSI detected in the ICU from hospitals that sent information on a regular basis during the entire study period (2008–2017). We described specific trends of pathogen distribution and resistance during hospitalization duration. We included 6505 ICU- BSI isolates from 35 Swiss hospitals. We observed 2587 possible skin contaminants, 3788 bacteremias and 130 fungemias. The most common microorganism was
Escherichia coli
(23.2%, 910), followed by
Staphylococcus aureus
(18.7%, 734) and enterococci (13.1%, 515).
Enterococcus
spp (p < 0.0001) and
Candida
spp (p < 0.0001) increased in proportion, whereas
E. coli
(p < 0.0001) and
S. aureus
(p < 0.0001) proportions decreased during hospitalization. Resistances against first- and second-line antibiotics increased linearly during hospitalization. Pathogen distribution and antimicrobial resistance in ICU-BSI depends on the duration of the hospitalization. The proportion of enterococcal BSI, candidemia and resistant microorganisms against first- and second-line antibiotics increased during hospitalization.
Ventilator-associated pneumonia (VAP) is a frequent complication of mechanical ventilation and is associated with substantial morbidity and mortality. Accurate diagnosis of VAP relies in part on ...subjective diagnostic criteria. Surveillance according to ventilator-associated event (VAE) criteria may allow quick and objective benchmarking. Our objective was to create an automated surveillance tool for VAE tiers I and II on a large data collection, evaluate its diagnostic accuracy and retrospectively determine the yearly baseline VAE incidence. We included all consecutive intensive care unit admissions of patients with mechanical ventilation at Bern University Hospital, a tertiary referral center, from January 2008 to July 2016. Data was automatically extracted from the patient data management system and automatically processed. We created and implemented an application able to automatically analyze respiratory and relevant medication data according to the Centers for Disease Control protocol for VAE-surveillance. In a subset of patients, we compared the accuracy of automated VAE surveillance according to CDC criteria to a gold standard (a composite of automated and manual evaluation with mediation for discrepancies) and evaluated the evolution of the baseline incidence. The study included 22'442 ventilated admissions with a total of 37'221 ventilator days. 592 ventilator-associated events (tier I) occurred; of these 194 (34%) were of potentially infectious origin (tier II). In our validation sample, automated surveillance had a sensitivity of 98% and specificity of 100% in detecting VAE compared to the gold standard. The yearly VAE incidence rate ranged from 10.1-22.1 per 1000 device days and trend showed a decrease in the yearly incidence rate ratio of 0.96 (95% CI, 0.93-1.00, p = 0.03). This study demonstrated that automated VAE detection is feasible, accurate and reliable and may be applied on a large, retrospective sample and provided insight into long-term institutional VAE incidences. The surveillance tool can be extended to other centres and provides VAE incidences for performing quality control and intervention studies.
Arenaviruses such as Lassa virus (LASV) can cause severe hemorrhagic fever in humans. As a major impediment to vaccine development, delayed and weak neutralizing antibody (nAb) responses represent a ...unifying characteristic of both natural infection and all vaccine candidates tested to date. To investigate the mechanisms underlying arenavirus nAb evasion we engineered several arenavirus envelope-chimeric viruses and glycan-deficient variants thereof. We performed neutralization tests with sera from experimentally infected mice and from LASV-convalescent human patients. NAb response kinetics in mice correlated inversely with the N-linked glycan density in the arenavirus envelope protein's globular head. Additionally and most intriguingly, infection with fully glycosylated viruses elicited antibodies, which neutralized predominantly their glycan-deficient variants, both in mice and humans. Binding studies with monoclonal antibodies indicated that envelope glycans reduced nAb on-rate, occupancy and thereby counteracted virus neutralization. In infected mice, the envelope glycan shield promoted protracted viral infection by preventing its timely elimination by the ensuing antibody response. Thus, arenavirus envelope glycosylation impairs the protective efficacy rather than the induction of nAbs, and thereby prevents efficient antibody-mediated virus control. This immune evasion mechanism imposes limitations on antibody-based vaccination and convalescent serum therapy.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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 countries.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The overall burden of healthcare-associated infections (HAIs) remains high, even in high-income countries. However, the current burden of HAI in Switzerland is unknown. Prevalence surveys have a long ...tradition in the field of infection prevention and control for measuring both HAI and antimicrobial use. The objective of this survey was to test the point prevalence survey (PPS) methodology of the European Centre for Disease Prevention and Control (ECDC) in acute-care hospitals in Switzerland.
Two tertiary care hospitals and one secondary care hospital in central and western Switzerland participated in the survey. Patients from all wards except for emergency departments and psychiatric wards were included. Data were collected on a single day for every ward with a maximum time frame of 2 weeks for completing data collection. Methodology and definitions were based on the most recent ECDC PPS protocol.
Data on a total of 2421 patients were analysed. One hundred thirty-six patients had 153 HAIs, corresponding to a prevalence of 5.6% (95% confidence interval CI 4.7-6.5%). Rapidly fatal McCabe score, hospitalisation in the intensive care unit (ICU), and having a medical device in place were independent risk factors for HAI. Lower respiratory tract infection was the most frequent HAI type (24.8%), followed by surgical site infection (22.2%), bloodstream infection (17.0%) and urinary tract infection (13.7%). The highest HAI prevalence (26.2%) was observed in the ICU. In total, 60.8% of all HAIs were microbiologically confirmed. The most common microorganism was Escherichia coli (21.1%). Six hundred sixty-nine patients (27.6%, 95% CI 25.9-29.4%) received 893 antimicrobials for 705 indications. Community-acquired infections (39.0%) were the most common indication for antimicrobial use and amoxicillin-clavulanate was the most commonly prescribed antimicrobial (18.4%).
HAI prevalence and antimicrobial use in this survey were similar to findings of the past ECDC PPS. The ECDC methodology proved applicable to Swiss acute-care hospitals.
Invasive Mycobacterium chimaera infections after open-heart surgery have been reported internationally. These devastating infections result from aerosols generated by contaminated heater-cooler units ...used with extracorporeal circulation during surgery. Despite intensified cleaning and disinfection, surveillance samples from factory-new units acquired during 2014 grew nontuberculous mycobacteria after a median of 174 days.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Candida auris, a globally emerging pathogen, has been repeatedly introduced into European healthcare settings, leading to large and long-lasting nosocomial outbreaks. The pathogen has already been ...isolated in Switzerland, requiring clinicians and microbiologists to become alert. This is the first comprehensive guidance document on prevention and control of C. auris in Swiss acute care hospitals. It brings to light the most recent evidence from published original articles and reviews. We emphasise the importance of quickly identifying this yeast by means of screening in order to prevent an outbreak that could be difficult to contain. Key containment strategies include reinforcing early detection, hand hygiene, application of strict contact precautions for colonised and infected patients, and thorough specific environmental cleaning and disinfection.
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