Association of a coronavirus disease 2019 (COVID-19) vaccine booster with control of a COVID-19 outbreak in a long-term care facility in Switzerland, November to December 2021.

Coronavirus disease 2019 (COVID-19) outbreaks in long-term care facilities are often correlated with high case fatality rates. We describe the association of administration of an mRNA booster with the control of an outbreak. Our findings highlight the possibility of vaccine booster early in an outbreak as a promising method to mitigate the spread of infection.

Association between the introduction of a national targeted intervention program and the incidence of surgical site infections in Swiss acute care hospitals.

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 participating hospitals. METHODS: Prospective multicenter pre- and postintervention study conducted in eight Swiss acute care hospitals between 2013 and 2020. All consecutive patients > 18 years undergoing cardiac, colon, or hip/knee replacement surgery were included. The follow-up period was 30 days and one year for implant-related surgery. Patients with at least one follow-up were included. The intervention was to optimize three elements of preoperative management: (i) hair removal; (ii) skin disinfection; and (iii) perioperative antimicrobial prophylaxis. We compared SSI incidence rates (main outcome measure) pre- and postintervention (three years each) adjusted for potential confounders. Poisson generalized linear mixed models fitted to quarter-yearly confirmed SSIs and adjusted for baseline differences between hospitals and procedures. Adherence was routinely monitored through on-site visits. RESULTS: A total of 10 151 patients were included, with a similar median age pre- and postintervention (69.6 and IQR 60.9, 76.8 years, vs 69.5 and IQR 60.4, 76.8 years, respectively; P = 0.55) and similar proportions of females (44.8% vs. 46.1%, respectively; P = 0.227). Preintervention, 309 SSIs occurred in 5 489 patients (5.6%), compared to 226 infections in 4 662 cases (4.8%, P = 0.09) postintervention. The adjusted incidence rate ratio (aIRR) for overall SSI after intervention implementation was 0.81 (95% CI, 0.68 to 0.96, P = 0.02). For cardiac surgery (n = 2 927), the aIRR of SSI was 0.48 (95% CI, 0.32 to 0.72, P < 0.001). For hip/knee replacement surgery (n = 4 522), the aIRR was 0.88 (95% CI, 0.52 to 1.48, P = 0.63), and for colon surgery (n = 2 702), the aIRR was 0.92 (95% CI, 0.75 to 1.14, P = 0.49). CONCLUSIONS: The SSI intervention bundle was associated with a statistically significant decrease in SSI cases. A significant association was observed for cardiac surgery. Adding a specific intervention program can add value compared to routine surveillance only. Further prevention modules might be necessary for colon and orthopedic surgery.

[Surgical site infection after lower limb arterial reconstruction: can we improve prevention?] / Infections postchirurgie artérielle des membres inférieurs : peut-on mieux faire?

Infections associated with arterial reconstructions of the lower limbs are associated with high morbidity. This article reviews the risk factors for infection associated with this surgery and the preventive measures. These include smoking cessation and glycemic control preoperatively; avoiding unnecessary exposure to antibiotics or corticosteroids; optimal peripheral wound care; rigorous antisepsis and antibiotic prophylaxis in the operating theatre ; and finally, meticulous post-operative wound monitoring. The benefit of Staphylococcus aureus decolonization in vascular surgery is less clearly established than in cardiac and thoracic surgery, but it is still recommended in cases of implant placement or where there is a high risk of S. aureus infection, depending on the planned approach and type of surgery.

Les infections associées aux reconstructions artérielles des membres inférieurs sont grevées d'une morbidité élevée. Cet article revoit les facteurs de risque d'infection associés à cette chirurgie et les mesures de prévention. Ces dernières incluent l'arrêt du tabac et le contrôle glycémique en préopératoire ; l'absence d'exposition inutile aux antibiotiques ou aux corticostéroïdes ; les soins de plaies périphériques optimaux ; une antisepsie et une antibioprophylaxie au bloc opératoire rigoureuses et, finalement, un suivi de plaie postopératoire minutieux. Le bénéfice de la décolonisation à Staphylococcus aureus dans le cadre de la chirurgie vasculaire est moins clairement établi qu'en chirurgies cardiaque et thoracique, mais celle-ci reste recommandée en cas de mise en place d'implant ou de risque élevé d'infection à S. aureus, selon la voie d'abord et le type de chirurgie prévue.

Treatment effect of remdesivir on the mortality of hospitalised COVID-19 patients in Switzerland across different patient groups: a tree-based model analysis.

AIMS OF THE STUDY: Remdesivir has shown benefits against COVID-19. However, it remains unclear whether, to what extent, and among whom remdesivir can reduce COVID-19-related mortality. We explored whether the treatment response to remdesivir differed by patient characteristics. METHODS: We analysed data collected from a hospital surveillance study conducted in 21 referral hospitals in Switzerland between 2020 and 2022. We applied model-based recursive partitioning to group patients by the association between treatment levels and mortality. We included either treatment (levels: none, remdesivir within 7 days of symptom onset, remdesivir after 7 days, or another treatment), age and sex, or treatment only as regression variables. Candidate partitioning variables included a range of risk factors and comorbidities (and age and sex unless included in regression). We repeated the analyses using local centring to correct the results for the propensity to receive treatment. RESULTS: Overall (n = 21,790 patients), remdesivir within 7 days was associated with increased mortality (adjusted hazard ratios 1.28-1.54 versus no treatment). The CURB-65 score caused the most instability in the regression parameters of the model. When adjusted for age and sex, patients receiving remdesivir within 7 days of onset had higher mortality than those not treated in all identified eight patient groups. When age and sex were included as partitioning variables instead, the number of groups increased to 19-20; in five to six of those branches, mortality was lower among patients who received early remdesivir. Factors determining the groups where remdesivir was potentially beneficial included the presence of oncological comorbidities, male sex, and high age. CONCLUSIONS: Some subgroups of patients, such as individuals with oncological comorbidities or elderly males, may benefit from remdesivir.

Timing of Cefuroxime Surgical Antimicrobial Prophylaxis and Its Association With Surgical Site Infections.

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 associated with the occurrence of surgical site infections (SSI). Design, Setting, and Participants: This cohort study included adult patients who underwent 1 of 11 major surgical procedures with cefuroxime SAP, documented by the Swissnoso SSI surveillance system between January 2009 and December 2020 at 158 Swiss hospitals. Data were analyzed from January 2021 to April 2023. Exposures: Timing of cefuroxime SAP administration before incision was divided into 3 groups: 61 to 120 minutes before incision, 31 to 60 minutes before incision, and 0 to 30 minutes before incision. In addition, a subgroup analysis was performed with time windows of 30 to 55 minutes and 10 to 25 minutes as a surrogate marker for administration in the preoperating room vs in the operating room, respectively. The timing of SAP administration was defined as the start of the infusion obtained from the anesthesia protocol. Main Outcomes and Measures: Occurrence of SSI according to Centers for Disease Control and Prevention definitions. Mixed-effects logistic regression models adjusted for institutional, patient, and perioperative variables were applied. Results: Of 538 967 surveilled patients, 222 439 (104 047 men [46.8%]; median [IQR] age, 65.7 [53.9-74.2] years), fulfilled inclusion criteria. SSI was identified in 5355 patients (2.4%). Cefuroxime SAP was administered 61 to 120 minutes prior to incision in 27 207 patients (12.2%), 31 to 60 minutes prior to incision in 118 004 patients (53.1%), and 0 to 30 minutes prior to incision in 77 228 patients (34.7%). SAP administration at 0 to 30 minutes was significantly associated with a lower SSI rate (adjusted odds ratio [aOR], 0.85; 95% CI, 0.78-0.93; P < .001), as was SAP administration 31 to 60 minutes prior to incision (aOR, 0.91; 95% CI, 0.84-0.98; P = .01) compared with administration 61 to 120 minutes prior to incision. Administration 10 to 25 minutes prior to incision in 45 448 patients (20.4%) was significantly associated with a lower SSI rate (aOR, 0.89; 95% CI, 0.82-0.97; P = .009) vs administration within 30 to 55 minutes prior to incision in 117 348 patients (52.8%). Conclusions and Relevance: In this cohort study, administration of cefuroxime SAP closer to the incision time was associated with significantly lower odds of SSI, suggesting that cefuroxime SAP should be administrated within 60 minutes prior to incision, and ideally within 10 to 25 minutes.

Hospital Outcomes of Community-Acquired SARS-CoV-2 Omicron Variant Infection Compared With Influenza Infection in Switzerland.

Importance: With the ongoing COVID-19 pandemic, it is crucial to assess the current burden of disease of community-acquired SARS-CoV-2 Omicron variant in hospitalized patients to tailor appropriate public health policies. Comparisons with better-known seasonal influenza infections may facilitate such decisions. Objective: To compare the in-hospital outcomes of patients hospitalized with the SARS-CoV-2 Omicron variant with patients with influenza. Design, Setting, and Participants: This cohort study was based on a national COVID-19 and influenza registry. Hospitalized patients aged 18 years and older with community-acquired SARS-CoV-2 Omicron variant infection who were admitted between January 15 and March 15, 2022 (when B.1.1.529 Omicron predominance was >95%), and hospitalized patients with influenza A or B infection from January 1, 2018, to March 15, 2022, where included. Patients without a study outcome by August 30, 2022, were censored. The study was conducted at 15 hospitals in Switzerland. Exposures: Community-acquired SARS-CoV-2 Omicron variant vs community-acquired seasonal influenza A or B. Main Outcomes and Measures: Primary and secondary outcomes were defined as in-hospital mortality and admission to the intensive care unit (ICU) for patients with the SARS-CoV-2 Omicron variant or influenza. Cox regression (cause-specific and Fine-Gray subdistribution hazard models) was used to account for time-dependency and competing events, with inverse probability weighting to adjust for confounders with right-censoring at day 30. Results: Of 5212 patients included from 15 hospitals, 3066 (58.8%) had SARS-CoV-2 Omicron variant infection in 14 centers and 2146 patients (41.2%) had influenza A or B in 14 centers. Of patients with the SARS-CoV-2 Omicron variant, 1485 (48.4%) were female, while 1113 patients with influenza (51.9%) were female (P = .02). Patients with the SARS-CoV-2 Omicron variant were younger (median [IQR] age, 71 [53-82] years) than those with influenza (median [IQR] age, 74 [59-83] years; P < .001). Overall, 214 patients with the SARS-CoV-2 Omicron variant (7.0%) died during hospitalization vs 95 patients with influenza (4.4%; P < .001). The final adjusted subdistribution hazard ratio (sdHR) for in-hospital death for SARS-CoV-2 Omicron variant vs influenza was 1.54 (95% CI, 1.18-2.01; P = .002). Overall, 250 patients with the SARS-CoV-2 Omicron variant (8.6%) vs 169 patients with influenza (8.3%) were admitted to the ICU (P = .79). After adjustment, the SARS-CoV-2 Omicron variant was not significantly associated with increased ICU admission vs influenza (sdHR, 1.08; 95% CI, 0.88-1.32; P = .50). Conclusions and Relevance: The data from this prospective, multicenter cohort study suggest a significantly increased risk of in-hospital mortality for patients with the SARS-CoV-2 Omicron variant vs those with influenza, while ICU admission rates were similar.

The impact of public health interventions on the future prevalence of ESBL-producing Klebsiella pneumoniae: a population based mathematical modelling study.

BACKGROUND: Future prevalence of colonization with extended-spectrum betalactamase (ESBL-) producing K. pneumoniae in humans and the potential of public health interventions against the spread of these resistant bacteria remain uncertain. METHODS: Based on antimicrobial consumption and susceptibility data recorded during > 13 years in a Swiss region, we developed a mathematical model to assess the comparative effect of different interventions on the prevalence of colonization. RESULTS: Simulated prevalence stabilized in the near future when rates of antimicrobial consumption and in-hospital transmission were assumed to remain stable (2025 prevalence: 6.8% (95CI%:5.4-8.8%) in hospitals, 3.5% (2.5-5.0%) in the community versus 6.1% (5.0-7.5%) and 3.2% (2.3-4.2%) in 2019, respectively). When overall antimicrobial consumption was set to decrease by 50%, 2025 prevalence declined by 75% in hospitals and by 64% in the community. A 50% decline in in-hospital transmission rate led to a reduction in 2025 prevalence of 31% in hospitals and no reduction in the community. The best model fit estimated that 49% (6-100%) of observed colonizations could be attributable to sources other than human-to-human transmission within the geographical setting. CONCLUSIONS: Projections suggests that overall antimicrobial consumption will be, by far, the most powerful driver of prevalence and that a large fraction of colonizations could be attributed to non-local transmissions.

Meticillin-resistant Staphylococcus aureus Contact Screening Strategy in a Low Prevalence Setting; a Nested Case-Control Study.

Background: The optimal screening strategy in hospitals to identify secondary cases after contact with a meticillin-resistant Staphylococcus aureus (MRSA) index patient in a low prevalence setting is not well defined. We aimed at identifying factors associated with documented MRSA transmissions. Method: Single center, retrospective, nested case-control study. We evaluated the screening strategy in our 950 bed tertiary care hospital from 2008 - 2014. Room and ward contacts of MRSA index patients present at time of MRSA identification were screened. We compared characteristics of Staphylococcus aureus Protein A (spa)-type matched contact patients (cases) to negative or spa-type mismatched contact patients (controls). Results: Among 270,000 inpatients from 2008 - 2014, 215 MRSA screenings yielded 3013 contact patients, and 6 (0.2%) spa-type matched pairs. We included 225 controls for the nested case-control study. The contact type for the cases was more frequently "same room" and less frequently "same ward" compared with the controls (P = 0.001). Also, exposure time was longer for cases (median of 6 days [IQR 3-9]) than for controls (1 day [0-3], P=0.016). Conclusion: The extensive MRSA screening strategy revealed only few index/contact matches based on spa-typing. Prolonged exposure time and a shared room were significantly associated with MRSA transmission. A targeted screening strategy may be more useful in a low prevalence setting than screening entire wards.

Agrobacterium species bacteraemia, Switzerland, 2008 to 2019: a molecular epidemiological study.

BACKGROUND: Agrobacterium spp. are infrequent agents of bloodstream infections linked to healthcare-associated outbreaks. However, it is unclear if outbreaks also occur across larger geographic areas. Triggered by two local clusters from putative point sources, our aim was to detect potential additional clusters in Switzerland. METHODS: We performed a nationwide descriptive study of cases in Switzerland based on a prospective surveillance system (Swiss Centre for Antibiotic Resistance, anresis.ch), from 2008 to 2019. We identified patients with Agrobacterium spp. isolated from blood cultures and used a survey to collect clinical-epidemiological information and susceptibility testing results. We performed whole genome sequencing (WGS) of available clinical isolates and determined their relatedness by single nucleotide polymorphism (SNP) variant calling analysis. RESULTS: We identified a total of 36 cases of Agrobacterium spp. from blood samples over 10 years. Beyond previously known local clusters, no new ones were identified. WGS-based typing was performed on 22 available isolates and showed no clonal relationships between newly identified isolates or to those from the known clusters, with all isolates outside these clusters being at least 50 SNPs apart. CONCLUSION AND RELEVANCE: Agrobacterium spp. bacteraemia is infrequently detected and, given that it may be healthcare-associated and stem from a point source, occurrence of multiple episodes should entail an outbreak investigation. With the help of the national antimicrobial resistance surveillance system we identified multiple clinical cases of this rare pathogen but found no evidence by WGS that suggested a nation-wide outbreak.

Antibody bivalency improves antiviral efficacy by inhibiting virion release independently of Fc gamma receptors.

Across the animal kingdom, multivalency discriminates antibodies from all other immunoglobulin superfamily members. The evolutionary forces conserving multivalency above other structural hallmarks of antibodies remain, however, incompletely defined. Here, we engineer monovalent either Fc-competent or -deficient antibody formats to investigate mechanisms of protection of neutralizing antibodies (nAbs) and non-neutralizing antibodies (nnAbs) in virus-infected mice. Antibody bivalency enables the tethering of virions to the infected cell surface, inhibits the release of virions in cell culture, and suppresses viral loads in vivo independently of Fc gamma receptor (FcγR) interactions. In return, monovalent antibody formats either do not inhibit virion release and fail to protect in vivo or their protective efficacy is largely FcγR dependent. Protection in mice correlates with virus-release-inhibiting activity of nAb and nnAb rather than with their neutralizing capacity. These observations provide mechanistic insights into the evolutionary conservation of antibody bivalency and help refining correlates of nnAb protection for vaccine development.

Providing care to patients in contact isolation: is the systematic use of gloves still indicated?

This article reviews the available evidence on the effectiveness of gloves in preventing infection during care provided to patients under contact precautions, and analyses the risks and benefits of their systematic use. Although hand hygiene with alcohol-based handrub was shown to be effective in preventing nosocomial infections, many publications put the effectiveness and usefulness of gloves into perspective. Instead, literature and various unpublished experiences point towards reduced hand hygiene compliance and increased risk of spreading pathogens with routine glove use. Therefore, hospitals should emphasise hand hygiene in their healthcare staff and, instead of the routine use of gloves when caring for patients under contact precautions, limit their use to the indications of standard precautions, i.e., mainly for contact with body fluids. Wide and easy access to alcohol-based handrub and continual teaching are essential. If such conditions are met and adherence to hand hygiene is excellent and regularly assessed, the routine use of gloves for patients under contact precautions seems no longer indicated.

High adherence to national IPC guidelines as key to sustainable VRE control in Swiss hospitals: a cross-sectional survey.

BACKGROUND: Vancomycin resistant enterococci (VRE) are on the rise in many European hospitals. In 2018, Switzerland experienced its largest nosocomial VRE outbreak. The national center for infection prevention (Swissnoso) elaborated recommendations for controlling this outbreak and published guidelines to prevent epidemic and endemic VRE spread. The primary goal of this study was to evaluate adherence to this new guideline and its potential impact on the VRE epidemiology in Swiss acute care hospitals. METHODS: In March 2020, Swissnoso distributed a survey among all Swiss acute care hospitals. The level of adherence as well as changes of infection prevention and control (IPC) strategies in the years 2018 and 2019 after publication of the national guidelines were asked along with an inventory on VRE surveillance and outbreaks. RESULTS: Data of 97/146 (66%) participants were available, representing 81.6% of all acute care beds operated in Switzerland in 2019. The vast majority-72/81 (88%) responding hospitals-have entirely or largely adopted our new national guideline. 38/51 (74.5%) hospitals which experienced VRE cases were significantly more likely to have changed their IPC strategies than those 19/38 (50%) hospitals without VRE cases p = 0.017). The new IPC guidelines included (1) introduction of targeted admission screening in 89.5%, (2) screening of close contacts of VRE cases in 56%, and (3) contact precaution for suspected VRE cases 58% of these hospitals. 52 (54%) hospitals reported 569 new VRE cases in 2018 including 14 bacteremia, and 472 new cases in 2019 with 10 bacteremia. The ten largest outbreaks encountered between 2018 and 2019 included 671 VRE cases, of which most (93.4%) consisted of colonization events, 29 (4.3%) infections and 15 (2.2%) bacteremia. CONCLUSION: Wide adoption of this VRE control guideline seemed to have a positive effect on VRE containment in Swiss acute care hospitals over two years, even if its long-term impact on the VRE epidemiology remains to be evaluated. Broad dissemination and strict implementation of a uniform national guideline may therefore serve as model for other countries to fight VRE epidemics on a national level.

Hospital outcomes of community-acquired COVID-19 versus influenza: Insights from the Swiss hospital-based surveillance of influenza and COVID-19.

BackgroundSince the onset of the COVID-19 pandemic, the disease has frequently been compared with seasonal influenza, but this comparison is based on little empirical data.AimThis study compares in-hospital outcomes for patients with community-acquired COVID-19 and patients with community-acquired influenza in Switzerland.MethodsThis retrospective multi-centre cohort study includes patients > 18 years admitted for COVID-19 or influenza A/B infection determined by RT-PCR. Primary and secondary outcomes were in-hospital mortality and intensive care unit (ICU) admission for patients with COVID-19 or influenza. We used Cox regression (cause-specific and Fine-Gray subdistribution hazard models) to account for time-dependency and competing events with inverse probability weighting to adjust for confounders.ResultsIn 2020, 2,843 patients with COVID-19 from 14 centres were included. Between 2018 and 2020, 1,381 patients with influenza from seven centres were included; 1,722 (61%) of the patients with COVID-19 and 666 (48%) of the patients with influenza were male (p < 0.001). The patients with COVID-19 were younger (median 67 years; interquartile range (IQR): 54-78) than the patients with influenza (median 74 years; IQR: 61-84) (p < 0.001). A larger percentage of patients with COVID-19 (12.8%) than patients with influenza (4.4%) died in hospital (p < 0.001). The final adjusted subdistribution hazard ratio for mortality was 3.01 (95% CI: 2.22-4.09; p < 0.001) for COVID-19 compared with influenza and 2.44 (95% CI: 2.00-3.00, p < 0.001) for ICU admission.ConclusionCommunity-acquired COVID-19 was associated with worse outcomes compared with community-acquired influenza, as the hazards of ICU admission and in-hospital death were about two-fold to three-fold higher.

Droplet precautions on-site (DroPS) during the influenza season 2018/2019: a possible alternative to single room isolation for respiratory viral infections.

BACKGROUND: The guideline-driven and widely implemented single room isolation strategy for respiratory viral infections (RVI) such as influenza or respiratory syncytial virus (RSV) can lead to a shortage of available hospital beds. We discuss our experience with the introduction of droplet precautions on-site (DroPS) as a possible alternative. METHODS: During the 2018/19 influenza season we introduced DroPS on several wards of a single tertiary care center, while other wards maintained the traditional single room isolation strategy. On a daily basis, we evaluated patients for the development of respiratory symptoms and screened those with a clinical diagnosis of hospital-acquired respiratory viral infection (HARVI) for influenza/RSV by molecular rapid test. If negative, it was followed by a multiplex respiratory virus PCR. We report the concept of DroPS, the feasibility of the strategy and the rate of microbiologically confirmed HARVI with influenza or RSV infection on the DroPS wards compared to wards using the traditional single room isolation strategy. RESULTS: We evaluated all hospitalised patients at risk for a HARVI, 741 (72%) on the DroPS wards and 293 (28%) on the regular wards. The hospital-acquired infection rate with influenza or RSV was 2/741 (0.3%; 1× influenza A, 1× RSV) on the DroPS wards and 2/293 (0.7%; 2× influenza A) on the regular wards. CONCLUSIONS: Droplet precautions on-site (DroPS) may be a simple and potentially resource-saving alternative to the standard single room isolation strategy for respiratory viral infections. Further studies in a larger clinical context are needed to document its safety.

Nosocomial outbreak of vancomycin-resistant Enterococcus faecium (VRE) ST796, Switzerland, 2017 to 2020.

A large clonal outbreak caused by vancomycin-resistant Enterococcus faecium (VRE) affected the Bern University Hospital group from the end of December 2017 until July 2020. We describe the characteristics of the outbreak and the bundle of infection prevention and control (IPC) measures implemented. The outbreak was first recognised when two concomitant cases of VRE bloodstream infection were identified on the oncology ward. During 32 months, 518 patients in the 1,300-bed hospital group were identified as vanB VRE carriers. Eighteen (3.5%) patients developed an invasive infection, of whom seven had bacteraemia. In 2018, a subset of 328 isolates were analysed by whole genome sequencing, 312 of which were identified as sequence type (ST) 796. The initial IPC measures were implemented with a focus on the affected wards. However, in June 2018, ST796 caused another increase in cases, and the management strategy was intensified and escalated to a hospital-wide level. The clinical impact of this large nosocomial VRE outbreak with the emergent clone ST796 was modest. A hospital-wide approach with a multimodal IPC bundle was successful against this highly transmissible strain.

Association Between Antimicrobial Prophylaxis With Double-Dose Cefuroxime and Surgical Site Infections in Patients Weighing 80 kg or More.

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 patients weighing at least 80 kg. Design, Setting, and Participants: This cohort study included adult patients (>18 years) weighing at least 80 kg who underwent 9 major surgical procedures with a cefuroxime SAP administration from the Swissnoso SSI surveillance system between January 2015 and December 2019 at 142 Swiss hospitals. The follow-up was 30 days for all surgical procedures and 1 year for implant-related operations. Exposures: Cefuroxime SAP dose (1.5 vs 3.0 g). Main Outcomes and Measures: Overall SSI. A mixed-effects logistic regression adjusted for institutional, epidemiological, and perioperative variables was applied. Results were stratified by weight categories as well as by wound contamination classes. Results: Of 41 076 eligible patients, 37 640 were included, with 22 625 (60.1%) men and a median (IQR) age of 61.9 (49.9-71.1) years. The outcome SSI was met by 1203 patients (3.2%). Double-dose cefuroxime was administered to 13 246 patients (35.2%) and was not significantly associated with a lower SSI rate (adjusted odds ratio [aOR], 0.89; 95% CI, 0.78-1.02; P = .10). After stratification by weight category, double-dose SAP vs single-dose SAP was associated with lower SSI rates among 16 605 patients weighing at least 80 to less than 90 kg (aOR, 0.76; 95% CI, 0.61-0.97; P = .02) but not in the other weight categories (≥90 to <100 kg, 10 342 patients: aOR, 1.12; 95% CI, 0.87-1.47; P = .37; ≥100 to <120 kg, 8099 patients: aOR, 0.99; 95% CI, 0.76-1.30; P = .96; ≥120 kg, 2594 patients: aOR, 0.65; 95% CI, 0.42-1.04; P = .06). After stratification by contamination class, double-dose SAP was associated with lower SSI rates among 1946 patients with contaminated wounds (aOR, 0.49; 95% CI, 0.30-0.84; P = .008) but not those with clean wounds (25 680 patients; aOR, 0.92; 95% CI, 0.76-1.12; P = .44) or clean-contaminated wounds (10 014 patients; aOR, 0.90; 95% CI, 0.73-1.12; P = .37) compared with a single dose. Conclusions and Relevance: In this study, double-dose SAP with cefuroxime for patients weighing at least 80 kg was not consistently associated with a lower SSI rate.

Evolution of COVID-19 mortality over time: results from the Swiss hospital surveillance system (CH-SUR).

BACKGROUND: When the periods of time during and after the first wave of the ongoing SARS-CoV-2/COVID-19 pandemic in Europe are compared, the associated COVID-19 mortality seems to have decreased substantially. Various factors could explain this trend, including changes in demographic characteristics of infected persons and the improvement of case management. To date, no study has been performed to investigate the evolution of COVID-19 in-hospital mortality in Switzerland, while also accounting for risk factors. METHODS: We investigated the trends in COVID-19-related mortality (in-hospital and in-intermediate/intensive-care) over time in Switzerland, from February 2020 to June 2021, comparing in particular the first and the second wave. We used data from the COVID-19 Hospital-based Surveillance (CH-SUR) database. We performed survival analyses adjusting for well-known risk factors of COVID-19 mortality (age, sex and comorbidities) and accounting for competing risk. RESULTS: Our analysis included 16,984 patients recorded in CH-SUR, with 2201 reported deaths due to COVID-19 (13.0%). We found that overall in-hospital mortality was lower during the second wave of COVID-19 than in the first wave (hazard ratio [HR] 0.70, 95% confidence interval [CI] 0.63- 0.78; p <0.001), a decrease apparently not explained by changes in demographic characteristics of patients. In contrast, mortality in intermediate and intensive care significantly increased in the second wave compared with the first wave (HR 1.25, 95% CI 1.05-1.49; p = 0.029), with significant changes in the course of hospitalisation between the first and the second wave. CONCLUSION: We found that, in Switzerland, COVID-19 mortality decreased among hospitalised persons, whereas it increased among patients admitted to intermediate or intensive care, when comparing the second wave to the first wave. We put our findings in perspective with changes over time in case management, treatment strategy, hospital burden and non-pharmaceutical interventions. Further analyses of the potential effect of virus variants and of vaccination on mortality would be crucial to have a complete overview of COVID-19 mortality trends throughout the different phases of the pandemic.

An automated retrospective VAE-surveillance tool for future quality improvement studies.

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.

The effect of the COVID-19 pandemic on the epidemiology of positive blood cultures in Swiss intensive care units: a nationwide surveillance study.

BACKGROUND: Evidence about the impact of the pandemic of COVID-19 on the incidence rates of blood cultures contaminations and bloodstream infections in intensive care units (ICUs) remains scant. The objective of this study was to investigate the nationwide epidemiology of positive blood cultures drawn in ICUs during the first two pandemic waves of COVID-19 in Switzerland. METHODS: We analyzed data on positive blood cultures among ICU patients, prospectively collected through a nationwide surveillance system (ANRESIS), from March 30, 2020, to May 31, 2021, a 14-month timeframe that included a first wave of COVID-19, which affected the French and Italian-speaking regions, an interim period (summer 2020) and a second wave that affected the entire country. We used the number of ICU patient-days provided by the Swiss Federal Office of Public Health as denominator to calculate incidence rates of blood culture contaminations and bloodstream infections (ICU-BSI). Incidence rate ratios comparing the interim period with the second wave were determined by segmented Poisson regression models. RESULTS: A total of 1099 blood culture contaminations and 1616 ICU-BSIs were identified in 52 ICUs during the study. Overall, more episodes of blood culture contaminations and ICU-BSI were observed during the pandemic waves, compared to the interim period. The proportions of blood culture contaminations and ICU-BSI were positively associated with the ICU occupancy rate, which was higher during the COVID-19 waves. During the more representative second wave (versus interim period), we observed an increased incidence of blood culture contaminations (IRR 1.57, 95% CI 1.16-2.12) and ICU-BSI (IRR 1.20, 95% CI 1.03-1.39). CONCLUSIONS: An increase in blood culture contaminations and ICU-BSIs was observed during the second COVID-19 pandemic wave, especially in months when the ICU burden of COVID-19 patients was high.

Distribution of pathogens and antimicrobial resistance in ICU-bloodstream infections during hospitalization: a nationwide surveillance study.

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.