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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 remains challenging.
We report the first documented in-hospital patient-to-patient-transmission of a blaVIM-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.
The incidence of surgical site infections may be underreported if the data are not routinely validated for accuracy. Our goal was to investigate the communicated SSI rate from a large network of Swiss hospitals compared with the results from on-site surveillance quality audits.
Retrospective cohort study.
In total, 81,957 knee and hip prosthetic arthroplasties from 125 hospitals and 33,315 colorectal surgeries from 110 hospitals were included in the study.
Hospitals had at least 2 external audits to assess the surveillance quality. The 50-point standardized score per audit summarizes quantitative and qualitative information from both structured interviews and a random selection of patient records. We calculated the mean National Healthcare Safety Network (NHSN) risk index adjusted infection rates in both surgery groups.
The median NHSN adjusted infection rate per hospital was 1.0% (interquartile range [IQR], 0.6%–1.5%) with median audit score of 37 (IQR, 33–42) for knee and hip arthroplasty, and 12.7% (IQR, 9.0%–16.6%), with median audit score 38 (IQR, 35–42) for colorectal surgeries. We observed a wide range of SSI rates and surveillance quality, with discernible clustering for public and private hospitals, and both lower infection rates and audit scores for private hospitals. Infection rates increased with audit scores for knee and hip arthroplasty (P value for the slope = .002), and this was also the case for planned (P = .002), and unplanned (P = .02) colorectal surgeries.
Surveillance systems without routine evaluation of validity may underestimate the true incidence of SSIs. Audit quality should be taken into account when interpreting SSI rates, perhaps by adjusting infection rates for those hospitals with lower audit scores.
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.
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 surgeries.
To determine whether colonization with extended-spectrum β-lactamase–producing Enterobacteriaceae (ESBL-PE) predicts the risk for subsequent infection and impacts carbapenem-consumption and outcome in intensive care unit (ICU) patients.
Prospective cohort study.
The 2 ICUs in the University Hospital Basel in Switzerland.
All patients admitted to the 2 ICUs providing mechanical ventilation and an expected ICU stay >48 hours.
Patients were routinely screened for ESBL-PE carriage by rectal swab on admission. Competing risk regression analyses were applied to calculate hazard ratios (HRs) for infection with ESBL-PE and mortality. Length of hospital stay, length of ICU stay, and duration of carbapenem exposure were compared using the Mann-Whitney U test.
Among 302 patients, 24 (8.0%) were colonized with ESBL-PE on ICU admission. Infections with ESBL-PE occurred in 4 patients, of whom 3 (75%) were identified as ESBL-PE colonized on admission. ESBL-PE colonization on admission was associated with subsequent ESBL-PE infection (hazard ratio [HR], 25.52; 95% confidence interval [CI], 2.40–271.41; P = .007) and exposure to carbapenems (HR, 2.42; 95% CI, 1.01–5.79; P = .047), whereas duration of carbapenem exposure did not differ in relation to ESBL-PE colonization (median, 7 days [IQR, 3–8 days] vs median, 6 days [IQR 3–9 days]; P = 0.983). Patients colonized with ESBL-PE were not at increased risk for death overall (HR, 1.00; 95% CI, 0.44–2.30; P = .993) or death attributable to infection (HR, 1.20; 95% CI, 0.28–5.11; P = .808).
Screening strategies for detection of ESBL-PE colonization on ICU admission may allow the identification of patients at highest risk for ESBL-PE infection and the correct allocation of empiric carbapenem treatment.
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 learning and its first applications in the emerging field of digital healthcare epidemiology.
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.
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.
Prospective observational study.
University Hospital Basel, Switzerland.
Continuous microbiological surveillance of 3 types of HCUs in use (3T from LivaNova/Sorin and HCU30 and HCU40 from Maquet) was initiated in June 2014, coupled with an epidemiologic workup. Monthly water and air samples were taken. Construction design was analyzed, and exhausted airflow was measured.
Mycobacterium chimaera grew in 8 of 12 water samples (66%) and 22 of 24 air samples (91%) of initial 3T HCUs in use, and in 2 of 83 water samples (2%) and 0 of 41 (0%) air samples of new replacement 3T HCUs. Moreover, 7 of 12 water samples (58%) and 0 of 4 (0%) air samples from the HCU30 were positive, and 0 of 64 (0%) water samples and 0 of 50 (0%) air samples from the HCU40 were positive. We identified 4 relevant differences in HCU design compared to the 3T: air flow direction, location of cooling ventilators, continuous cooling of the water tank at 4°C, and an electronic alarm in the HCU40 reminding the user of the next disinfection cycle.
All infected patients were associated with a 3T HCU. The individual HCU design may explain the different risk of disseminating M. chimaera into the air of the operating room. These observations can help the construction of improved devices to ensure patient safety during cardiac surgery.
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.
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.
Retrospective cohort study.
Adults with a positive PCR test result for RSV who were hospitalized in a tertiary academic medical center between January 2015 and December 2016 were included in this study. Our infection control policy applies contact isolation precautions only for immunocompromised patients.
Patients were identified through 2 databases, 1 consisting of patients isolated because of RSV infection and 1 with automatically collected laboratory results. Baseline and clinical characteristics were collected through a retrospective medical chart review. The rate of and clinical factors associated with healthcare-associated RSV infections were evaluated.
In total, 108 episodes in 106 patients hospitalized with a positive Xpert RSV test result were recorded during the study period. Among them, 11 episodes were healthcare-associated infections (HAIs) and 97 were community-acquired infections (CAIs). The mean length of hospital stay (LOS, 40.2 vs 11.2 days), the mean number of room switches (3.5 vs 1.7) and ward switches (1.5 vs 0.4), and the mean numbers of contact patients (9.9 vs 3.8) were significantly longer and higher in the HAI group than in the CAI group (P<.0001). Surveillance of microbiology records and clinical data did not reveal evidence for a cluster or an epidemic during the 2-year observation period.
The introduction of a rapid molecular diagnostic test systematically applied to patients with influenza-like illness may challenge current infection control policies. In our study, patients with HAIs had a prolonged hospital stay and a high number of contact patients, and they switched rooms and wards frequently.
Distinguishing recurrent Clostridium difficile infection (CDI), defined as CDI caused by the same genotype, from reinfection with a different genotype, has important implications for surveillance and clinical trials investigating treatment effectiveness. We validated the proposed 8-week period for distinguishing “same genotype CDI” from “different genotype CDI,” and we aimed to identify clinical variables with distinctiveness to propose an improved definition.
From January 2004 to December 2013, a cohort of all inpatients with CDI at the University Hospital Basel, Switzerland, was established, and respective strains were collected. In patients with a second episode of CDI, both strains were compared using polymerase chain reaction (PCR) ribotyping. The standard definition of recurrence (within 8 weeks after initial diagnosis) was evaluated for its performance to predict CDI caused by the same genotype.
Among 750 patients with CDI, 130 (17.3%) were diagnosed with recurrence or reinfection. Strains from both episodes were available from 106 patients. Identical strains were identified in 36 patients with recurrence (36 of 47) and 27 patients with reinfection (27 of 59). Sensitivity, specificity, and negative and positive predictive values of the standard definition were 56%, 74%, 53%, and 76%, respectively. An extended period of 20 weeks resulted in the best match for both sensitivity and specificity (83% and 58%, respectively), while none of the clinical characteristics revealed independent distinctive power.
Our results challenge the utility of the 8-week cutoff for distinguishing recurrent CDI from reinfection. An extended period of 20 weeks may result in improved overall performance characteristics, but this finding requires external validation.
To report on the results of the Swiss national surgical site infection (SSI) surveillance program, including temporal trends, and to describe methodological characteristics that may influence SSI rates
Countrywide survey of SSI over a 4-year period. Analysis of prospectively collected data including patient and procedure characteristics as well as aggregated SSI rates stratified by risk categories, type of SSI, and time of diagnosis. Temporal trends were analyzed using stepwise multivariate logistic regression models with adjustment of the effect of the duration of participation in the surveillance program for confounding factors.
The study included 164 Swiss public and private hospitals with surgical activities.
From October 2011 to September 2015, a total of 187,501 operations performed in this setting were included. Cumulative SSI rates varied from 0.9% for knee arthroplasty to 14.4% for colon surgery. Postdischarge follow-up was completed in >90% of patients at 1 month for surgeries without an implant and in >80% of patients at 12 months for surgeries with an implant. High rates of SSIs were detected postdischarge, from 20.7% in colon surgeries to 93.3% in knee arthroplasties. Overall, the impact of the duration of surveillance was significantly and independently associated with a decrease in SSI rates in herniorraphies and C-sections but not for the other procedures. Nevertheless, some hospitals observed significant decreases in their rates for various procedures.
Intensive post-discharge surveillance may explain high SSI rates and cause artificial differences between programs. Surveillance per se, without structured and mandatory quality improvement efforts, may not produce the expected decrease in SSI rates.
Infections and colonization with multidrug-resistant organisms (MDROs) identified >48 hours after hospital admission are considered healthcare-acquired according to the definition of the Centers for Disease Control and Prevention (CDC). Some may originate from delayed diagnosis rather than true acquisition in the hospital, potentially diluting the impact of infection control programs. In addition, such infections are not necessarily reimbursed in a healthcare system based on the diagnosis-related groups (DRGs).
The goal of the study was to estimate the preventable proportion of healthcare-acquired infections in a tertiary care hospital in Switzerland by analyzing patients colonized or infected with MDROs.
All hospitalized patients with healthcare-acquired MDRO infection or colonization (HAMIC) or according to the CDC definition (CDC-HAMIC) were prospectively assessed from 2002 to 2011 to determine whether there was evidence for nosocomial transmission. We utilized an additional work-up with epidemiological, microbiological, and molecular typing data to determine the true preventable proportion of HAMICs.
Overall, 1,190 cases with infection or colonization with MDROs were analyzed; 274 (23.0%) were classified as CDC-HAMICs. Only 51.8% of CDC-HAMICs had confirmed evidence of hospital-acquisition and were considered preventable. Specifically, 57% of MRSA infections, 83.3% of VRE infections, 43.9% of ESBL infections, and 74.1% of non-ESBL MDRO infections were preventable HAMICs.
The CDC definition overestimates the preventable proportion of HAMICs with MDROs by more than 50%. Relying only on the CDC definition of HAMICs may lead to inaccurate measurement of the impact of infection control interventions and to inadequate reimbursement under the DRG system.
Clostridium difficile infection (CDI) in hospitalized patients is generally attributed to the current stay, but recent studies reveal high C. difficile colonization rates on admission.
To determine the rate of colonization with toxigenic C. difficile among intensive care unit patients upon admission as well as acquired during hospitalization, and the risk of subsequent CDI.
Prospective cohort study from April 15 through July 8, 2013. Adults admitted to an intensive care unit within 48 hours of admission to the Johns Hopkins Hospital, Baltimore, Maryland, were screened for colonization with toxigenic C. difficile. The primary outcome was risk of developing CDI.
Among 542 patients, 17 (3.1%) were colonized with toxigenic C. difficile on admission and an additional 3 patients were found to be colonized during hospitalization. Both colonization with toxigenic C. difficile on admission and colonization during hospitalization were associated with an increased risk for development of CDI (relative risk, 10.29 [95% CI, 2.24–47.40], P=.003; and 15.66 [4.01–61.08], P<.001, respectively). Using multivariable analysis, colonization on admission and colonization during hospitalization were independent predictors of CDI (relative risk, 8.62 [95% CI, 1.48–50.25], P=.017; and 10.93 [1.49–80.20], P=.019, respectively), while adjusting for potential confounders.
In intensive care unit patients, colonization with toxigenic C. difficile is an independent risk factor for development of subsequent CDI. Further studies are needed to identify populations with higher toxigenic C. difficile colonization rates possibly benefiting from screening or avoidance of agents known to promote CDI.
Infect. Control Hosp. Epidemiol. 2015;36(11):1324–1329
Methicillin-resistant Staphylococcus aureus (MRSA) is a worldwide issue associated with significant morbidity and mortality. Multiple infection control (IC) approaches have been tested to control its spread; however, the success of the majority of trials has been short-lived and many efforts have failed. We report the long-term success of MRSA control from a prospective observational study over 20 years.
University Hospital Basel is a large tertiary care center with a median bed capacity of 855 and 5 intensive care units (ICUs); currently, the facility has >32,000 admissions per year.
The IC program at the University Hospital Basel was created in 1993, after 2 MRSA outbreaks. The program has included strict contact precautions with single rooms for MRSA-colonized or -infected patients, targeted admission screening of high-risk patients and healthcare workers at risk for carriage, molecular typing of all MRSA strains and routine decolonization of MRSA carriers including healthcare workers. We used the incidence of MRSA bloodstream infections (BSIs) to assess the effectiveness of this program. All MRSA cases were prospectively classified using a standardized case report form in nosocomial and nonnosocomial cases, based on CDC definitions.
Between 1993 and 2012, 540,669 blood samples were cultured. The number of blood cultures increased from 865 per 10,000 patient days in 1993 to 1,568 per 10,000 patient days in 2012 (P<.001). We identified 1,268 episodes of S. aureus BSI from 1,204 patients. MRSA accounted for 34 episodes (2.7%) and 24 of these (1.9%) were nosocomial. MRSA BSI incidence varied between 0 and 0.27 per 10,000 patient days and remained stable with no significant variation throughout the study period (P=.882).
Long-term control of MRSA is feasible when a bundle of IC precautions is strictly enforced over time.