Genetic Determinants in MRSA Carriage and Their Association with Decolonization Outcome.

Methicillin-resistant Staphylococcus aureus (MRSA) colonization increases the risk of infection. Response to decolonization treatment is highly variable and determinants for successful decolonization or failure of eradication treatment are largely unknown. Insight into genetic predictors of eradication failure is potentially useful in clinical practice. The aim of this study was to explore genetic characteristics that are associated with MRSA decolonization failure. This cohort study was performed in a tertiary care hospital in the Netherlands. Patients with ≥ 1 positive MRSA culture from any site and with available whole -genome sequencing data of the MRSA isolate between 2017 and 2022 were included. Lineages, resistance, and virulence factors were stratified by MRSA decolonization outcome. In total, 56 patients were included: 12/56 (21%) with treatment failure and 44/56 (79%) with successful decolonization (with or without preceding treatment). A significant association was found between ciprofloxacin-resistant lineages and failure of eradication (OR 4.20, 95%CI 1.11-15.96, P = 0.04). Furthermore, livestock-associated MRSA and the major community-associated MRSA lineages ST6-t304 and ST8-t008 were associated with successful eradication treatment or spontaneous clearance. In conclusion, this explorative study showed a higher eradication failure rate in complicated MRSA carriers with ciprofloxacin-resistant MRSA lineages, which are predominantly healthcare-associated. Further studies are warranted to confirm the higher eradication failure risk of ciprofloxacin-resistant lineages, and identify the underlying mechanisms.

Long-read sequencing-based in silico phage typing of vancomycin-resistant Enterococcus faecium.

BACKGROUND: Vancomycin-resistant enterococci (VRE) are successful nosocomial pathogens able to cause hospital outbreaks. In the Netherlands, core-genome MLST (cgMLST) based on short-read sequencing is often used for molecular typing. Long-read sequencing is more rapid and provides useful information about the genome's structural composition but lacks the precision required for SNP-based typing and cgMLST. Here we compared prophages among 50 complete E. faecium genomes belonging to different lineages to explore whether a phage signature would be usable for typing and identifying an outbreak caused by VRE. As a proof of principle, we investigated if long-read sequencing data would allow for identifying phage signatures and thereby outbreak-related isolates. RESULTS: Analysis of complete genome sequences of publicly available isolates showed variation in phage content among different lineages defined by MLST. We identified phage present in multiple STs as well as phages uniquely detected within a single lineage. Next, in silico phage typing was applied to twelve MinION sequenced isolates belonging to two different genetic backgrounds, namely ST117/CT24 and ST80/CT16. Genomic comparisons of the long-read-based assemblies allowed us to correctly identify isolates of the same complex type based on global genome architecture and specific phage signature similarity. CONCLUSIONS: For rapid identification of related VRE isolates, phage content analysis in long-read sequencing data is possible. This allows software development for real-time typing analysis of long-read sequencing data, which will generate results within several hours. Future studies are required to assess the discriminatory power of this method in the investigation of ongoing outbreaks over a longer time period.

Passive Tracer Visualization to Simulate Aerodynamic Virus Transport in Noninvasive Respiratory Support Methods.

BACKGROUND: Various forms of noninvasive respiratory support methods are used in the treatment of hypoxemic CO-VID-19 patients, but limited data are available about the corresponding respiratory droplet dispersion. OBJECTIVES: The aim of this study was to estimate the potential spread of infectious diseases for a broad selection of oxygen and respiratory support methods by revealing the therapy-induced aerodynamics and respiratory droplet dispersion. METHODS: The exhaled air-smoke plume from a 3D-printed upper airway geometry was visualized by recording light reflection during simulated spontaneous breathing, standard oxygen mask application, nasal high-flow therapy (NHFT), continuous positive airway pressure (CPAP), and bilevel positive airway pressure (BiPAP). The dispersion of 100 µm particles was estimated from the initial velocity of exhaled air and the theoretical terminal velocity. RESULTS: Estimated droplet dispersion was 16 cm for unassisted breathing, 10 cm for Venturi masks, 13 cm for the nebulizer, and 14 cm for the nonrebreathing mask. Estimated droplet spread increased up to 34 cm in NHFT, 57 cm in BiPAP, and 69 cm in CPAP. A nonsurgical face mask over the NHFT interface reduced estimated droplet dispersion. CONCLUSIONS: During NHFT and CPAP/BiPAP with vented masks, extensive jets with relatively high jet velocities were observed, indicating increased droplet spread and an increased risk of droplet-driven virus transmission. For the Venturi masks, a nonrebreathing mask, and a nebulizer, estimated jet velocities are comparable to unassisted breathing. Aerosols are transported unboundedly in all these unfiltered therapies. The adequate use of protective measures is of vital importance when using noninvasive unfiltered therapies in infectious respiratory diseases.

Epidemiological Typing of Serratia marcescens Isolates by Whole-Genome Multilocus Sequence Typing.

Serratia marcescens is an opportunistic bacterial pathogen. It is notorious for its increasing antimicrobial resistance and its potential to cause outbreaks of colonization and infections, predominantly in neonatal intensive care units (NICUs). There, its spread requires rapid infection control response. To understand its spread, detailed molecular typing is key. We present a whole-genome multilocus sequence typing (wgMLST) method for S. marcescens Using a set of 299 publicly available whole-genome sequences (WGS), we developed an initial wgMLST system consisting of 9,377 gene loci. This included 1,455 loci occurring in all reference genomes and 7,922 accessory loci. This closed system was validated using three geographically diverse collections of S. marcescens consisting of 111 clinical isolates implicated in nosocomial dissemination events in three hospitals. The validation procedure showed a full match between epidemiological data and the wgMLST analyses. We set the cutoff value for epidemiological (non)relatedness at 20 different alleles, though for the majority of outbreak-clustered isolates, this difference was limited to 4 alleles. This shows that the wgMLST system for S. marcescens provides prospects for successful future monitoring for the epidemiological containment of this opportunistic pathogen.

Rapid Analysis of Diagnostic and Antimicrobial Patterns in R (RadaR): Interactive Open-Source Software App for Infection Management and Antimicrobial Stewardship.

BACKGROUND: Analyzing process and outcome measures for all patients diagnosed with an infection in a hospital, including those suspected of having an infection, requires not only processing of large datasets but also accounting for numerous patient parameters and guidelines. Substantial technical expertise is required to conduct such rapid, reproducible, and adaptable analyses; however, such analyses can yield valuable insights for infection management and antimicrobial stewardship (AMS) teams. OBJECTIVE: The aim of this study was to present the design, development, and testing of RadaR (Rapid analysis of diagnostic and antimicrobial patterns in R), a software app for infection management, and to ascertain whether RadaR can facilitate user-friendly, intuitive, and interactive analyses of large datasets in the absence of prior in-depth software or programming knowledge. METHODS: RadaR was built in the open-source programming language R, using Shiny, an additional package to implement Web-app frameworks in R. It was developed in the context of a 1339-bed academic tertiary referral hospital to handle data of more than 180,000 admissions. RESULTS: RadaR enabled visualization of analytical graphs and statistical summaries in a rapid and interactive manner. It allowed users to filter patient groups by 17 different criteria and investigate antimicrobial use, microbiological diagnostic use and results including antimicrobial resistance, and outcome in length of stay. Furthermore, with RadaR, results can be stratified and grouped to compare defined patient groups on the basis of individual patient features. CONCLUSIONS: AMS teams can use RadaR to identify areas within their institutions that might benefit from increased support and targeted interventions. It can be used for the assessment of diagnostic and therapeutic procedures and for visualizing and communicating analyses. RadaR demonstrated the feasibility of developing software tools for use in infection management and for AMS teams in an open-source approach, thus making it free to use and adaptable to different settings.

Isolation of an NDM-5-producing ST16 Klebsiella pneumoniae from a Dutch patient without travel history abroad, August 2015.

A New Delhi Metallo-beta-lactamase-5 (NDM-5)-producing ST16 Klebsiella pneumoniae strain was isolated from a Dutch patient in a long-term care facility without recent travel history abroad. Core genome multilocus sequence typing (cgMLST) revealed that the Dutch isolate was clonally related to isolates detected in four patients in Denmark in 2014. Public health experts and clinicians need to be informed; repetitive screening may be needed in patients without known risk factors for carbapenemases-producing Enterobacteriaceae who have undergone antibiotic treatment.

Molecular epidemiology of a Parainfluenza Type 3 virus outbreak: Informing infection control measures on adult hematology wards.

OBJECTIVES: Parainfluenza virus type 3 (PIV3) outbreaks among hematology patients are associated with high morbidity and mortality. Prompt implementation of infection prevention (IP) measures has proven to be the most efficacious approach for controlling PIV3 outbreaks within this patient population. The most suitable IP measures can vary depending on the mode of virus transmission, which remains unidentified in most outbreaks. We describe the molecular epidemiology of an outbreak of PIV3 among hematology patients and the development of a new method that allows for the differentiation of outbreak and community strains, from which a closed outbreak could be inferred. METHODS: Patients were screened for respiratory viruses using multiplex-PCR. PIV3 positive samples with a cycle threshold (Ct)-value of <31 underwent a retrospective characterization via an in-house developed sequence analysis of the hemagglutinin-neuraminidase (HN) gene. RESULTS: Between July and September 2022, 31 hematology patients were identified with PIV3. Although infection control measures were implemented, the outbreak persisted for nine weeks. Sequencing the HN gene of 27 PIV3 strains from 27 patients revealed that all outbreak strains formed a distinct cluster separate from the control strains, suggestive of a nosocomial transmission route. CONCLUSIONS: Sequencing the HN gene of PIV3 strains in an outbreak setting enables outbreak strains to be distinguished from community strains. Early molecular characterization of PIV3 strains during an outbreak can serve as a tool in determining potential transmission routes. This, in turn, enables rapid implementation of targeted infection prevention measures, with the goal of minimizing the outbreak's duration and reducing associated morbidity and mortality.

Uncovering the spread of drug-resistant bacteria through next-generation sequencing based surveillance: transmission of extended-spectrum ß-lactamase-producing Enterobacterales by a contaminated duodenoscope.

Contamination of duodenoscopes is a significant concern due to the transmission of multidrug-resistant organisms (MDROs) among patients who undergo endoscopic retrograde cholangiopancreatography (ERCP), resulting in outbreaks worldwide. In July 2020, it was determined that three different patients, all had undergone ERCP with the same duodenoscope, were infected. Two patients were infected with blaCTX-M-15 encoding Citrobacter freundii, one experiencing a bloodstream infection and the other a urinary tract infection, while another patient had a bloodstream infection caused by blaSHV-12 encoding Klebsiella pneumoniae. Molecular characterization of isolates was available as every ESBL-producing isolate undergoes Next-Generation Sequencing (NGS) for comprehensive genomic analysis in our center. After withdrawing the suspected duodenoscope, we initiated comprehensive epidemiological research, encompassing case investigations, along with a thorough duodenoscope investigation. Screening of patients who had undergone ERCP with the implicated duodenoscope, as well as a selection of hospitalized patients who had ERCP with a different duodenoscope during the outbreak period, led to the discovery of three additional cases of colonization in addition to the three infections initially detected. No microorganisms were detected in eight routine culture samples retrieved from the suspected duodenoscope. Only after destructive dismantling of the duodenoscope, the forceps elevator was found to be positive for blaSHV-12 encoding K. pneumoniae which was identical to the isolates detected in three patients. This study highlights the importance of using NGS to monitor the transmission of MDROs and demonstrates that standard cultures may fail to detect contaminated medical equipment such as duodenoscopes.

Age-related changes in mammographic density and breast cancer risk.

High mammographic density is a strong breast cancer risk factor. Density normally declines with aging. We investigated whether the level of decline in mammographic density is related to breast cancer risk using a nested case-control study within the European Prospective Investigation into Cancer and Nutrition (EPIC)-Prospect cohort. This cohort was recruited among participants of a population-based breast cancer screening program in the Netherlands between 1993 and 1997. We examined whether age-related changes in mammographic density were different for 533 cases and 1,367 controls who were 49-69 years of age at the time of recruitment into the cohort. We used mixed models with linear and quadratic terms for age and interaction terms between age terms and case status. The percent mammographic density at the first available mammogram was higher for cases than for controls (25.2% vs. 22.5%) (P = 0.003). The average decline in density over 10 years was 11% in both cases and controls (P = 0.56). When studying changes among 4 categories of density, we saw some indication that large changes may influence breast cancer risk. Although no difference was seen in the average decline, we cannot exclude that large changes may influence breast cancer risk.

Early life factors and adult mammographic density.

PURPOSE: Early life factors have shown to be related to breast cancer risk. The pathophysiological link could be mammographic density, a strong risk factor for breast cancer. Mammary gland development already starts in utero and early life factors might affect the number of mammary cells at risk. In this study, we investigated the association between early life factors and mammographic density in adulthood. METHODS: The study was conducted within 2,588, mainly postmenopausal women of the Prospect-European Prospective Investigation into Cancer and Nutrition cohort. This ongoing study recruited breast cancer screening participants who filled out extensive questionnaires. Information on the early life factors birth weight, gestational age, maternal and paternal age, multiple births, birth rank, exposure to parental smoking, and leg length as a proxy for growth at childhood was obtained using questionnaires. Generalized linear models and linear regression models were used to study the relation between early life factors and mammographic density. Analyses were adjusted for potential confounders. RESULTS: Women who had an older mother (p = 0.06) or father (p = 0.002) at birth tended to have a higher mammographic density. Furthermore, greater leg length seemed to be related to higher mammographic density, although not statistically significantly (p = 0.16). After adjustment for confounders, none of the early life factors showed any statistically significant relationship with mammographic density in adulthood. CONCLUSION: Although we cannot exclude small effects that go undetected due to measurement error in recall of early life factors, the results suggest that mammographic density is not a major pathway in any observed relationship between these early life events and breast cancer risk.

Costs of two vancomycin-resistant enterococci outbreaks in an academic hospital.

Objective: In early 2017, the University Medical Center Groningen, the Netherlands, had an outbreak of 2 strains of vancomycin-resistant enterococci (VRE) that spread to various wards. In the summer of 2018, the hospital was again hit by a VRE outbreak, which was detected and controlled early. However, during both outbreaks, fewer patients were admitted to the hospital and various costs were incurred. We quantified the costs of the 2017 and 2018 VRE outbreaks. Design: Using data from various sources in the hospital and interviews, we identified and quantified the costs of the 2 outbreaks, resulting from tests, closed beds (opportunity costs), cleaning, additional personnel, and patient isolation. Setting: The University Medical Center Groningen, an academic hospital in the Netherlands. Results: The total costs associated with the 2017 outbreak were estimated to be €335,278 (US $356,826); the total costs associated with the 2018 outbreak were estimated at €149,025 (US $158,602). Conclusions: The main drivers of the costs were the opportunity costs due to the reduction in admitted patients, testing costs, and cleaning costs. Although the second outbreak was considerably shorter, the costs per day were similar to those of the first outbreak. Major investments are associated with the VRE control measures, and an outbreak of VRE can lead to considerable costs for a hospital. Aggressively screening and isolating patients who may be involved in an outbreak of VRE may reduce the overall costs and improve the continuity of care within the hospital.

Better antimicrobial resistance data analysis and reporting in less time.

Objectives: Insights about local antimicrobial resistance (AMR) levels and epidemiology are essential to guide decision-making processes in antimicrobial use. However, dedicated tools for reliable and reproducible AMR data analysis and reporting are often lacking. We aimed to compare traditional data analysis and reporting versus a new approach for reliable and reproducible AMR data analysis in a clinical setting. Methods: Ten professionals who routinely work with AMR data were provided with blood culture test results including antimicrobial susceptibility results. Participants were asked to perform a detailed AMR data analysis in a two-round process: first using their software of choice and next using our newly developed software tool. Accuracy of the results and time spent were compared between both rounds. Finally, participants rated the usability using the System Usability Scale (SUS). Results: The mean time spent on creating the AMR report reduced from 93.7 to 22.4 min (P < 0.001). Average task completion per round changed from 56% to 96% (P < 0.05). The proportion of correct answers in the available results increased from 37.9% in the first to 97.9% in the second round (P < 0.001). Usability of the new tools was rated with a median of 83.8 (out of 100) on the SUS. Conclusions: This study demonstrated the significant improvement in efficiency and accuracy in standard AMR data analysis and reporting workflows through open-source software. Integrating these tools in clinical settings can democratize the access to fast and reliable insights about local microbial epidemiology and associated AMR levels. Thereby, our approach can support evidence-based decision-making processes in the use of antimicrobials.

Vancomycin-resistant enterococci (VRE) in hospital settings across European borders: a scoping review comparing the epidemiology in the Netherlands and Germany.

The rising prevalence of vancomycin-resistant enterococci (VRE) is a matter of concern in hospital settings across Europe without a distinct geographical pattern. In this scoping review, we compared the epidemiology of vancomycin-resistant Enterococcus spp. in hospitals in the Netherlands and Germany, between 1991 and 2022. We searched PubMed and summarized the national antibiotic resistance surveillance data of the two countries. We included 46 studies and summarized national surveillance data from the NethMap in the Netherlands, the National Antimicrobial Resistance Surveillance database in Germany, and the EARS-Net data. In total, 12 studies were conducted in hospitals in the Netherlands, 32 were conducted in German hospitals, and an additional two studies were conducted in a cross-border setting. The most significant difference between the two countries was that studies in Germany showed an increasing trend in the prevalence of VRE in hospitals, and no such trend was observed in studies in the Netherlands. Furthermore, in both Dutch and German hospitals, it has been revealed that the molecular epidemiology of VREfm has shifted from a predominance of vanA towards vanB over the years. According to national surveillance reports, vancomycin resistance in Enterococcus faecium clinical isolates fluctuates below 1% in Dutch hospitals, whereas it follows an increasing trend in German hospitals (above 20%), as supported by individual studies. This review demonstrates that VRE is more frequently encountered in German than in Dutch hospitals and discusses the underlying factors for the difference in VRE occurrence in these two neighboring countries by comparing differences in healthcare systems, infection prevention control (IPC) guidelines, and antibiotic use in the Netherlands and Germany.

The effect of moral appeals on influenza vaccination uptake and support for a vaccination mandate among health care workers.

OBJECTIVE: Influenza vaccination uptake among health care workers (HCWs) protects patients and staff. Still, many health institutions' coverage rates are unsatisfactory. We aimed to test the effect of communicating moral appeals in increasing vaccination uptake in a real life setting. METHOD: In three field experiments among HCWs, a moral appeal highlighting morally relevant consequences of influenza vaccination was manipulated. The outcome variables were vaccination intention right after exposure to the moral appeal (Study 1; N = 569 US and UK HCWs from various institutions) and vaccination uptake in subsequent weeks for those respondents who consented in sharing this data during the survey (Studies 2 and 3, respectively N = 121 and N = 770 Dutch hospital employees). RESULTS: Studies 1 and 3 showed that moral appeal enhanced vaccination intention and uptake (vaccination uptake increased by 11%), due to increased awareness that vaccination is a moral decision. In Study 2, moral appeal had no effect, probably because people with more outspoken vaccination attitudes had responded to the call to fill in the survey. Moreover, moral appeal increased support for an influenza vaccination mandate. Furthermore, the results suggest that moral appeal was especially effective among HCWs with no history of influenza vaccination. CONCLUSION: These results indicate that moral appeal can be a useful tool for increasing both vaccination uptake and mandate support within health care institutions.

Mammographic density and breast cancer risk: the role of the fat surrounding the fibroglandular tissue.

INTRODUCTION: Both the percent of mammographic density and absolute dense (fibroglandular) area are strong breast cancer risk factors. The role of non-dense (fat) breast tissue is not often investigated, but we hypothesize that this also influences risk. In this study we investigated the independent effects of dense and fat tissue, as well as their combined effect on postmenopausal breast cancer risk. METHODS: We performed a nested case-control study within the EPIC-NL cohort (358 postmenopausal breast cancer cases and 859 postmenopausal controls). We used multivariate logistic regression analyses to estimate breast cancer odds ratios adjusted for body mass index and other breast cancer risk factors. RESULTS: Large areas of dense (upper (Q5) vs lower quintile (Q1): OR 2.8 95% CI 1.7 to 4.8) and fat tissue (Q5 vs Q1: OR 2.4; 95% CI 1.3 to 4.2) were independently associated with higher breast cancer risk. The combined measure showed that the highest risk was found in women with both a large (above median) area of dense and fat tissue. CONCLUSIONS: Fibroglandular and breast fat tissue have independent effects on breast cancer risk. The results indicate that the non-dense tissue, which represents the local breast fat, increases risk, even independent of body mass index (BMI). When studying dense breast tissue in relation to breast cancer risk, adjustment for non-dense tissue seems to change risk estimates to a larger extent than adjustment for BMI. This indicates that adjustment for non-dense tissue should be considered when studying associations between dense areas and breast cancer risk.

Compliance to Screening Protocols for Multidrug-Resistant Microorganisms at the Emergency Departments of Two Academic Hospitals in the Dutch-German Cross-Border Region.

Infections caused by multidrug-resistant organisms (MDROs) are associated with prolonged hospitalization and higher risk of mortality. Patients arriving in the hospital via the emergency department (ED) are screened for the presence of MDROs in compliance with the screening protocols in order to apply the correct isolation measures. In the Dutch-German border region, local hospitals apply their own screening protocols which are based upon national screening protocols. The contents of the national and local MDRO screening protocols were compared on vancomycin-resistant enterococci (VRE), methicillin-resistant Staphylococcus aureus (MRSA), and carbapenemase-producing and carbapenem-resistant Enterobacteriaceae (CPE/CRE). The practicality of the screening protocols was evaluated by performing an audit. As a result, the content of the MDRO screening protocols differed regarding risk factors for MDRO carriage, swab site, personal protective equipment, and isolation measures. The observations and questionnaires showed that the practicality was sufficient; however, the responsibility was not designated clearly and education regarding the screening protocols was deemed inappropriate. The differences between the MDRO screening protocols complicate patient care in the Dutch-German border region. Arrangements have to be made about the responsibility of the MDRO screening, and improvements are necessary concerning education regarding the MDRO screening protocols.

Molecular Characterisation of Vancomycin-Resistant Enterococcus faecium Isolates Belonging to the Lineage ST117/CT24 Causing Hospital Outbreaks.

Background: Vancomycin-resistant Enterococcus faecium (VREfm) is a successful nosocomial pathogen. The current molecular method recommended in the Netherlands for VREfm typing is based on core genome Multilocus sequence typing (cgMLST), however, the rapid emergence of specific VREfm lineages challenges distinguishing outbreak isolates solely based on their core genome. Here, we explored if a detailed molecular characterisation of mobile genetic elements (MGEs) and accessory genes could support and expand the current molecular typing of VREfm isolates sharing the same genetic background, enhancing the discriminatory power of the analysis. Materials/Methods: The genomes of 39 VREfm and three vancomycin-susceptible E. faecium (VSEfm) isolates belonging to ST117/CT24, as assessed by cgMLST, were retrospectively analysed. The isolates were collected from patients and environmental samples from 2011 to 2017, and their genomes were analysed using short-read sequencing. Pangenome analysis was performed on de novo assemblies, which were also screened for known predicted virulence factors, antimicrobial resistance genes, bacteriocins, and prophages. Two representative isolates were also sequenced using long-read sequencing, which allowed a detailed analysis of their plasmid content. Results: The cgMLST analysis showed that the isolates were closely related, with a minimal allelic difference of 10 between each cluster's closest related isolates. The vanB-carrying transposon Tn1549 was present in all VREfm isolates. However, in our data, we observed independent acquisitions of this transposon. The pangenome analysis revealed differences in the accessory genes related to prophages and bacteriocins content, whilst a similar profile was observed for known predicted virulence and resistance genes. Conclusion: In the case of closely related isolates sharing a similar genetic background, a detailed analysis of MGEs and the integration point of the vanB-carrying transposon allow to increase the discriminatory power compared to the use of cgMLST alone. Thus, enabling the identification of epidemiological links amongst hospitalised patients.

Viral load dynamics in intubated patients with COVID-19 admitted to the intensive care unit.

BACKGROUND: Prolonged viral RNA detection in respiratory samples from patients with COVID-19 has been described, but the clinical relevance remains unclear. We studied the dynamics of SARS-CoV-2 on a group and individual level in intubated ICU patients. METHODS: In a cohort of 86 patients, we analysed SARS-CoV-2 RT-PCR results on nasopharyngeal and sputum samples (obtained as part of clinical care twice a week) according to time after intubation. Subsequently, we performed survival analyses. RESULTS: 870 samples were tested by RT-PCR. Overall viral load was highest in the first week (median nasopharynx 3.5, IQR 1.5-4.3; median sputum 4.3, IQR 3.3-5.6) and decreased over time. In 20% of patients a relapsing pattern was observed. Nasopharyngeal and sputum PCR status on day 14 was not significantly associated with survival up to day 60 in this small cohort. CONCLUSION: In general SARS-CoV-2 RNA levels in respiratory samples in patients with severe COVID-19 decrease after the first week after intubation, but individual SARS-CoV-2 RNA levels can show a relapsing pattern. Larger studies are needed to address the association of clearance of SARS-CoV-2 RNA from respiratory samples with survival, because we observed a trend towards better survival in patients with early clearance from sputum.

The influence of a period of caloric restriction due to the Dutch famine on breast density.

Recently, we showed that short, intense caloric restriction due to the Dutch famine increased breast cancer risk in women and influenced the hormonal- and IGF-system. These systems may also affect breast density, which is one of the strongest risk factors for breast cancer. We examined the influence of the Dutch famine on breast density, using mammograms of 1,035 women. Breast size, dense and non-dense tissue and the relative density were measured on a continuous scale. Mean density was compared between three groups of ascending levels of famine-exposure. Results were adjusted for known determinants of breast density and stratified by age at exposure. There were no overall, significant differences by exposure. In unexposed compared to severely exposed women, means varied from 124 cm(2) to 121 cm(2) (p(trend) = 0.50) for breast size, from 23.4 to 21.8 cm(2) (p(trend) = 0.48) for amount of dense tissue, from 87.7 to 85.4 cm(2) (p(trend) = 0.55) for non-dense tissue and from 22.8 to 22.3% (p(trend) = 0.78) for relative density. Only among women who were younger than 10 years during the famine was the amount of non-dense tissue significantly lower with higher exposure, with 53.1 cm(2) for severely exposed compared to 77.8 cm(2) (p(trend) = 0.03) for unexposed. This group also appeared to have smaller breasts with more absolute and relative density, but not statistically significant. We observed no overall effect on breast density in women severely exposed to a short, intense caloric restriction. However, in women exposed before puberty, the non-dense area was smaller and density tended to be higher.

Hand hygiene compliance in Dutch general practice offices.

BACKGROUND: Hand hygiene (HH) is considered one of the most important measures to prevent healthcare-associated infections (HAI). Most studies focus on HH compliance within the hospital setting, whereas little is known for the outpatient setting. The aim of this study was to evaluate compliance with HH recommendations in general practitioners (GPs) office, based on World Health Organization (WHO) guideline. METHODS: An observational study was conducted at five Dutch GPs-practices in September 2017. We measured HH compliance through direct observation using WHO's 'five moments of hand hygiene' observation tool. All observations were done by one trained professional. RESULTS: We monitored a total of 285 HH opportunities for 30 health care workers (HCWs). The overall compliance was 37%. Hand hygiene compliance was 34, 51 and 16% for general practitioners, practice assistants, and nurses, respectively. It varies between 63% after body fluid exposure and no HH performance before-, during and after home visit of a patient (defined as moment 5). The preferred method of HH was soap and water (63%) versus 37% for alcohol-based hand rub (ABHR). The median time of disinfecting hands was 8 s (range 6-11 s) for HCWs in our study. CONCLUSIONS: HH compliance among HCWs in Dutch GPs was found to be low, especially with regard to home visits. The WHO recommended switch from hand wash to ABHR was not implemented by the majority of HCWs in 5 observed GPs offices.