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Infectious viral load (VL) expelled as droplets and aerosols by infected individuals partly determines transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). RNA VL measured by qRT-PCR is only a weak proxy for infectiousness. Studies on the kinetics of infectious VL are important to understand the mechanisms behind the different transmissibility of SARS-CoV-2 variants and the effect of vaccination on transmission, which allows guidance of public health measures. In this study, we quantified infectious VL in individuals infected with SARS-CoV-2 during the first five symptomatic days by in vitro culturability assay in unvaccinated or vaccinated individuals infected with pre-variant of concern (pre-VOC) SARS-CoV-2, Delta or Omicron BA.1. Unvaccinated individuals infected with pre-VOC SARS-CoV-2 had lower infectious VL than Delta-infected unvaccinated individuals. Full vaccination (defined as2 weeks after receipt of the second dose during the primary vaccination series) significantly reduced infectious VL for Delta breakthrough cases compared to unvaccinated individuals. For Omicron BA.1 breakthrough cases, reduced infectious VL was observed only in boosted but not in fully vaccinated individuals compared to unvaccinated individuals. In addition, infectious VL was lower in fully vaccinated Omicron BA.1 -infected individuals compared to fully vaccinated Delta-infected individuals, suggesting that mechanisms other than increased infectious VL contribute to the high infectiousness of SARS-CoV-2 Omicron BA.1 . Our findings indicate that vaccines may lower transmission risk and, therefore, have a public health benefit beyond the individual protection from severe disease.

Purpose Prisons can be epicentres of infectious diseases. However, empirical evidence on the impact of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic in prison is still scarce. This study aims to estimate the seroprevalence rates of anti-SARS-CoV-2 in the largest and most crowded Swiss prison and compare them with the seroprevalence rate in the general population. Design/methodology/approach A cross-sectional study was conducted in June 2020, one month after the first wave of SARS-CoV-2 in Switzerland. Groups included: people living in detention (PLDs) detained before the beginning of the pandemic (n = 116), PLDs incarcerated after the beginning of the pandemic (n = 61), prison staff and prison healthcare workers (n = 227) and a sample from the general population in the same time period (n = 3,404). The authors assessed anti-SARS-CoV-2 IgG antibodies. Findings PLDs who were incarcerated before the beginning of the pandemic had a significantly lower seroprevalence rate [0.9%, confidence interval (CI)95%: 0.1%–5.9%] compared to the general population (6.3%, CI 95%: 5.6–7.3%) (p = 0.041). The differences between PLDs who were incarcerated before and other groups were marginally significant (PLDs incarcerated after the beginning of the pandemic: 6.6%, CI 95%: 2.5%–16.6%, p = 0.063; prison staff CI 95%: 4.8%, 2.7%–8.6%, p = 0.093). The seroprevalence of prison staff was only slightly and non-significantly lower than that of the general population. Originality/value During the first wave, despite overcrowding and interaction with the community, the prison was not a hotspot of SARS-CoV-2 infection. Preventive measures probably helped avoiding clusters of infection. The authors suggest that preventive measures that impact social welfare could be relaxed when overall circulation in the community is low to prevent the negative impact of isolation.

Background:The dynamics of coronavirus disease 2019 (COVID-19) seroconversion of hospital employees are understudied. We measured the proportion of seroconverted employees and evaluated risk factors for seroconversion during the first pandemic wave.Methods:In this prospective cohort study, we recruited Geneva University Hospitals employees and sampled them 3 times, every 3 weeks from March 30 to June 12, 2020. We measured the proportion of seroconverted employees and determined prevalence ratios of risk factors for seroconversion using multivariate mixed-effects Poisson regression models.Results:Overall, 3,421 participants (29% of all employees) were included, with 92% follow-up. The proportion of seroconverted employees increased from 4.4% (95% confidence interval [CI], 3.7%–5.1%) at baseline to 8.5% [(95% CI, 7.6%–9.5%) at the last visit. The proportions of seroconverted employees working in COVID-19 geriatrics and rehabilitation (G&R) wards (32.3%) and non–COVID-19 G&R wards (12.3%) were higher compared to office workers (4.9%) at the last visit. Only nursing assistants had a significantly higher risk of seroconversion compared to office workers (11.7% vs 4.9%; P = .006). Significant risk factors for seroconversion included the use of public transportation (adjusted prevalence ratio, 1.59; 95% CI, 1.25–2.03), known community exposure to severe acute respiratory coronavirus virus 2 (2.80; 95% CI, 2.22–3.54), working in a ward with a nosocomial COVID outbreak (2.93; 95% CI, 2.27–3.79), and working in a COVID-19 G&R ward (3.47; 95% CI, 2.45–4.91) or a non–COVID-19 G&R ward (1.96; 95% CI, 1.46–2.63). We observed an association between reported use of respirators and lower risk of seroconversion (0.73; 95% CI, 0.55–0.96).Conclusion:Additional preventive measures should be implemented to protect employees in G&R wards. Randomized trials on the protective effect of respirators are urgently needed.

An examination of all coronavirus disease 2019 (COVID-19) cases and patient movements in Geneva indicated important disease activity within the healthcare system since the beginning of the pandemic. We estimate that 4.3% of all COVID-19 cases were likely acquired within the healthcare system, contributing to 62% of the COVID-19–related deaths.

The purpose of this study is to identify predictive factors associated with missed diagnosis of B. pertussis-B. holmesii co-infection by assessing the analytical performance of a commercially available multiplexed PCR assay and by building a prediction model based on clinical signs and symptoms for detecting co-infections. This is a retrospective study on the electronic health records of all clinical samples that tested positive to either B. pertussis or B. holmesii from January 2015 to January 2018 at Geneva University Hospitals. Multivariate logistic regression was used to build a model for co-infection prediction based on the electronic health record chart review. Limit of detection was determined for all targets of the commercial multiplexed PCR assay used on respiratory samples. A regression model, developed from clinical symptoms and signs, predicted B. pertussis and B. holmesii co-infection with an accuracy of 82.9% (95% CI 67.9-92.8%, p value = .012), for respiratory samples positive with any of the two tested Bordetella species. We found that the LOD of the PCR reaction targeting ptxS1 is higher than that reported by the manufacturer by a factor 10. The current testing strategy misses B. pertussis and B. holmesii co-infections by reporting only B. holmesii infections. Thus, we advocate to perform serological testing for detecting a response against pertussis toxin whenever a sample is found positive for B. holmesii. These findings are important, both from a clinical and epidemiological point of view, as the former impacts the choice of antimicrobial drugs and the latter biases surveillance data, by underestimating B. pertussis infections during co-infections.

Background Prehospital professionals such as emergency physicians or paramedics must be able to choose and adequately don and doff personal protective equipment (PPE) in order to avoid COVID-19 infection. Our aim was to evaluate the impact of a gamified e-learning module on adequacy of PPE in student paramedics. Methods This was a web-based, randomized 1:1, parallel-group, triple-blind controlled trial. Student paramedics from three Swiss schools were invited to participate. They were informed they would be presented with both an e-learning module and an abridged version of the current regional prehospital COVID-19 guidelines, albeit not in which order. After a set of 22 questions designed to assess baseline knowledge, the control group was shown the guidelines before answering a set of 14 post-intervention questions. The e-learning group was shown the gamified e-learning module right after the guidelines, and before answering post-intervention questions. The primary outcome was the difference in the percentage of adequate choices of PPE before and after the intervention. Results The participation rate was of 71% (98/138). A total of 90 answer sets was analyzed. Adequate choice of PPE increased significantly both in the control (50% [33;83] vs 25% [25;50], P = .013) and in the e-learning group (67% [50;83] vs 25% [25;50], P = .001) following the intervention. Though the median of the difference was higher in the e-learning group, there was no statistically significant superiority over the control (33% [0;58] vs 17% [− 17;42], P = .087). The e-learning module was of greatest benefit in the subgroup of student paramedics who were actively working in an ambulance company (42% [8;58] vs 25% [− 17;42], P = 0.021). There was no significant effect in student paramedics who were not actively working in an ambulance service (0% [− 25;33] vs 17% [− 8;50], P = .584). Conclusions The use of a gamified e-learning module increases the rate of adequate choice of PPE only among student paramedics actively working in an ambulance service. In this subgroup, combining this teaching modality with other interventions might help spare PPE and efficiently protect against COVID-19 infection.

BackgroundViral load (VL) is one determinant of secondary transmission of SARS-CoV-2. Emergence of variants of concerns (VOC) Alpha and Delta was ascribed, at least partly, to higher VL. Furthermore, with parts of the population vaccinated, knowledge on VL in vaccine-breakthrough infections is crucial. As RNA VL is only a weak proxy for infectiousness, studies on infectious virus presence by cell culture isolation are of importance.MethodsWe assessed nasopharyngeal swabs of COVID-19 patients for quantitative infectious viral titres (IVT) by focus-forming assay and compared to overall virus isolation success and RNA genome copies. We assessed IVTs during the first 5 symptomatic days in a total of 384 patients: unvaccinated individuals infected with pre-VOC SARS-CoV-2 (n= 118) or Delta (n= 127) and vaccine breakthrough infections with Delta (n= 121) or Omicron (n=18).FindingsCorrelation between RNA copy number and IVT was low for all groups. No correlation between IVTs and age or sex was seen. We observed higher RNA genome copies in pre-VOC SARS-CoV-2 compared to Delta, but significantly higher IVTs in Delta infected individuals. Vaccinated Delta infected individuals had significantly lower RNA genome copies and IVTs compared to unvaccinated subjects and cleared virus faster. In addition, vaccinated individuals with Omicron infection had comparable IVTs to Delta breakthrough infections.InterpretationQuantitative IVTs can give detailed insights into virus shedding kinetics. Vaccination was associated with lower infectious titres and faster clearance for Delta, showing that vaccination would also lower transmission risk. Omicron vaccine-breakthrough infections did not show elevated IVTs compared to Delta, suggesting that other mechanisms than increase VL contribute to the high infectiousness of Omicron.FundingThis work was supported by the Swiss National Science Foundation 196644, 196383, NRP (National Research Program) 78 Covid-19 Grant 198412, the Fondation Ancrage Bienfaisance du Groupe Pictet and the Fondation Privée des Hôpitaux Universitaires de Genève.

BackgroundThere is ongoing uncertainty regarding transmission chains and the respective roles of healthcare workers (HCWs) and elderly patients in nosocomial outbreaks of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in geriatric settings.MethodsWe performed a retrospective cohort study including patients with nosocomial coronavirus disease 2019 (COVID-19) in four outbreak-affected wards, and all SARS-CoV-2 RT-PCR positive HCWs from a Swiss university-affiliated geriatric acute-care hospital that admitted both Covid-19 and non-Covid-19 patients during the first pandemic wave in Spring 2020. We combined epidemiological and genetic sequencing data using a Bayesian modelling framework, and reconstructed transmission dynamics of SARS-CoV-2 involving patients and HCWs, in order to determine who infected whom. We evaluated general transmission patterns according to type of case (HCWs working in dedicated Covid-19 cohorting wards: HCWcovid; HCWs working in non-Covid-19 wards where outbreaks occurred: HCWoutbreak; patients with nosocomial Covid-19: patientnoso) by deriving the proportion of infections attributed to each type of case across all posterior trees and comparing them to random expectations.ResultsDuring the study period (March 1 to May 7, 2020) we included 180 SARS-CoV-2 positive cases: 127 HCWs (91 HCWcovid, 36 HCWoutbreak) and 53 patients. The attack rates ranged from 10-19% for patients, and 21% for HCWs. We estimated that there were 16 importation events (3 patients, 13 HCWs) that jointly led to 16 secondary cases. Most patient-to-patient transmission events involved patients having shared a ward (97.6%, 95% credible interval [CrI] 90.4-100%), in contrast to those having shared a room (44.4%, 95%CrI 27.8-62.5%). Transmission events tended to cluster by type of case: patientnosowere almost twice as likely to be infected by other patientnosothan expected (observed:expected ratio 1.91, 95%CrI 1.08 – 4.00,p= 0.02); similarly, HCWoutbreakwere more than twice as likely to be infected by other HCWoutbreakthan expected (2.25, 95%CrI 1.00-8.00,p= 0.04). The proportion of infectors of HCWcovidwere as expected as random. The proportions of high transmitters (≥2 secondary cases) were significantly higher among HCWoutbreakthan patientnosoin the late phases (26.2% vs. 13.4%, pConclusionsMost importation events were linked to HCW. Unexpectedly, transmission between HCWcovidwas more limited than transmission between patients and HCWoutbreak. This highlights gaps in infection control and suggests possible areas of improvements to limit the extent of nosocomial transmission.

Background Since 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. Aim This study compares in-hospital outcomes for patients with community-acquired COVID-19 and patients with community-acquired influenza in Switzerland. Methods This 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. Results In 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 Conclusion Community-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.

BackgroundWhen comparing the periods of time during and after the first wave of the ongoing SARS-CoV-2/COVID-19 pandemic in Europe, 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.MethodsWe investigated the trends in COVID-19 related mortality (in-hospital and in-intermediate/intensive-care) over time in Switzerland, from February 2020 to May 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.ResultsOur analysis included 16,030 episodes recorded in CH-SUR, with 2,320 reported deaths due to COVID-19 (13.0% of included episodes). We found that overall in-hospital mortality was lower during the second wave of COVID-19 compared to the first wave (HR 0.71, 95% CI 0.69 – 0.72, p-value < 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 to the first wave (HR 1.48, 95% CI 1.42 – 1.55, p-value < 0.001), with significant changes in the course of hospitalisation between the first and the second wave.ConclusionWe 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.

Background: Nosocomial outbreaks of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are frequent despite implementation of conventional infection control measures. We performed an outbreak investigation using advanced genomic and statistical techniques to reconstruct likely transmission chains and assess the role of healthcare workers (HCWs) in SARS-CoV-2 transmission. Methods: We investigated a nosocomial SARS-CoV-2 outbreak in a university-affiliated rehabilitation clinic, involving patients and HCWs, with high coverage of pathogen whole genome sequences (WGS). We estimated the time-varying reproduction number from epidemiological data (Rt) and produced a maximum likelihood phylogeny to assess genetic diversity of the pathogen. We combined genomic and epidemiological data into a Bayesian framework to model directionality of transmission. We performed a case-control study to investigate risk factors for nosocomial SARS-CoV-2 acquisition in patients. Findings: The outbreak spanned from March 14 to April 12, 2020 and involved 37 patients (31 with WGS) and 39 employees (31 with WGS) of whom 37 are HCWs. We estimated a peak Rt between 2·2 – 3·6. The phylogenetic tree showed very limited genetic diversity, with 60/62 (96·7%) isolates forming one large cluster of identical genomes. Despite the resulting uncertainty in reconstructed transmission events, our analyses suggest that HCWs (one of whom was the index case) played an essential role in cross-transmission, with a significantly larger fraction of infections (p 5: 82·3%; 95%CI 81·8% - 83·4%). Furthermore, frail patients were found to be at greater risk for nosocomial COVID-19 than other patients (adjusted OR 6·94; 95%CI 2·13 – 22·57). Interpretation: This outbreak report highlights the essential role of HCWs in SARS-CoV-2 transmission dynamics in healthcare settings. Limited genetic diversity in pathogen genomes hampered the reconstruction of individual transmission events, resulting in substantial uncertainty in who infected whom. However, our study shows that despite such uncertainty, significant transmission patterns can be observed. Funding: This work was supported by a grant from the Swiss National Science Foundation under the NRP78 Covid-19 funding scheme (Grant no. 4078P0_198363). Declaration of Interests: All authors have no conflicts of interest to declare. Ethics Approval Statement: Outbreak investigations are within the purview of the IPC programme. For additional investigations, the local Ethic Committee approved this study (no. 2020-01330).

BackgroundThe SARS-CoV-2 pandemic led to a steep increase in hospital and intensive care unit (ICU) admissions for acute respiratory failure worldwide. Early identification of patients at risk of clinical deterioration is crucial in terms of appropriate care delivery and resource allocation. We aimed to evaluate and compare the prognostic performance of Sequential Organ Failure Assessment (SOFA), Quick Sequential Organ Failure Assessment (qSOFA), Confusion, Uraemia, Respiratory Rate, Blood Pressure and Age ≥65 (CURB-65), Respiratory Rate and Oxygenation (ROX) index and Coronavirus Clinical Characterisation Consortium (4C) score to predict death and ICU admission among patients admitted to the hospital for acute COVID-19 infection.Methods and analysisConsecutive adult patients admitted to the Geneva University Hospitals during two successive COVID-19 flares in spring and autumn 2020 were included. Discriminative performance of these prediction rules, obtained during the first 24 hours of hospital admission, were computed to predict death or ICU admission. We further exluded patients with therapeutic limitations and reported areas under the curve (AUCs) for 30-day mortality and ICU admission in sensitivity analyses.ResultsA total of 2122 patients were included. 216 patients (10.2%) required ICU admission and 303 (14.3%) died within 30 days post admission. 4C score had the best discriminatory performance to predict 30-day mortality (AUC 0.82, 95% CI 0.80 to 0.85), compared with SOFA (AUC 0.75, 95% CI 0.72 to 0.78), qSOFA (AUC 0.59, 95% CI 0.56 to 0.62), CURB-65 (AUC 0.75, 95% CI 0.72 to 0.78) and ROX index (AUC 0.68, 95% CI 0.65 to 0.72). ROX index had the greatest discriminatory performance (AUC 0.79, 95% CI 0.76 to 0.83) to predict ICU admission compared with 4C score (AUC 0.62, 95% CI 0.59 to 0.66), CURB-65 (AUC 0.60, 95% CI 0.56 to 0.64), SOFA (AUC 0.74, 95% CI 0.71 to 0.77) and qSOFA (AUC 0.59, 95% CI 0.55 to 0.62).ConclusionScores including age and/or comorbidities (4C and CURB-65) have the best discriminatory performance to predict mortality among inpatients with COVID-19, while scores including quantitative assessment of hypoxaemia (SOFA and ROX index) perform best to predict ICU admission. Exclusion of patients with therapeutic limitations improved the discriminatory performance of prognostic scores relying on age and/or comorbidities to predict ICU admission.

BACKGROUND SARS-CoV-2/COVID-19, which emerged in China in late 2019, rapidly spread across the world with several million victims in 213 countries. Switzerland was severely hit by the virus, with 43,000 confirmed cases as of 1 September 2020. AIM In cooperation with the Federal Office of Public Health, we set up a surveillance database in February 2020 to monitor hospitalised patients with COVID-19, in addition to their mandatory reporting system. METHODS Patients hospitalised for more than 24 hours with a positive polymerase chain-reaction test, from 20 Swiss hospitals, are included. Data were collected in a customised case report form based on World Health Organisation recommendations and adapted to local needs. Nosocomial infections were defined as infections for which the onset of symptoms was more than 5 days after the patient’s admission date. RESULTS As of 1 September 2020, 3645 patients were included. Most patients were male (2168, 59.5%), and aged between 50 and 89 years (2778, 76.2%), with a median age of 68 (interquartile range 54–79). Community infections dominated with 3249 (89.0%) reports. Comorbidities were frequently reported, with hypertension (1481, 61.7%), cardiovascular diseases (948, 39.5%) and diabetes (660, 27.5%) being the most frequent in adults; respiratory diseases and asthma (4, 21.1%), haematological and oncological diseases (3, 15.8%) were the most frequent in children. Complications occurred in 2679 (73.4%) episodes, mostly respiratory diseases (2470, 93.2% in adults; 16, 55.2% in children), and renal (681, 25.7%) and cardiac (631, 23.8%) complications for adults. The second and third most frequent complications in children affected the digestive system and the liver (7, 24.1%). A targeted treatment was given in 1299 (35.6%) episodes, mostly with hydroxychloroquine (989, 76.1%). Intensive care units stays were reported in 578 (15.8%) episodes. A total of 527 (14.5%) deaths were registered, all among adults. CONCLUSION The surveillance system has been successfully initiated and provides a robust set of data for Switzerland by including about 80% (compared with official statistics) of SARS-CoV-2/COVID-19 hospitalised patients, with similar age and comorbidity distributions. It adds detailed information on the epidemiology, risk factors and clinical course of these cases and, therefore, is a valuable addition to the existing mandatory reporting.

BackgroundSARS-CoV-2/COVID-19, which emerged in China in late 2019, rapidly spread across the world causing several million victims in 213 countries. Switzerland was severely hit by the virus, with 43’000 confirmed cases as of September 1st, 2020.AimIn cooperation with the Federal Office of Public Health, we set up a surveillance database in February 2020 to monitor hospitalised patients with COVID-19 in addition to their mandatory reporting system.MethodsPatients hospitalised for more than 24 hours with a positive PCR test, from 20 Swiss hospitals, are included. Data collection follows a custom Case Report Form based on WHO recommendations and adapted to local needs. Nosocomial infections were defined as infections for which the onset of symptoms started more than 5 days after the patient’s admission date.ResultsAs of September 1st, 2020, 3645 patients were included. Most patients were male (2168 - 59.5%),and aged between 50 and 89 years (2778 - 76.2%), with a median age of 68 (IQR 54-79). Community infections dominated with 3249 (89.0%) reports. Comorbidities were frequently reported: hypertension (1481 - 61.7%), cardiovascular diseases (948 - 39.5%), and diabetes (660 - 27.5%) being the most frequent in adults; respiratory diseases and asthma (4 −21.1%), haematological and oncological diseases (3 – 15.8%) being the most frequent in children. Complications occurred in 2679 (73.4%) episodes, mostly for respiratory diseases (2470 - 93.2% in adults, 16 – 55.2% in children), renal (681 – 25.7%) and cardiac (631 – 23.8%) complication for adults. The second and third most frequent complications in children affected the digestive system and the liver (7 - 24.1%). A targeted treatment was given in 1299 (35.6%) episodes, mostly with hydroxychloroquine (989 - 76.1%). Intensive care units stays were reported in 578 (15.8%) episodes. 527 (14.5%) deaths were registered, all among adults.ConclusionThe surveillance system has been successfully initiated and provides a very representative set of data for Switzerland. We therefore consider it to be a valuable addition to the existing mandatory reporting, providing more precise information on the epidemiology, risk factors, and clinical course of these cases.

Background Patients on maintenance hemodialysis are at high risk for serious complications from COVID-19 infection including death. We present an overview of the local experience with dialysis units management and reorganization, local epidemiology and outcomes during the COVID-19 outbreak in Geneva, Switzerland.Methods All SARS-CoV-2 positive outpatients on maintenance dialysis were transferred from their usual dialysis facility to the Geneva University Hospitals dialysis unit to avoid creation of new clusters of transmission. Within this unit, appropriate mitigation measures were enforced as suggested by the institutional team for prevention and control of infectious diseases.Results From February 25 to May 18, 2020, 19 of 246 patients on maintenance dialysis were tested positive for SARS-CoV-2, representing an incidence rate of 97.6 cases per 100,000 person-days. Eighteen patients were on maintenance hemodialysis and one on peritoneal dialysis. Twelve of these infections were detected during the first two weeks after mitigation strategies were enforced. Most common symptoms were fever (89%), cough (84%) and fatigue (68%). Two patients required orotracheal intubation. Six patients on maintenance hemodialysis who had previously tested positive for SARS-CoV-2, all of them male, died (32%). Five deaths were COVID-19 related and one death was due to dialysis withdrawal at the patient’s request. Conclusion Strict mitigation measures seemed to be effective to control infection spread among patients on maintenance dialysis. COVID-19 infection is associated with a high fatality rate. Large scale epidemiological studies are needed to assess the efficacy of preventive measures in decreasing infection and mortality rate within the dialysis population.

Summary Background In Switzerland each year, influenza leads to between 112,000 and 275,000 medical consultations. Data on nosocomial influenza infection are limited. Aim To describe nosocomial cases of seasonal influenza in south-western Switzerland. Methods This study was conducted during two seasonal influenza epidemics from 2016 to 2018 in 27 acute care public hospitals in south-western Switzerland. During these two time-periods, every patient hospitalized for >72 h who was positively screened by reverse transcription–polymerase chain reaction or antigen detection for influenza was included in the survey. Characteristics of patients included age, sex, and comorbidities. Included patients were followed up until discharge or death. Complications and administration of antineuraminidases and/or antibiotics were registered. Findings The median influenza vaccine coverage of healthcare workers was 40%. In all, 836 patients were included (98% with type A influenza virus in 2016–2017; 77% with type B virus in 2017–2018). Most patients (81%) had an unknown vaccine status. Overall, the incidence of nosocomial influenza was 0.5 per 100 admissions (0.35 per 1000 patient-days). The most frequent comorbidities were diabetes (20%), chronic respiratory diseases (19%), and malnutrition (17%). Fever (77%) and cough (66%) were the most frequent symptoms. Seventy-one percent of patients received antineuraminidases, 28% received antibiotics. Infectious complications such as pneumonia were reported in 9%. Overall, the all-cause mortality was 6%. Conclusion The occurrence of nosocomial influenza underlines the importance of vaccinating patients and healthcare workers, rapidly recognizing community- or hospital-acquired cases, and applying adequate additional measures to prevent dissemination, including the timely administration of antineuraminidases to avoid antibiotic use (and misuse).

BACKGROUND To avoid misuse of personal protective equipment (PPE), ensure health care workers’ safety, and avoid shortages, effective communication of up-to-date infection control guidelines is essential. As prehospital teams are particularly at risk of contamination given their challenging work environment, a specific gamified electronic learning (e-learning) module targeting this audience might provide significant advantages as it requires neither the presence of learners nor the repetitive use of equipment for demonstration. OBJECTIVE The aim of this study was to evaluate whether a gamified e-learning module could improve the rate of adequate PPE choice by prehospital personnel in the context of the coronavirus disease (COVID-19) pandemic. METHODS This was an individual-level randomized, controlled, quadruple-blind (investigators, participants, outcome assessors, and data analysts) closed web-based trial. All emergency prehospital personnel working in Geneva, Switzerland, were eligible for inclusion, and were invited to participate by email in April 2020. Participants were informed that the study aim was to assess their knowledge regarding PPE, and that they would be presented with both the guidelines and the e-learning module, though they were unaware that there were two different study paths. All participants first answered a preintervention quiz designed to establish their profile and baseline knowledge. The control group then accessed the guidelines before answering a second set of questions, and were then granted access to the e-learning module. The e-learning group was shown the e-learning module right after the guidelines and before answering the second set of questions. RESULTS Of the 291 randomized participants, 176 (60.5%) completed the trial. There was no significant difference in baseline knowledge between groups. Though the baseline proportion of adequate PPE choice was high (75%, IQR 50%-75%), participants’ description of the donning sequence was in most cases incorrect. After either intervention, adequate choice of PPE increased significantly in both groups (PP=.27). Confidence in the ability to use PPE was maintained in the e-learning group (P=.27) but significantly decreased in the control group (P=.04). CONCLUSIONS Among prehospital personnel with an already relatively high knowledge of and experience with PPE use, both web-based study paths increased the rate of adequate choice of PPE. There was no major added value of the gamified e-learning module apart from preserving participants' confidence in their ability to correctly use PPE.

BACKGROUND The coronavirus disease (COVID-19) pandemic has led to increased use of personal protective equipment (PPE). Adequate use of this equipment is more critical than ever because the risk of shortages must be balanced against the need to effectively protect health care workers, including prehospital personnel. Specific training is therefore necessary; however, the need for social distancing has markedly disrupted the delivery of continuing education courses. Electronic learning (e-learning) may provide significant advantages because it requires neither the physical presence of learners nor the repetitive use of equipment for demonstration. OBJECTIVE Inclusion of game mechanics, or “gamification,” has been shown to increase knowledge and skill acquisition. The objective of this research was to develop a gamified e-learning module to interactively deliver concepts and information regarding the correct choice and handling of PPE. METHODS The SERES framework was used to define and describe the development process, including scientific and design foundations. After we defined the target audience and learning objectives by interviewing the stakeholders, we searched the scientific literature to establish relevant theoretical bases. The learning contents were validated by infection control and prehospital experts. Learning mechanics were then determined according to the learning objectives, and the content that could benefit from the inclusion of game mechanics was identified. RESULTS The literature search resulted in the selection and inclusion of 12 articles. In addition to gamification, pretesting, feedback, avoiding content skipping, and demonstrations using embedded videos were used as learning mechanics. Gamification was used to enhance the interactivity of the PPE donning and doffing sequences, which presented the greatest learning challenges. The module was developed with Articulate Storyline 3 to ensure that it would be compatible with a wide array of devices, as this software generates HTML5-compatible output that can be accessed on smartphones, tablets, and regular computers as long as a recent browser is available. CONCLUSIONS A gamified e-learning module designed to promote better knowledge and understanding of PPE use among prehospital health care workers was created by following the SERES framework. The impact of this module should now be assessed by means of a randomized controlled trial.

Influenza was recently reported as a risk factor for invasive aspergillosis (IA). We aimed to describe prognostic factors for influenza-associated IA (IAA) and poor outcome and mortality in critically ill patients in Switzerland. All adults with confirmed influenza admitted to the ICU at two Swiss tertiary care centres during the 2017/2018 influenza season were retrospectively evaluated. IAA was defined by clinical, mycological and radiological criteria: a positive galactomannan in bronchoalveolar lavage or histopathological or cultural evidence in respiratory specimens of Aspergillus spp., any radiological infiltrate and a compatible clinical presentation. Poor outcome was defined as a composite of in-hospital mortality, ICU length of stay (LOS), invasive ventilation for > 7 days or extracorporeal membrane oxygenation. Of 81 patients with influenza in the ICU, 9 (11%) were diagnosed with IAA. All patients with IAA had poor outcome compared to 26 (36%) patients without IAA (p < 0.001). Median ICU-LOS and mortality were 17 vs. 3 days (p < 0.01) and 3/9 (33%) vs. 13/72 (18%; p = 0.37) in patients with vs. without IAA, respectively. Patients with IAA had significantly longer durations of antibiotic therapy, vasoactive support and mechanical ventilation. Aspergillus was the most common respiratory co-pathogen (9/40, 22%) followed by classical bacterial co-pathogens. IAA was not associated with classical risk factors. Aspergillus is a common superinfection in critically ill influenza patients associated with poor outcome and longer duration of organ supportive therapies. Given the absence of classical risk factors for aspergillosis, greater awareness is necessary, particularly in those requiring organ supportive therapies. Electronic supplementary material The online version of this article (10.1007/s10096-020-03923-7) contains supplementary material, which is available to authorized users.

Background The coronavirus disease (COVID-19) pandemic has led to increased use of personal protective equipment (PPE). Adequate use of this equipment is more critical than ever because the risk of shortages must be balanced against the need to effectively protect health care workers, including prehospital personnel. Specific training is therefore necessary; however, the need for social distancing has markedly disrupted the delivery of continuing education courses. Electronic learning (e-learning) may provide significant advantages because it requires neither the physical presence of learners nor the repetitive use of equipment for demonstration. Objective Inclusion of game mechanics, or “gamification,” has been shown to increase knowledge and skill acquisition. The objective of this research was to develop a gamified e-learning module to interactively deliver concepts and information regarding the correct choice and handling of PPE. Methods The SERES framework was used to define and describe the development process, including scientific and design foundations. After we defined the target audience and learning objectives by interviewing the stakeholders, we searched the scientific literature to establish relevant theoretical bases. The learning contents were validated by infection control and prehospital experts. Learning mechanics were then determined according to the learning objectives, and the content that could benefit from the inclusion of game mechanics was identified. Results The literature search resulted in the selection and inclusion of 12 articles. In addition to gamification, pretesting, feedback, avoiding content skipping, and demonstrations using embedded videos were used as learning mechanics. Gamification was used to enhance the interactivity of the PPE donning and doffing sequences, which presented the greatest learning challenges. The module was developed with Articulate Storyline 3 to ensure that it would be compatible with a wide array of devices, as this software generates HTML5-compatible output that can be accessed on smartphones, tablets, and regular computers as long as a recent browser is available. Conclusions A gamified e-learning module designed to promote better knowledge and understanding of PPE use among prehospital health care workers was created by following the SERES framework. The impact of this module should now be assessed by means of a randomized controlled trial.

BACKGROUND: Patients on maintenance dialysis are at high risk for serious complications from COVID-19 infection, including death. We present an overview of local experience with dialysis unit management and reorganisation, local epidemiology and outcomes during the COVID-19 outbreak in Geneva, Switzerland, where SARS-CoV-2 incidence was one of the highest in Europe. METHODS: All SARS-CoV-2-positive outpatients on maintenance dialysis were transferred from their usual dialysis facility to the Geneva University Hospitals dialysis unit to avoid creation of new clusters of transmission. Within this unit, appropriate mitigation measures were enforced, as suggested by the institutional team for prevention and control of infectious diseases. RESULTS: From 25 February to 31 December 2020, 82 of 279 patients on maintenance dialysis tested positive for SARS-CoV-2 during two distinct waves, with an incidence rate of 73 cases per 100,000 person-days during the first wave and 342 cases per 100,000 during the second wave, approximately four- to six-fold higher than the general population. The majority of infections (55%) during both waves were traced to clusters. Most infections (62%) occurred in men. Sixteen patients (34%) died from COVID-19 related complications. Deceased patients were older and had a lower body mass index as compared with patients who survived the infection. CONCLUSION: SARS-CoV-2 is associated with high infection and fatality rates in the dialysis population. Strict mitigation measures seemed to be effective in controlling infection spread among patients on maintenance dialysis outside of clusters. Large scale epidemiological studies are needed to assess the efficacy of preventive measures in decreasing infection and mortality rates within the dialysis population.

Nosocomial influenza increases morbidity and mortality in hospitalised patients. No multicentre study analysed its impact in Swiss hospitals yet. This study was conducted From November 1st to April 30th in 2016-2017 and 2017-2018 in 27 acute-care public hospitals in South-western Switzerland. It aimed at describing nosocomial cases of seasonal influenza. During these 2 time-periods, every patient hospitalized for >72 hours that was positively screened by RT-PCR or antigen detection for influenza was retrospectively included in the survey. Policies to prevent influenza were collected in each participating hospital. Characteristics of patients included age, sex, and comorbidities. Included patients were followed-up until discharge or death. Complications and administration of anti-neuraminidases and/or antibiotics were registered. The mean influenza vaccine coverage of healthcare workers (HCW) was 40%. 836 patients were included (98% with a type A influenza virus in 2016-2017; 77% with a type B virus in 2017-2018). Most patients (81%) had an unknown vaccine status. Overall, the incidence of nosocomial influenza was 0.3/100 admissions (0.35/1000 patient-days). The most frequent comorbidities were diabetes (21%), chronic respiratory diseases (18%), and malnutrition (17%). Fever (77%) and cough (66%) were the most frequent symptoms. 70% of patients received anti-neuraminidases, 28% received antibiotics. Infectious complications such as pneumonia were reported in 8%. Overall, the all-cause mortality was 6%. The occurrence of nosocomial influenza underlines the importance of vaccinating patients and HCW, rapidly recognising community or hospital-acquired cases, and applying adequate additional measures to prevent dissemination, including the timely administration of anti-neuraminidases to avoid antibiotic use (and misuse). Key messages Important to encourage patients to be vaccinated against influenza. Apply additional measures in order to prevent influenza dissemination.

The Swiss 2019 immunization schedule published includes 7 news clauses: 1) DTPa-IPV-Hib-HBV vaccination in newborns with the simplified dosing schedule "2+1"; 2) recommendation for vaccination against measles, mumps and rubella administered at 9 and 12 months of age; 3) pneumococcal immunization in children under 5 years of age as a basic recommendation; 4) replacement of the monovalent capsular group C meningococcal conjugate vaccine by the quadrivalent ACWY conjugate vaccine (Menveo); 5) extension of vaccination against tick-borne encephalitis virus to the entire Swiss territory - with the exception of the cantons of Geneva and Tessin - in people with risk factors for contagion; 6) replacement of Gardasil® with Gardasil 9® since January 2019; 7) recommendation for vaccination against hepatitis B in newborns.Le Plan de vaccination 2019 comprend sept nouveautés: 1) la vaccination DTPa-IPV-Hib-HBV chez le nourrisson avec le schéma simplifié à « 2+1 » doses; 2) la recommandation de la vaccination contre la rougeole, les oreillons et la rubéole (ROR) à 9 et 12 mois; 3) la vaccination contre les pneumocoques chez les enfants de moins de 5 ans comme recommandation de base; 4) le remplacement du vaccin conjugué monovalent contre le méningocoque C par le vaccin conjugué quadrivalent ACWY (

Le Plan de vaccination 2019 comprend sept nouveautés: 1) la vaccination DTPa-IPV-Hib-HBV chez le nourrisson avec le schéma simplifié à « 2+1 » doses; 2) la recommandation de la vaccination contre la rougeole, les oreillons et la rubéole (ROR) à 9 et 12 mois; 3) la vaccination contre les pneumocoques chez les enfants de moins de 5 ans comme recommandation de base; 4) le remplacement du vaccin conjugué monovalent contre le méningocoque C par le vaccin conjugué quadrivalent ACWY (Menveo); 5) l'élargissement de la vaccination contre l'encéphalite à tique verno-estivale (FSME) à tout le territoire suisse, à l'exception des cantons de Genève et du Tessin, chez les sujets présentant un facteur de risque d'exposition; 6) le remplacement de Gardasil par Gardasil 9 depuis janvier 2019 et 7) la recommandation de la vaccination contre l'hépatite B pour les nourrissons.

Background To avoid misuse of personal protective equipment (PPE), ensure health care workers’ safety, and avoid shortages, effective communication of up-to-date infection control guidelines is essential. As prehospital teams are particularly at risk of contamination given their challenging work environment, a specific gamified electronic learning (e-learning) module targeting this audience might provide significant advantages as it requires neither the presence of learners nor the repetitive use of equipment for demonstration. Objective The aim of this study was to evaluate whether a gamified e-learning module could improve the rate of adequate PPE choice by prehospital personnel in the context of the coronavirus disease (COVID-19) pandemic. Methods This was an individual-level randomized, controlled, quadruple-blind (investigators, participants, outcome assessors, and data analysts) closed web-based trial. All emergency prehospital personnel working in Geneva, Switzerland, were eligible for inclusion, and were invited to participate by email in April 2020. Participants were informed that the study aim was to assess their knowledge regarding PPE, and that they would be presented with both the guidelines and the e-learning module, though they were unaware that there were two different study paths. All participants first answered a preintervention quiz designed to establish their profile and baseline knowledge. The control group then accessed the guidelines before answering a second set of questions, and were then granted access to the e-learning module. The e-learning group was shown the e-learning module right after the guidelines and before answering the second set of questions. Results Of the 291 randomized participants, 176 (60.5%) completed the trial. There was no significant difference in baseline knowledge between groups. Though the baseline proportion of adequate PPE choice was high (75%, IQR 50%-75%), participants’ description of the donning sequence was in most cases incorrect. After either intervention, adequate choice of PPE increased significantly in both groups (P Conclusions Among prehospital personnel with an already relatively high knowledge of and experience with PPE use, both web-based study paths increased the rate of adequate choice of PPE. There was no major added value of the gamified e-learning module apart from preserving participants' confidence in their ability to correctly use PPE.

Preventing an influenza outbreak in an acute care requires a multimodal intervention, taking into account the actors involved (influenza virus, staff, patients, visitors), and the stage of the epidemic. Different means are used for this purpose : immunization, use of alcohol-based hand rub, identification of influenza cases, wearing of medical masks, social distance, and antiviral treatment. In addition, an epidemiological surveillance of influenza cases, in the general population and within the health facilities, must be associated.Prévenir l’éclosion de cas de grippe en milieu de soins aigus nécessite une intervention multimodale, qui tienne compte des acteurs en présence (le virus influenza, le personnel, les patients, les visiteurs) et du stade de l’épidémie. Différents moyens sont utilisés dans cet objectif : la vaccination, la friction des mains avec la solution hydro-alcoolique, l’identification des cas de grippe, le port du masque médical, la distance sociale et le traitement antiviral. A cela, il faut ajouter la surveillance épidémiologique des cas de grippe dans la population générale et dans l’institution de soins.

Preventing an influenza outbreak in an acute care requires a multimodal intervention, taking into account the actors involved (influenza virus, staff, patients, visitors), and the stage of the epidemic. Different means are used for this purpose : immunization, use of alcohol-based hand rub, identification of influenza cases, wearing of medical masks, social distance, and antiviral treatment. In addition, an epidemiological surveillance of influenza cases, in the general population and within the health facilities, must be associated.

Objectives To investigate a nosocomial outbreak of influenza. Design Prospective outbreak investigation with active case finding and molecular typing. Setting A large academic geriatric hospital in Switzerland. Participants Elderly hospitalized adults. Measurements Based on syndromic surveillance, a nosocomial influenza outbreak was suspected in February 2012. All suspected cases were screened for respiratory viruses using real-time reverse transcription polymerase chain reaction of nasopharyngeal swabs. Infection control procedures (droplet precautions with single room isolation whenever possible) were implemented for all suspected or confirmed cases. Specimens positive for influenza viruses were processed and sequenced whenever possible to track transmission dynamics. Results Respiratory samples from 155 suspected cases were analyzed during the outbreak period, of which 69 (44%) were positive for influenza virus, 26 (17%) were positive for other respiratory viruses, and 60 (39%) were negative. Three other cases fulfilled clinical criteria for influenza infection but were not sampled, and one individual was admitted with an already positive test, resulting in a total of 73 influenza cases, of which 62 (85%) were classified as nosocomial. Five distinct clusters of nosocomial transmission were identified using viral sequencing, with epidemiologically unexpected in-hospital transmission dynamics. Seven of 23 patients who experienced influenza complications died. Sixteen healthcare workers experienced an influenza-like illness (overall vaccination rate, 36%). Conclusion Nosocomial influenza transmission caused more secondary cases than repeated community importation during this polyclonal outbreak. Molecular tools revealed complex transmission dynamics. Low healthcare worker vaccination rates and gaps in recommended infection control procedures are likely to have contributed to nosocomial spread of influenza, which remains a potentially life-threatening disease in elderly adults.

Summary Background A detailed description of viral kinetics, duration of virus shedding, and intraviral evolution in different body sites is warranted to understand Ebola virus pathogenesis. Patients with Ebola virus infections admitted to university hospitals provide a unique opportunity to do such in-depth virological investigations. We describe the clinical, biological, and virological follow-up of a case of Ebola virus disease. Methods A 43-year-old medical doctor who contracted an Ebola virus infection in Sierra Leone on Nov 16, 2014 (day 1), was airlifted to Geneva University Hospitals, Geneva, Switzerland, on day 5 after disease onset. The patient received an experimental antiviral treatment of monoclonal antibodies (ZMAb) and favipiravir. We monitored daily viral load kinetics, estimated viral clearance, calculated the half-life of the virus in plasma, and analysed the viral genome via high-throughput sequencing, in addition to clinical and biological signs. Findings The patient recovered rapidly, despite an initial high viral load (about 1 × 10 7 RNA copies per mL 24 h after onset of fever). We noted a two-phase viral decay. The virus half-life decreased from about 26 h to 9·5 h after the experimental antiviral treatment. Compared with a consensus sequence of June 18, 2014, the isolate that infected this patient displayed only five synonymous nucleotide substitutions on the full genome (4901A→C, 7837C→T, 8712A→G, 9947T→C, 16201T→C) despite 5 months of human-to-human transmission. Interpretation This study emphasises the importance of virological investigations to fully understand the course of Ebola virus disease and adaptation of the virus. Whether the viral decay was caused by the effects of the immune response alone, an additional benefit from the antiviral treatment, or a combination of both is unclear. In-depth virological analysis and randomised controlled trials are needed before any conclusion on the potential effect of antiviral treatment can be drawn. Funding Geneva University Hospitals, Swiss Office of Public Health, Swiss Agency for Development and Cooperation, and Swiss National Science Foundation.

Fever is routinely faced during medical practice. Although it is part of the immune response against pathogens, it is often seen as deleterious and a source of discomfort leading to the use of antipyretic drugs. However, few clinical data support this common practice. On the contrary, to date, results tilt in favor of the beneficial effect of fever, such as a better immune response and inhibition of pathogen growth. Data encourage the treatment of fever only in certain conditions such as neurological symptoms, cardio-pulmonary failure, or fever of non-infectious origin. In fact recent evidence stress that systematic treatment of fever do not improve, but nor deteriorate, the disease outcome. This suggests to only treat the poorly tolerated fevers.L’état fébrile (EF) fait partie intégrante de la réponse immune contre les pathogènes, mais il est généralement considéré comme délétère et source d’inconfort, d’où l’usage fréquent d’antipyrétiques. Très peu de données cliniques encouragent cette pratique. A ce jour, certaines études plaident pour les bénéfices de l’EF, à savoir une réponse immune améliorée et une croissance des pathogènes inhibée. Certains auteurs recommandent donc le traitement de l’EF uniquement dans des situations particulières, comme une atteinte neurologique ou cardiopulmonaire ou lors d’un EF d’origine non infectieuse. Les données disponibles soulignent que le traitement systématique de l’EF n’améliore pas l’évolution de la maladie, sans toutefois l’aggraver non plus, et plaident pour ne traiter que les EF mal tolérés.

Background The Swiss Sentinel system for influenza virus surveillance reports influenza-like illness in the community through a network of primary care practitioners, but the epidemiologic, demographic, and virological characterization may differ from that observed in hospitalized patients with influenza. Objective To compare demographic and virological data from hospital influenza cases with Sentinel system data during the 2014–2015 season. Methods We included 2623 in- and outpatients with a screening request for influenza A/B in a university teaching hospital in Geneva, Switzerland, and 933 participants from the Swiss Sentinel surveillance system and compared the demographic and virological data of the two populations, including the respective distribution of influenza subtypes, and conducted a phylogenetic comparison at the HA1 level of influenza viruses recovered in community and hospital cases. Results There were similar proportions of influenza strains recovered in the hospital and in the community (H3N2, 57.1% and 56.9%; H1N1pdm09, 15.5% and 14.2%; B, 27.4% and 28.8%, respectively). HA1 sequence analysis confirmed that all three strains were genetically similar between the two populations. During this particular season, influenza cases were detected earlier in the hospital than in the Sentinel system. Conclusions Although an influenza surveillance system based on the community can predict the type of influenza strains that will be associated with hospitalizations, it fails to estimate the potential virulence of circulating strains. Further, the population characteristics in the community differ from those in hospitalized patients. This suggests that any national influenza surveillance system should include both community- and hospital-based surveys.

The International Consortium for Prevention and Infection Control (ICPIC) organises a biannual conference (ICPIC) on various subjects related to infection prevention, treatment and control. During ICPIC 2015, held in Geneva in June 2015, a full one-day session focused on the 2014–2015 Ebola virus disease (EVD) outbreak in West Africa. This article is a non-exhaustive compilation of these discussions. It concentrates on lessons learned and imagining a way forward for the communities most affected by the epidemic. The reader can access video recordings of all lectures delivered during this one-day session, as referenced. Topics include the timeline of the international response, linkages between the dynamics of the epidemic and infection prevention and control, the importance of community engagement, and updates on virology, diagnosis, treatment and vaccination issues. The paper also includes discussions from public health, infectious diseases, critical care and infection control experts who cared for patients with EVD in Africa, in Europe, and in the United Sates and were involved in Ebola preparedness in both high- and low-resource settings and countries. This review concludes that too little is known about the pathogenesis and treatment of EVD, therefore basic and applied research in this area are urgently required. Furthermore, it is clear that epidemic preparedness needs to improve globally, in particular through the strengthening of health systems at local and national levels. There is a strong need for culturally sensitive approaches to public health which could be designed and delivered by social scientists and medical professionals working together. As of December 2015, this epidemic killed more than 11,000 people and infected more than 28,000; it has also generated more than 17,000 survivors and orphans, many of whom face somatic and psychological complications. The continued treatment and rehabilitation of these people is a public health priority, which also requires an integration of specific medical and social science approaches, not always available in West Africa.

Vaccination of HCW against seasonal influenza (SI) is the cornerstone for the prevention of NOSO I. In countries where vaccination cannot be made mandatory by law, an alternative exists: HCWs’ obligation to be vaccinated (VAC) or to wear a mask during SI epidemics. This is the strategy (called “Zoning”) adopted by HUG since 2009. In Switzerland, in winters 2013/14 & 2014/15, SI had similar epidemic curves but vaccine effectiveness differed. In 2014/15, the trivalent vaccine did not cover the major circulating SI H3N2 strain.