Cell specific pro- and antiinflammatory lipidmediator shift in critically ill Covid19 patients

Introduction The COVID-19 pandemic had a significant impact on morbidity and mortality in Germany challenging intensive care unit (ICU) capacities across the country. To delineate the high variability in disease severity, clinical presentation and outcome, we focused on cellular regulators of inflammation and resolution on a single cell level to gain a deeper understanding of the patient's individual inflammatory response and their impact on survival. Methods Written informed consent was obtained from all patients and healthy controls. The study was approved by the local ethical review board (Az249/20 S-EB). To characterize the peripheral immune landscape, we performed a 14 parameter flow cytometric analysis of PBMCs of 32 critically ill CoV2 patients and a targeted HPLC-MS/MS of previously sorted PBMCs. All data was analyzed and correlated to clinical parameters and patients' outcomes (Fig. 4). Results As known [1], computational analysis of flow cytometry revealed a strong decrease of B Cell and CD8+ T Cell ratios and an increase of monocytes in critically ill CoV19 patients compared to control (Fig. 1A). Interestingly, non-survivors displayed an increased ratio of CD16+ monocytes and proinflammatory IL- 1beta in monocytes, B and T cells, while HLADR receptors were downregulated correlating with clinical outcome (Fig. 1B). Not unexpectedly, we saw a major increase in proinflammatory lipidmediators, such as PGJ2, PGF2, TxB2 (Fig. 1C). Additionally, our analysis revealed that not only the amount, but also the source of those mediators was shifted from CD16 to classical CD14 monocytes, even more pronounced in non-survivors. CD16 monocytes of CoV2 patients, however, lost the ability to generate proresolving lipidmediators depending on cytochrome p450 (Cyp450) or soluble epoxide hydrolase (sEH) TxB2 (Fig. 1D). Conclusions Even though a lot of insight into CoV2 has been gained over the last 2 years, relatively little is known about the impact of immune changes in critically ill patients. With this study, we are the first to attribute lipid mediators to specific cell types. Our findings show that TxB2 in critically ill CoV2 patients, which correlates with mortality in CoV2 [2], is produced mainly in CD14 monocytes. We further report that specifically non-survivors display increased ratios of non-classical CD16 monocytes, which are impaired to generate a major class of lipidmediators depending on Cyp450. In conclusion, these data provide evidence that not only the absolute amount of pro- and anti-inflammatory mediators, but also the cellular source of these mediators remains key to fully understand their role in critically ill CoV2 patients. (Figure Presented).

Immunological characterization of COVID-19 endotypes of critically ill patients

Introduction Over the last 20 months Sars-CoV-2 research revealed tremendous insights into the pathophysiology resulting in vaccines and first immunomodulatory therapies in an unprecedented short time [1]. However, the patient's individual clinical course is remarkably heterogenous and the effectivity of immunomo-dulatory therapies especially in critically ill patients is still very variable [2]. Therefore,a better understanding of the patients' individual immune response is needed [3]. Methods Unbiased machine learning grouped 323 Covid-19 patients treated at the Klinikum Rechts der Isar ICU into 3 different clusters. For this we queried the ICU electronic files and analyzed relevant clinical features (Fig. 1+2). To delineate biological differences within these clusters, we applied a 14 parameter flow cytometric panel to PBMCs from 27 of these CoV2 ICU patients. Flow data was analyzed using FlowJo and the FlowSOM package for unsupervised clustering (Fig. 3+4). Written informed consent was obtained from all patients and healthy controls. The study was approved by the local ethical review board (Az249/20 S-EB). Results Patients from cluster 1 had above ICU average respiratory function (Fig. 2), reduced liver function and received lower dose catecholamines. Immunologically these patients had significantly higher amount of CD3+CD4+ T helper cells (Fig. 5). Whilst B cell numbers were reduced, they were highly activated (HLA-DR-ordf). Activated monocytes produced high amounts of TNFa. Interestingly, proinflammatory CD14+ HLA-DRlow monocytes were not increased. Cluster 2 contains patients with renal impairment, an increased tendency for bacterial infection and elevated blood lactate levels. Cluster 3 is made up of long-term ICU patients with severely reduced respiratory function and high ECMO-dependency (Fig. 1). These patients had significantly increased ratios of activated innate immune cells. We have detected elevated levels of an interesting population of CD14+ HLA-DRlow monocytes, a well-established player of immune suppression [4], while cytotoxic T cells and B cells were found to be significantly reduced. Conclusion These data provided evidence that clinically defined endotypes of critically ill Covid-19 patients exhibit a distinct immune profile. The immunological differences support our theory that these endotypes might require personalized immunomodulatory therapies to restore the pro-regenerative cell function in ICU Covid-19 populations and improve patient outcome in the future.

Immune phenotypes correlate with the outcome of severe Covid-19 infection

Despite the tremendous impact of the Sars-CoV-2 global pandemic and becoming focus of scientific research[1], many aspects of the disease and its pathophysiology, especially concerning prognostic parameters and treatments remain uncertain. The aim of our study is to assess and link immune profiles of the dysregulated cellular immune response in patients hospitalized with severe Covid-19 to their outcomes. Therefore, we immune phenotyped severly ill Sars-CoV-2 patients on our ICU and to surviving to non-surviving patients and healthy controls. Methods Using flow cytometry (BD-Fortessa), we created a 14-parameter immunoprofile of 25 Covid-19 patients from our ICU and 11 of healthy control individuals. The analysis was based on live/dead control, CD3, CD4, CD8, CD19, CD66b, CD14, CD16, IL-10, TNF-α, IL-1β, HLA-DR and IL-6 antibodies. Both clusters (survivors, n=16;non-survivors, n=9) and healthy controls (n=11) were compared with each other by Kruskal-Wallis test with Dunns-Ls post-test correction for multiple testing (Prism V.9.0). The patients in both groups had a similar age and at the time of analysis (Fig. 1A), the treatment was insignificantly more invasive in non-survivors than in survivors (7-point WHO ordinal scale means 5.8 vs. 5.3, p = 0.43) (Fig.1 D). Similarly, the blood tests and the viral loads were comparable in both groups. Study has permission from the ethic commission (AZ-249/20 S-EB). Results The study showed that cell specific cytokine expressions are distinct in survivors compared to non-survivors even at an early stage of the critical disease. Surviving Covid patients showed increased TFNá levels throughout all cell populations, which met significance in CD4+ T (Fig.2 A) Cells and CD135+ DC. (Fig. 4 C). IL-6 levels, however, were significantly lower in CD4+ T cells of survivors (Fig. 2 B). Similarly, proinflammatory, classical CD16+ monocytes of non-survivors exhibited an increase in IL-6 and IL-1â. Moreover, dendritic cells of non-survivors seemed to be exhausted revealing less TNFá and IL-6 and IL-1â (Fig 4) Conclusion: Taken together, a disability of monocyte activation and exhaustion of dendritic cell reaction was associated with a worsened outcome of severely ill Covid-19 patients [2,3]. On the contrary a sufficient TNFá response, especially of CD4 and dendritic cells might be required to overcome the infection. Therefore, our findings suggest that measuring cell specific levels of cytokines and cell population shifts might be of high clinical relevance to predict the outcome of the disease and offer new therapeutical options for these patients.

Burden of Covid.19 in Long.Term.Care Facilities: Preliminary Results of a Multicentre Cohort.Study from Eastern and Western Switzerland

Background: COVID-19 outbreaks with high mortality rates have been reported from long-term care facilities (LTCFs) worldwide despite infection control and prevention (ICP) measures. However, no systematic data exist on COVID-19 burden and its risk factors in Swiss-LTCFs. Aims: to assess (i) COVID-19 incidence and-related mortality for the year 2020 and their influencing factors, (ii) vaccination rates of residents and health care workers (HCW). Methods: LTCFs from cantons of St Gallen (SG) and Vaud (VD) (Eastern and Western Switzerland) were invited to participate in this cohort study. In May 2021, we collected COVID-19 cases and-related deaths 2020 and their potential risk factors at institutional level (e.g. size, number of single beds, staffing, ICP measures, aggregated resident characteristics) as well as vaccination rates of residents and HCW. Risk factor analysis and prospective surveillance of COVID-19 is ongoing. Results: We enrolled a total of 59 institutions (33 from SG, 26 from VD), with a median of 46 (IQR 33.69) occupied beds. In 2020, median COVID-19 incidence was 38.6 per 100 occupied beds, with higher rates in VD than in SG (48% vs. 29.4%, p = 0.028) (Fig. 1). Rates varied widely among LTCFs, with some institutions reporting no COVID-19 cases. On average (median), one-fifth (20%) of COVID-19 cases died and COVID-19 related deaths accounted for 21.6% of total deaths. Regarding ICP measures, 54/59 institutions (91.5%) recommended using gowns in contact with COVID-19 patients, whilst use of other PPE (i.e. FFP2 masks, glows and googles) was more heterogeneous. Only a few LTCFs reported having ever used regular testing of asymptomatic residents (6/59, 10.2%) or HCW (14/59, 23.7%) as a prevention strategy. Nearly half of them (27/59, 45.8%) never banned visits or only in outbreak situations. Of 2786 residents, a median of 72.2% per facility received ≥1 dose of COVID-19 vaccine. COVID-19 vaccine uptake among HCW was low (28.6%) (Fig. 1). Conclusion: COVID-19 burden was highly heterogeneous in Swiss LTCFs. Further analyses will reveal factors, which could potentially explain these differences. Of note, we found a relatively high COVID-19 vaccine uptake among care home residents, whilst vaccine coverage of HCW is low.

Evaluation of ward-level risk factors for nosocomial COVID-19 outbreaks: A matched case-control study

Introduction: The prevention of SARS-CoV-2 outbreaks in acute care hospitals is a major challenge. In the second wave of the pandemic, we observed several wards with outbreaks whereas others were spared. Objectives: We aimed to investigate risk factors for nosocomial COVID-19 outbreaks on a ward level. Methods: We conducted a matched case-control study in our tertiary care centre with over 700 beds by defining outbreak (≥ 2 nosocomial patients infected within a 14-day period) and control wards. Nosocomial infection was defined if a patient tested positive for COVID-19 on day 5 or later of hospitalisation. Matching was done 1:1 for approximate number of beds (± 10) and the time of the outbreak. The beginning of the outbreak was defined as the day of the first positively tested nosocomial COVID-19 case on the ward. Intensive care units and designated COVID- 19 wards were excluded. Presumed ward-, patient- and staff-specific variables were investigated. Paired Wilcoxon signed-rank test was used to compare variables between outbreak- and control wards. Results: From July to December 2020, we observed 9 outbreak wards (surgical and medical, range of beds 17 - 31, range nurses 19 - 41 per ward) with a total of 40 patients infected (range 2-7 per ward). The percentage of healthcare workers (HCW) tested positive within a period of 14 days prior until 2 days after the start of the outbreak was the only significant risk factor (9.7% vs 2.7%, p = 0.04). No difference in the percentage of infected HCW was observed in a time period further preceding the start of the outbreak (3 months to 2 weeks). Outbreak wards trended towards a higher number of beds per room (2.22 vs 1.97, p = 0.09) and a younger HCW age (33.3 vs 36.2 years, p = 0.17) compared to control wards. No association was found for factors reflecting work-load, patient turnover, or work experience of HCW (Table). Conclusion: Increased numbers of infected HCW shortly before the outbreak seem to be a risk factor for nosocomial SARS-CoV-2 outbreaks. This supports the notion that infected HCW are an important source of nosocomial COVID-19 and underscores the importance of adequate infection control- and prevention measures of HCW in- and outside the hospital. (Figure Presented).

What will infection prevention look like in 2030-results of the first round of a global crystal ball exercise

Introduction: Healthcare delivery is currently undergoing radical changes and so will the demands for effective Infection prevention in healthcare (IPC). Objectives: We initiated a global collaboration among IPC professionals to imagine the status of IPC in 2030 to inform the present. Methods: In JAN 2019, a purposive sample of 44 IPC professionals around the globe were invited to answer a 10-item online questionnaire, including 2 demographics, 4 housekeeping and 4 open-ended core questions: (Q1) “status of IPC in 2030”, (Q2) “position & people in charge of IPC”, (Q3) “necessary skills”, and (Q4) “open questions”. The latter were each submitted to inductive content analysis and displayed by semi-quantitative network mapping, the remainder reported descriptively. Results: Overall, 18 of 44 (41%) invited responded JAN-MAR 2019 (6 US, 2 CA, 2 CH, 1 FR, DE, MX, NL, SG, UK, each;15 with physician, 3 with nurse, and 1 with management background;all in senior positions). The main emerging themes for Q1 were “multidrug-resistant organisms”;“automatisation of data collection, processing & feedback” with the sub-themes 'robotics', 'monitoring', 'surveillance', 'short-circuit feedback';“system integration & broadening of IPC” with 'patient participation';“global perspective” with 'low/middle income country challenges', 'outpatient';“behaviour”;and “implementation” (Figure). The views were predominantly positively (66%) oriented. Q2 and Q3 yielded a broad range of professional profiles, ranging from data, behaviour, implementation, communication know-how and skills, positioning IPC highly in healthcare institutions and beyond. Similarly, Q4 covered a large area including medicine, life-science, data science, social science, organisational and political questions. Conclusion: The first round of the Future IPC project produced a mainly positive picture of ICP in 2030. The project will continue with further rounds of multi-method inquiry with evolving participation (including an assessment of changes attributable to insights gained during the SARS-CoV-2 pandemic) to serve as a roadmap for developing this critical field of medicine.

Longitudinal assessment of team safety culture and leadership regarding influenza and COVID-19 preventive measures: The hospital associated influenza prevention study (HAIP)N

Introduction: Prevention of hospital associated infections requires continuous monitoring and intervention. Team safety culture and leadership are key dimensions associated with infection prevention. Objectives: The aim of this study was to compare team safety culture and leadership in health care workers (HCW) regarding influenza and COVID-19 preventive measures before and during the COVID-19 pandemic. Methods: A longitudinal descriptive design was used to analyze data collected in a tertiary hospital in Switzerland across 2 years (2019/20 and 2020/21) reflecting the situation before and during COVID-19. Team safety culture was assessed for hand hygiene, mask wearing and vaccination (influenza/COVID-19 20/21) with adapted items of the safety attitude questionnaire (SAQ, Sexton et al., 2006) and adapted items of the Leadership Practices Inventory (LPI, Kouzes & Posner, 2003). Data were analyzed descriptively with frequencies and percentages, median and interquartile ranges. Results: In 2019/2020 49 HCW participated in the study and 59 in 2020/21. In both years, the majority were nurses, midwives and female (98%), about two thirds were below 40 years. Overall participants rated team safety culture as high for preventive measures with the exception of influenza vaccination coverage. For all three preventive measures there is an increase from 2019/20 to 2020/21 (table 1a). For 2020/21 only, results show that it is easier to address team safety culture issues regarding COVID-19 vaccination compared to influenza vaccination (figure 1 not attached). Perceived leadership for infection prevention by direct supervisor increased across all items during the COVID-19 pandemic (table2b). Conclusion: It will be important to maintain the increase in team safety culture and leadership in 2020/21. The differences in the ease to discuss either influenza or COVID-19 vaccination in respect to safety issues need to be addressed in by prevention initiatives. (Figure Presented).

Use of respirator vs. surgical masks in healthcare personnel and its impact on SARS-COV-2 acquisition-a prospective multicentre cohort study

Introduction: There is insufficient evidence regarding the role of respirators in the prevention of SARS-CoV-2 infection. Objectives: We analysed the impact of filtering facepiece class 2 (FFP2) vs. surgical masks on the risk of SARS-CoV-2 acquisition in Swiss healthcare workers (HCW). Methods: Our prospective multicentre cohort enrolled HCW from June to August 2020, who were asked about COVID-19 risk exposures/behaviours, including preferred mask type when caring for COVID-19 patients outside of aerosol-generating procedures (AGP). HCW performing AGP were also asked about universal FFP2 use (i.e. irrespective of patients' COVID-19 status). We assessed the impact of FFP2 on i) self-reported SARS-CoV- 2-positive nasopharyngeal PCR/rapid antigen tests (weekly surveys), and ii) SARS-CoV-2 seroconversion (baseline to January/February 2021). Results: We enrolled 3'259 participants from nine healthcare institutions, whereof 716 (22%) preferentially used FFP2 respirators. Among these, 81/716 (11%) reported a SARS-CoV-2-positive swab, compared to 352/2543 (14%) surgical mask users (median follow-up 242 days);seroconversion was documented in 85/656 (13%) FFP2 and 426/2255 (19%) surgical mask users. Adjusted for baseline characteristics, COVID-19 exposure, and risk behaviour, FFP2 use was marginally associated with a decreased risk for SARS-CoV-2-positive swab (aHR 0.8, p = 0.052) and seroconversion (aOR 0.7, p = 0.053);household exposure was the strongest risk factor (aHR for positive swab 10.1, p < 0.001;aOR for seroconversion 5.0, p < 0.001). In subgroup analysis, FFP2 use was clearly protective among HCW with frequent (> 20 patients) COVID-19 exposure (aHR 0.7, p < 0.001;aOR 0.6, p = 0.036). Universal FFP2 use during AGP showed no additional protective effect (aHR 1.1, p = 0.7;aOR 0.9, p = 0.53). Conclusion: FFP2 compared to surgical masks may convey additional protection from SARS-CoV-2 for HCW with frequent exposure to COVID-19 patients. (Figure Presented).

Does COVID-19 trigger changes in attitudes and behaviour of respiratory infection prevention measures? First results of health-care-associated influenza prevention project (HAIP)

Introduction: Results of the HaIP showed that during the last influenza seasons attitudes and adherence with infection preventive measures against the transmission of influenza remained stable. Objectives: To describe changes in attitudes and behaviour of health care worker (HCW) in infection prevention measures (wearing mask, hand hygiene, Influenza vaccination) during winter season before and after COVID-19. Methods: We collected data on 3 pilot wards during Influenzaseason 19/20 and 20/21 in the cantonal hospital of St.Gallen, a tertiary 700-bed hospital in eastern Switzerland. Adherence with hand hygiene was recorded by clean care monitor from Swissnoso according to the 5 moments (WHO). Data on Influenza and COVID- 19 vaccination rates were obtained by personal medical services. HCW's perceived importance of- and self-reported behaviour of influenza preventive measures were assessed with a questionnaire. In 20/21 the questions were adapted to cover for COVID-19. Results: Observed adherence with hand hygiene increased significantly from 68 to 78% (p < 0.001) as did self-reported adherence to wearing mask from 10 to 98% (p < 0.001). The other observed behaviours where not significant (table1a). Influenza vaccination rate reminded low over both seasons. Self-reported and observed Covid-19 vaccination rate was significantly higher than influenzavaccination rate (32% versus 17% and 27% versus 10%). The perceived importance of hand hygiene remained high, the attitudes toward own influenza vaccination did not change over the seasons(Table1b). A relevant change can be observed in mask wearing which was perceived as with low importance(2 out of 10) before the SARS-CoV2 pandemic and most important(10out of10) thereafter. Conclusion: The emergence of the COVID-19 pandemic had an important impact on attitudes and behaviour of infectious disease prevention measures. As expected the change could be perceived in attitude and the behaviour toward wearing a mask but also increased the adherence with hand hygiene. Vaccination coverage has been and remains low for both COVID-19 and Influenza but the significantly lower readiness for influenza underscores the specific vaccination scepticism about influenza.