ABSTRACT
Background. Environmental surveillance of SARS-CoV-2 via wastewater has become an invaluable tool for population-level surveillance of COVID-19. More highly resolved environmental sampling approaches may also be useful for surveillance. Built environment sampling may provide a spatially refined approach for surveillance of COVID-19 in congregate living settings. Methods. We conducted a prospective study of 10 long-term care homes (LTCHs) in both urban and rural settings in Ontario Canada between September 2021 and April 2022. Floor surfaces were sampled weekly at multiple locations within each building and were analyzed for the presence of SARS-CoV-2 using qPCR. The exposure variable was detection of SARS-CoV-2 on floors. The primary outcome was the presence of a COVID-19 outbreak. We calculated the test characteristics of the presence of SARS-CoV-2 on floors for detection of COVID-19 outbreaks. Results. We followed 10 LTCHs for 214 cumulative weeks, and collected 3,219 swabs from 183 unique locations. Overall, 15 COVID-19 outbreaks occurred with 74.9 cumulative weeks of outbreaks. During time periods when there were outbreaks of COVID-19 the proportion of floor swabs positive for SaRS-CoV-2 was 50.8% (95% CI: 47.7-53.9). During time periods where there were no outbreaks of COVID-19 the proportion of floor swabs positive was 15.8% (95% CI:14.3-17.3). Using the proportion of positive floor swabs for SARS-CoV-2 to predict COVID-19 outbreak status for a given week, the area under the receiver operating curve was 0.84 (95% CI: 0.76-0.92). Using thresholds of >=10%, >=30%, and >=50%, the prevalence of floor swabs positive for SARS-CoV-2 yielded positive predictive values for outbreak of 0.52 (0.43-0.61), 0.65 (0.53-0.75), and 0.72 (0.58-0.83) respectively, and negative predictive values of 0.93 (0.86-0.97), 0.85 (0.78-0.91), and 0.80 (0.73-0.86) respectively (Figure 1). 13 outbreaks had floor sampling performed in the week prior to them being identified, and of these 7 (54%) had positive swab proportions exceeding 30% in the week prior to the outbreak. Figure 1. Test characteristics of built environment floor swabs for predicting COVID-19 outbreaks in LTCH. Figure 1. Test characteristics of different thresholds for percentage of floor swabs positive for SARS-CoV-2 at a given LTCH for predicting active COVID-19 outbreak in the same building in the same week. NPV = negative predictive value, PPV = positive predictive value, Sens = sensitivity, Spec = specificity. Conclusion. Detection of SARS-CoV-2 on floors is strongly associated with COVID-19 outbreaks in LTCHs. These data suggest a potential role for floor sampling in improving early outbreak detection and management.
ABSTRACT
Introduction: Severe COVID-19 patients present with a hypercoagulable state, complement activation and endothelial perturbation, which result from an excessive inflammatory response. Thromboinflammation is one important mechanism underlying the COVID-19-associated coagulopathy and the increased risk of thrombosis. Bergamo city is one of the first and most affected area by SARS-CoV-2 infection in the world. For this reason, since the beginning we were actively involved in recruiting convalescent COVID-19 patients, in a program of selection of candidates for convalescent plasma donation. In a large cohort of convalescent COVID-19 patients, we aimed to characterize markers of coagulation activation and endothelial perturbation, in order to explore whether the COVID-19-related hemostasis activation might persist afterwards and evaluate its possible association with the degree of severity of the previous infection, and/or with demographic characteristics, or anti-SARS-CoV-2 antibody levels. Methods: In 392 convalescent COVID-19 patients (216M/176F, median age: 46 years) plasma levels of fibrinogen, protein C, protein S, factor V, factor VIII, factor XIII, D-dimer, von Willebrand factor (vWF), prothrombin fragment F1+2 were measured at the recruitment, i.e. 1-5 months from recovery. Samples were tested for the anti-SARS-CoV-2 antibodies, including anti-S IgG (Anti-S Ab) and anti-N IgG (Anti-N Ab) antibodies at enrollment and at each scheduled subsequent visits. Results: Levels of fibrinogen, D-dimer, von Willebrand factor, protein S and protein C were significantly higher (p<0.05) in patients who were hospitalized for severe COVID-19 as compared to patients who were treated at home. There was no correlation between levels of coagulation biomarkers and days from end of symptoms. Male gender, age > 40 years, and severe form of COVID-19 were identified as independent predictors of high levels of both anti-S and anti-N Ab (p<0.001). Among hemostatic biomarkers, fibrinogen (p<0.01) and vWF (p<0.05) independently predict high levels of anti-S Ab. In particular, vWF levels positively correlated with anti-S Ab levels (vWFantigen r=0.188;vWF-activity r=0.241 and vWF-RiC of r=0.223, p<0.01). Evaluation of anti-SARS-CoV2 antibody levels at different time points during follow up revealed that 30% of patients displayed high levels of anti-S Ab until more than 8 months from the end of symptoms. Conclusions: Convalescent patients, with a history of severe COVID-19 had a persistent endothelium activation, despite of disease clinical remission even after 9 months from end of symptoms. Furthermore, fibrinogen and vWF levels predicted high levels of Anti-S Ab. Among demographic characteristics, gender, age and severe disease can be predictors of increased antibody response. These findings suggest that inflammation, coagulation and endothelial dysfunction may persist after recovery and may explain the findings of persistent clinical symptoms reported in these patients after healing from COVID-19.
ABSTRACT
Background. Hand hygiene (HH) is a standard infection prevention and control precaution to be applied in healthcare settings to prevent transmission of COVID-19. Many healthcare institutions observed significant improvements in HH performance during wave one of the COVID-19 pandemic but the sustainability of this change is unknown. Our aim was to evaluate long-term HH performance throughout subsequent waves of the pandemic across acute care hospitals in Ontario, Canada. Methods. HH adherence was measured using a previously validated group electronic monitoring system which was installed on all alcohol handrub and sink soap dispensers inside and outside each patient room across 56 inpatient units (35 wards and 21 critical care units) spanning 13 acute care hospitals (6 university and 7 community teaching hospitals) from 1 November 2019 to 31 May 2021. Daily HH adherence was compared with daily COVID-19 case count across Ontario. During this period, weekly performance continued to be reported to units but unit-based quality improvement discussions were inconsistent due to the COVID-19 response. Results. Figure 1 depicts daily aggregate HH adherence plotted against the new daily COVID-19 case count across Ontario. An elevation in HH adherence was seen prior to the start of the first wave, rising almost to 80% and then remained above 70% for the peak of wave one. During waves two and three, peak COVID-19 case counts were associated with a maximum HH adherence of 51%, only marginally above the pre-pandemic baseline. After the end of wave one (from 1 July 2020 to 31 May 2021) the median HH performance was only 49% (interquartile range 47%-50%). Conclusion. Initial improvements in HH adherence preceding the start of the COVID-19 pandemic were not sustained, possibly due to increasing comfort and reduced anxiety associated with providing care to COVID-19 patients leading to a perception of reduced COVID-19 transmission risk. These findings highlight the need for HH monitoring to be tied to longitudinal unit-led quality improvement in order to achieve durable changes in practice.
ABSTRACT
Background: Hypercoagulability, complement activation and endothelial perturbation characterize sever COVID-19. After disease remission, a proportion of convalescent subjects still experience post-COVID-19 symptoms. No information is available on persistence of hemostatic alterations in this setting. Bergamo city, represents one of the first and most affected area by SARS-CoV-2 infection in the world. For this reason, since the beginning we were actively involved in recruiting CCP donors. Aims: In a large cohort of CCP donors, we aimed to characterize biomarkers of hypercoagulability and of endothelial perturbation in order to find associations with disease severity, demographic characteristics, and anti-SARS-CoV-2 antibody levels. Methods : Candidate CCP donors were tested for the anti-SARSCoV-2 antibodies, including anti-S IgG antibodies (Anti-S Ab) and anti-N IgG antibodies (Anti-N Ab). In addition, the following plasma biomarkers were assessed: fibrinogen, protein C, protein S, factor V, factor VIII, factor XIII, D-dimer, and von Willebrand factor (vWF). Results: 425 CCP candidates (275M/150F, age range 19-67 years) were admitted to donation. Male gender, age > 40 years, and severe form of COVID-19 were identified as independent predictors of high levels of both anti-S and anti-N Ab ( p <0.001). Among hemostatic parameters, levels of vWF antigen, vWF activity and protein C were significantly higher in CCP donors who had severe COVID-19 compared to donors who had non-severe COVID-19 ( p <0.001). Furthermore, vWF levels positively correlated with anti-S Ab levels (vWF-antigen r=0.216 vWF-activity r=0.257 and vWFRiCof r=0.226, p <0.01). Conclusions: Our data show that gender, age and severe disease can be predictors of an increased immunological response. Furthermore, convalescent subjects show a persistently high vWF levels, suggesting a persistence of the endothelial activation, despite of clinical disease remission.
ABSTRACT
Background: Severe COVID-19 is associated with a profound derangement of the hemostatic system characterized by hypercoagulability, complement activation and endothelial cell perturbation. After disease resolution, some convalescent subjects still experience post-COVID-19 symptoms. No information is available on persistence of hemostatic alterations in this setting. Bergamo city, represents one of the first and most affected area by SARS-CoV-2 infection in the world. For this reason, since the beginning we were actively involved in hyperimmune plasma collection from COVID-19 convalescent subjects. Aims: In this study, in a large cohort of convalescent donors of hyperimmune plasma, we aimed to characterize select hemostatic parameters of hypercoagulability and endothelial cell perturbation and their association with disease severity, demographic characteristics, and antibody levels. Methods: Recovered COVID-19 patients eligible to plasma donation were tested for the SARS-CoV-2 antibodies by the anti-N IgG SARSCoV- 2 antibodies (Abbott Laboratories, IL, USA, Anti-N Abs), and/or the anti-S IgG SARS-CoV-2 antibodies (Liaison-Diasorin, Sallugia-VC, Italy, Anti-S Abs), according to the manufacturer's instructions. Fibrinogen, protein C, protein S, factor V, factor VIII, factor XIII, D-dimer, and von Willebrand factor (vWF) were assessed. Results: 425 subjects have been included (275M/150F) with a median age of 48 years (range: 19-67 years). Among convalescent subjects admitted to the donation, male gender, age > 40 years, and previous hospitalization for COVID-19, were identified as independent predictive factors for significantly (p<0.001) higher levels of SARS-CoV-2 IgG (both anti-S and anti-N). Hemostatic parameters including fibrinogen, protein S, factor V, factor VIII, factor XIII, and D-dimer were not different between severe and non-severe COVID-19. Differently, convalescent subjects with previous severe COVID-19 showed significantly higher levels of vWF (124±40 vs 121±41 %, p<0.001) and PC (119±19 vs 109±19 %, p<0.001) compared with non-severe COVID-19 subjects. In addition, significant positive correlations were found between vWF levels and anti-S Abs (vWF antigen r=0.216;vWF activity r=0.257 and vWF RiCof r=0.226, p<0.01). Summary/Conclusion: Our data show that gender, age and severe disease can be potential predictors of an increased immunological response. Furthermore, convalescent subjects show a persistently high vWF levels, suggesting a persistence of the endothelial activation, despite of clinical disease remission.