ABSTRACT
Background: People with cystic fibrosis (PwCF) have chronic, pronounced respiratory damage and have been considered among those at highest risk for serious harm from SARS-CoV-2. Numerous clinical studies have reported that individuals with CF in North America and Europe, although highly susceptible to COVID-19, do not have mortality levels that exceed those of the general population. Method(s): To understand features that might influence lethality of COVID- 19 in PwCF, we tested potential relationships between CFTR and viral pathogenesis. As one approach to evaluate impact of CF transmembrane conductance regulator (CFTR) on COVID-19 severity, independent sets of blood samples fromvirally infected individualswere genotyped. Bloodwas obtained from 424 U.S. patients hospitalized with severe COVID-19 and a much larger European cohort of 7147 healthy individuals and 2587 individuals with severe COVID-19. Deoxyribonucleic acid in both studies was probed for the F508del variant. In other experiments, we investigated the possibility that lack of CFTR might alter viral binding and propagation. We used human bronchial epithelial cell (HBEC) monolayers from individuals without functional CFTR for this purpose. Finally, we examined effects of CF airway secretions and features such as viscosity, pH, and protease/anti-protease imbalance during SARS-CoV-2 infection. Result(s): We found no evidence of a relationship between deficient CFTR function (based on carrier status for the severe F508del defect) and clinical outcomes from COVID-19. In addition, viral propagation studies using airway epithelial monolayers (a model that reproduces many aspects of in vivo tissue biology) were not influenced by homozygous absence of CFTR. We show that levels of angiotensin converting enzyme-2 receptor messenger ribonucleic acid (mRNA) appear normal in CF primary epithelium, whereas transmembrane serine protease 2 mRNA is variable but lower ( p < 0.001) in a manner that correlates with viral infectivity (R2 = 0.76). Dependence of viral proliferation on features of CF mucosal fluid-including pH (viral replication optimum at pH 7-7.5), viscosity (diminished propagation in highly viscous apical media), and protease/ anti-protease imbalancewere identified as likely contributors to efficiency of SARS-CoV-2 replication and pathogenesis. Conclusion(s): These findings using patient data, CF and non-CF primary airway epithelia, and CF airway secretions fail to demonstrate a causal relationship between loss of CFTR and susceptibility to severe COVID-19. Notwithstanding the caveat that addition of virus in small buffer volumes disrupts airway surface liquid depth and composition, our findings also argue against a role for CFTR during acute infection of airway cells in vitro. On the other hand, chronic disruption of periciliary liquid, diminished pH, altered protease/anti-protease homeostasis, and increased fluid viscosity (sequelae that occur in CF lungs) were implicated as contributors to impaired SARS-CoV-2 propagation. Such studies provide a basis for future work to test relationships between CFTR and severity of COVID-19. Copyright © 2022, European Cystic Fibrosis Society. All rights reserved
ABSTRACT
Background. Measuring SARS-CoV-2 antibody prevalence in spent samples at serial time points can determine seropositivity in a diverse pool of individuals to inform understanding of trends as vaccinations are implemented. Methods. Blood samples collected for clinical testing and then discarded ("spent samples") were obtained from the clinical laboratory of a medical center in Atlanta. A convenience sample of spent samples from both inpatients (medical/surgical floors, intensive care, obstetrics) and outpatients (clinics and ambulatory surgery) were collected one day per week from January-March 2021. Samples were matched to clinical data from the electronic medical record. In-house single dilution serological assays for SARSCoV-2 receptor binding domain (RBD) and nucleocapsid (N) antibodies were developed and validated using pre-pandemic and PCR-confirmed COVID-19 patient serum and plasma samples (Figure 1). ELISA optical density (OD) cutoffs for seroconversion were chosen using receiver operating characteristic analysis with areas under the curve for all four assays greater than 0.95 after 14 days post symptom onset. IgG profiles were defined as natural infection (RBD and N positive) or vaccinated (RBD positive, N negative). Single dilution serological assays for SARS-CoV-2 nucleocapsid antibodies were validated using pre-pandemic and PCR-confirmed COVID-19 patient serum and plasma samples. ELISA optical density (OD) cutoffs for seroconversion were chosen using receiver operating characteristic (ROC) analysis with areas under the curve (AUC) for all four assays greater than 0.95 after 14 days post symptom onset. Results. A total of 2406 samples were collected from 2132 unique patients. Median age was 58 years (IQR 40-70), with 766 (36%) ≥ 65 years. The majority were female (1173, 55%), and 1341 (63%) were Black. Median Elixhauser comorbidity index was 5 (IQR 2-9). 210 (9.9%) patients ever had SARS-CoV-2 detected by PCR, and 191 (9.0%) received a COVID-19 vaccine within the health system. Nearly half (1186/2406, 49.3%) of samples were collected from inpatient units, 586 (24.4%) from outpatient labs, 403 (16.8%) from the emergency department, and 231 (9.6%) from infusion centers. Overall, 17.0% had the IgG natural infection profile, while 16.2% had a vaccination profile. Prevalence estimates for IgG due to natural infection ranged from 24.0% in week 2 to 9.7% in week 5, and for IgG due to vaccine from 4.4% in week 2 to 32.0% in week 6 (Table, Figure 2). Conclusion. Estimated SARS-CoV-2 IgG seroprevalence among patients at a medical center from January-March 2021 was 17% by natural infection, and 16% by vaccination. Weekly trends likely reflect community spread and vaccine uptake.
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Purpose of Study Healthcare-associated transmission of SARSCoV- 2 is relatively rare and may be difficult to quantify. We performed an epidemiological investigation and SARSCoV- 2 genome sequencing to define the source and scope of a SARS-CoV-2 outbreak in a cluster of hospitalized patients. Methods Used We conducted an outbreak investigation after identifying hospital-onset COVID-19 in patients receiving hemodialysis in January 2021. Electronic medical record review, staff interviews, review of employee schedule logs, and contact tracing were used to determine the outbreak timeline and identify potentially exposed healthcare workers (HCW). SARS-CoV-2 genomes were sequenced from residual nasopharyngeal swab samples from 6 individuals in the outbreak investigation and compared to sequences from 14 patients in the same facility, 54 patients in nearby facilities, and 375 publicly available sequences from individuals in the state of Georgia. Summary of Results Eight patients with hospital-onset COVID- 19 were identified (Cases 1-8);all were receiving hemodialysis and 5 were bedded in a single inpatient nursing unit. Among 53 potentially exposed HCW, 29 underwent testing and 5 were positive (Cases 9-13). The suspected index patient (Case 1) was found to have been coughing and inconsistently wearing a mask during a hemodialysis session on the same day that 5 of the 7 other patients and one HCW (Case 10) were in close proximity in the hemodialysis unit (figure 1A). Further investigation revealed lack of use of curtain barriers in the hemodialysis bays, inconsistent use of personal protective equipment by HCW, and overcrowding of staff breakrooms. Among the only 6 samples available for phylogenetic analysis, SARS-CoV-2 sequences from 5 (4 patients and 1 HCW, Case 9) were identical and at least 4 SNPs removed from the next closest sequence in this study, supporting a transmission cluster (figure 1B ). The sequence from the sixth sample (HCW Case 10 ) was phylogenetically distinct, indicating an independent source of infection. Conclusions Lack of appropriate respiratory hygiene led to SARS-CoV-2 transmission during a single hemodialysis session, based on clinical and molecular epidemiology. Use of appropriate PPE for both patients and HCW and other infection prevention measures are critical to prevent SARS-CoV-2 transmission.
ABSTRACT
Introduction: COVID-19 has been associated with venous and arterial thrombotic complications. The objective of our study was to determine whether markers of coagulation and hemostatic activation (MOCHA) on admission could identify COVID-19 patients at risk for thrombotic events. Methods: COVID-19 patients admitted to a tertiary academic healthcare system from April 3, 2020 to July 31, 2020 underwent admission testing of MOCHA profile parameters (plasma d-dimer, prothrombin fragment 1.2, thrombin-antithrombin complex, and fibrin monomer). For this analysis we excluded patients on outpatient anticoagulation therapy preceding admission. Prespecified endpoints monitored during hospitalization included deep vein thrombosis, pulmonary embolism, myocardial infarction, ischemic stroke and access line thrombosis. Results: During the study period, 276 patients were included in the analysis cohort (mean age 59 ± 6.3 years, 47% female, 83% non-white race). Arterial and venous thrombotic events occurred in 43 (16%) patients (see Table). Each coagulation marker was independently associated with the composite endpoint (p<0.05). Admission MOCHA with ≥ 2 abnormalities was associated with the composite endpoint (OR 3.1, 95% CI 1.2-8.3), ICU admission (OR 3.2, 95% CI 1.8-5.5) and intubation (OR 2.8, 95% CI 1.5-5.5). Admission MOCHA with < 2 abnormalities (26% of the cohort) had sensitivity of 88% and a negative predictive value of 93% for an in-hospital endpoint. Conclusion: Admission MOCHA with ≥ 2 abnormalities identified COVID-19 patients at risk for a thrombotic event, ICU admission and intubation while < 2 abnormalities identified a subgroup of patients who were at low risk for thrombotic events. Our results suggest that an admission MOCHA profile can be useful to risk stratify COVID-19 patients. Further studies are needed to determine whether an admission MOCHA profile can guide anticoagulation therapy and improve overall clinical outcomes.(Figure Presented).