Concordance of SARS-CoV-2 Antibody Results during a Period of Low Prevalence.

Accurate, highly specific immunoassays for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are needed to evaluate seroprevalence. This study investigated the concordance of results across four immunoassays targeting different antigens for sera collected at the beginning of the SARS-CoV-2 pandemic in the United States. Specimens from All of Us participants contributed between January and March 2020 were tested using the Abbott Architect SARS-CoV-2 IgG (immunoglobulin G) assay (Abbott) and the EuroImmun SARS-CoV-2 enzyme-linked immunosorbent assay (ELISA) (EI). Participants with discordant results, participants with concordant positive results, and a subset of concordant negative results by Abbott and EI were also tested using the Roche Elecsys anti-SARS-CoV-2 (IgG) test (Roche) and the Ortho-Clinical Diagnostics Vitros anti-SARS-CoV-2 IgG test (Ortho). The agreement and 95% confidence intervals were estimated for paired assay combinations. SARS-CoV-2 antibody concentrations were quantified for specimens with at least two positive results across four immunoassays. Among the 24,079 participants, the percent agreement for the Abbott and EI assays was 98.8% (95% confidence interval, 98.7%, 99%). Of the 490 participants who were also tested by Ortho and Roche, the probability-weighted percentage of agreement (95% confidence interval) between Ortho and Roche was 98.4% (97.9%, 98.9%), that between EI and Ortho was 98.5% (92.9%, 99.9%), that between Abbott and Roche was 98.9% (90.3%, 100.0%), that between EI and Roche was 98.9% (98.6%, 100.0%), and that between Abbott and Ortho was 98.4% (91.2%, 100.0%). Among the 32 participants who were positive by at least 2 immunoassays, 21 had quantifiable anti-SARS-CoV-2 antibody concentrations by research assays. The results across immunoassays revealed concordance during a period of low prevalence. However, the frequency of false positivity during a period of low prevalence supports the use of two sequentially performed tests for unvaccinated individuals who are seropositive by the first test. IMPORTANCE What is the agreement of commercial SARS-CoV-2 immunoglobulin G (IgG) assays during a time of low coronavirus disease 2019 (COVID-19) prevalence and no vaccine availability? Serological tests produced concordant results in a time of low SARS-CoV-2 prevalence and no vaccine availability, driven largely by the proportion of samples that were negative by two immunoassays. The CDC recommends two sequential tests for positivity for future pandemic preparedness. In a subset analysis, quantified antinucleocapsid and antispike SARS-CoV-2 IgG antibodies do not suggest the need to specify the antigen targets of the sequential assays in the CDC's recommendation because false positivity varied as much between assays targeting the same antigen as it did between assays targeting different antigens.

COVID-19 Vaccination Gap in Admitted Trauma Patients: A Critical Opportunity.

BACKGROUND: Coronavirus disease 2019 (COVID-19) vaccination is the core strategy for pandemic management. We hypothesized that a vaccination gap might exist between emergency department (ED) patients admitted for trauma and other ED patients. STUDY DESIGN: This was an observational quality improvement study using electronic health record data at an academic level-1 trauma center. Participants were all patients presenting to the adult ED with a Tennessee home address between January 1 and June 1, 2021. We measured the proportional difference in vaccination between admitted trauma patients and other ED patients over time (by week) and association via Spearman's rank correlation coefficient. Binary logistic regression facilitated covariate analysis to account for age, sex, race, home county, and ethnicity without and then with interaction between trauma admission and time. Geographic visual analysis compared county-level vaccination rates with odds of trauma admission by home county using a bivariate chloropleth map. RESULTS: The proportional difference in vaccination between trauma-admitted and other ED patients increased over time (Spearman's = 0.699). Adjusting for age, sex, race, home county, and ethnicity, there was a statistically significant vaccination difference between trauma-admitted and other ED patients (odds ratio = 0.53, 95% CI 0.43-0.65, p < 0.0001). Geographic analysis revealed increased trauma admission odds and lower vaccination rates in surrounding counties compared with Davidson County. CONCLUSIONS: We observed a widening COVID-19 vaccination gap between trauma-admitted and other ED patients. Vaccine outreach during trauma admission may provide a valuable point of contact for unvaccinated patients.

Potential impact of oral flora dispersal on patients wearing face masks when undergoing ophthalmologic procedures.

OBJECTIVE: The purpose of this study is to investigate the amount of oral flora dispersion towards the ocular surface in relation to various face mask scenarios. METHODS AND ANALYSIS: Thirty participants were recruited for this prospective cross-sectional study. Each participant was seated and instructed to hold a blood agar plate perpendicular to the bridge of their nose and facing downward. Participants then partook in three unique face mask scenarios: no face mask, surgical face mask and surgical face mask with tape securing the superior edge. During each scenario, participants were instructed to forcefully exhale for 5 s three times. The primary outcome measure was the number of colony-forming units (CFUs) grown on each face mask scenario-specific plate. RESULTS: Thirty participants were recruited for the study, and a total of 90 chocolate agar plates were successfully incubated. The proportion of detecting any CFU was 6.67% (95% CI: 0.818% to 22.1%) for no mask scenario, 0% (95% CI: 0% to 11.6%) for mask scenario and 3.33% (95% CI: 0.0844% to 17.2%) for mask-taped scenario. The mean differences in proportion of detecting any CFU were 3.33% (95% CI: 0% to 10%, p=0.309) for no mask versus mask taped, 3.35% (95% CI: 0% to 10%, p=0.307) for mask taped versus mask and 6.68% (95% CI: 0% to 16.7%, p=0.142) for no mask versus mask. CONCLUSION: This study showed no difference in bacterial dispersion towards the ocular surface when comparing no face mask, a surgical face mask without tape or a surgical face mask with tape.