Seroprevalence of Novel Coronavirus SARS-CoV-2 at a Community Hospital Emergency Department and Outpatient Laboratory in Northern Orange County, California

Abstract

Introduction The severe acute respiratory syndrome related coronavirus 2 (SARS-CoV-2) has infected more than 20 million people worldwide, and the spread is most prevalent in the USA, where California had accounted over 240,000 cases in the initial 5 months of the pandemic. To estimate the number of infected persons in our community, we conducted a cross-sectional study to estimate seroprevalence of SARS-CoV-2 infection. Methods This cross-sectional study evaluated the presence of immunoglobulin G, antibody for SARS-CoV-2 during the time period of July 15, 2020, to July 27, 2020. Testing was done on serum samples from patients who had visited affiliated outpatient clinics or our emergency department. Additionally, we collected age, gender, ethnicity, race, and location of testing. Results Eight hundred sixty-five tests were included in the study. The outpatient clinics cohort accounted for 56% of results and emergency department (ED) contributed 44%. The positive percentage of SARS-CoV-2 test was 9.4% (95% CI: 0.08-0.12). The positivity rates of the outpatient (5.6%) and ED (14.2%) setting differed. The prevalence of SARS-CoV-2 IgG was greatest in those that identified as Hispanic/Latino, 18.1% versus 13.4% in other groups. Specifically compared to the non-Hispanic/Latino population, the prevalence was significantly higher, with a relative risk of 2.73 (95% CI: 1.8-4.1), p < 0.0001. Conclusion The low antibody positivity rate in the community indicates the need for a vaccine. The Hispanic/Latino patient population should be considered for increased education on preventing transmission and acquisition of COVID-19 as well as being considered as a priority for vaccination once a vaccine is available.

SARS-CoV-2 Cumulative Incidence and Period Seroprevalence: Results From a Statewide Population-Based Serosurvey in California

“…Results from this study indicated large disparities in burden of infection among Californians, particularly among Hispanic/Latinx persons compared with non-Hispanic/Latinx White persons. These data support other findings in California, which have documented seroprevalence up to 3 times as high among Hispanic/Latinx persons compared with non-Hispanic/Latinx White persons [ 6 , 22 , 23 ]. We also reported differences in seroprevalence by insurance status and workplace.…”

“…The estimated IFR was 0.8% for adults, and we found that only 1 in 3 SARS-CoV-2 infections in adults was reported to the CDPH through early November 2020. Disparities documented in our study by ethnicity and insurance status may be larger than previously suggested by local seroprevalence studies [ 6 , 23 ] and surveillance data [ 28 ]. Taken together, these data underscore the continued need to focus public health interventions, including access to testing and vaccination in socioeconomically vulnerable communities, which are the most heavily impacted.…”

A Prospective Study of Key Correlates for Household Transmission of Severe Acute Respiratory Syndrome Coronavirus 2

“…We also found that Hispanic or Latino ethnicity was a correlate of decreased viral load. One possibility for this finding is this population was enrolled slightly later in the course of infection, consistent with the higher seropositivity reported in this population [ 25 , 26 ] and the decreased risk of acquisition identified in the Hispanic/Latino population in this report.…”

Orange County, California COVID-19 Vaccine Equity Best Practices Checklist: A Community-Centered Call to Action for Equitable Vaccination Practices

“…During the COVID-19 pandemic, low-income communities and communities of color within OC have experienced higher rates of SARS-CoV-2 infection and COVID-19 morbidity and mortality, similar to patterns observed nationwide. 24–26 Within California, a major factor in this higher rate of infection rests in the over-representation of low-income communities and communities of color in front-line public-facing low-wage essential jobs such as farm work, cleaning and janitorial, and food industries. 27 This has left 5.7 million of these workers at heightened risk of COVID-19.…”