The emergence, surge and subsequent wave of the SARS-CoV-2 pandemic in New York metropolitan area: The view from a major region-wide urgent care provider

Abstract

Background: Describing SARS-CoV-2 testing and positivity trends among urgent care users is crucial for understanding the trajectory of the pandemic.

Objective: To describe demographic and clinical characteristics, positivity rates, and repeat testing patterns among patients tested for SARS-CoV-2 at CityMD, an urgent care provider in the New York City metropolitan area.

Design: Retrospective study of all persons testing for SARS-CoV-2 between March 1, 2020 and January 8, 2021 at 115 CityMD locations in the New York metropolitan area.

Patients: Individuals receiving a SARS-CoV-2 diagnostic or serologic test.

Measurements: Test and individual level SARS-CoV-2 positivity by PCR, rapid antigen, or serologic tests.

Results: During the study period, 3.4 million COVID tests were performed on 1.8 million individuals. In New York City, CityMD diagnosed 268,298 individuals, including 17% of all reported cases. Testing levels were higher among 20-29 year olds, non-Hispanic Whites, and females compared with other groups. About 24.8% (n=464,902) were repeat testers. Test positivity was higher in non-Hispanic Black (6.4%), Hispanic (8.0%), and Native American (8.0%) patients compared to non-Hispanic White (5.4%) patients. Overall seropositivity was estimated to be 21.7% (95% Confidence Interval [CI]: 21.6-21.8) and was highest among 10-14 year olds (27.3%). Seropositivity was also high among non-Hispanic Black (24.5%) and Hispanic (30.6%) testers, and residents of the Bronx (31.3%) and Queens (30.5%). Using PCR as the gold standard, SARS-CoV-2 rapid tests had a false positive rate of 5.4% (95%CI 5.3-5.5).

Conclusion: Urgent care centers can provide broad access to critical evaluation, diagnostic testing and treatment of a substantial number of ambulatory patients during pandemics, especially in population-dense, urban epicenters.

Figure 1:. COVID molecular and rapid antigen testing trends at CityMD in the New York metropolitan area.

A seven-day rolling average of tests is plotted to smooth temporal trends. PCR tests are denoted in turquoise and rapid antigen tests are in red. Panels A and B show daily tests performed and number of tests that were positive. Panel C shows the proportion of individuals who received their first positive test by PCR and antigen tests over time (individual-level daily positivity rate). Rapid antigen testing was only offered starting October. Note that initial positivity rates were high because tests were in short supply and testing criteria were stringent. PCR: Polymerase chain reaction.

Figure 2:. Main events potentially impacting the COVID-19 trends in NYC

Top panel shows PCR percent positivity for PCR tests done at CityMD (light blue) and in NYC (dark blue). The three periods of initial wave, low activity and second wave are shaded in red, blue, and yellow respectively. Bottom panel shows PCR (light blue) and rapid antigen tests (dark blue) positivity rates for CityMD testers focusing on the second wave of the pandemic in NYC. Raw data was used to calculate positivity rates in both plots to be able to visualize the spikes in cases occurring after events that might have facilitated increased in-person contacts. PCR: Polymerase chain reaction. POC: Point-of-care rapid antigen tests.

Figure 3:. Differences in COVID-19 PCR/rapid antigen test positivity and seropositivity by race/ethnicity

The top panel shows combined PCR and rapid antigen test positivity by race/ethnicity for individuals tested between March 2020 and January 2021. The bottom panel shows antibody positivity by race/ethnicity. Test positivity rates were higher among Native American, Hispanic, and NH Black testers, compared to NH White and Asian testers. NH: Non-Hispanic; Native Am./ Pacific Is./Alaskan Nat.: Native American/ Pacific Islander/Alaskan Native; PCR: Polymerase chain reaction

Figure 4:. SARS-CoV-2 seropositivity by age and gender between March 2020 and January 2021

Seropositivity for each age group is measured as a proportion of serologic testers who had their first positive serologic test between March 2020 and January 2021. For repeat serologic testers, subsequent positive tests were removed. Red curve is for females and the blue curve is for males. Testers with unknown gender are removed from this plot. F: Female; M: Male.