key: cord-266808-wyuodzyt
authors: Nagler, Arielle R; Goldberg, Eric R; Aguero-Rosenfeld, Maria E; Cangiarella, Joan; Kalkut, Gary; Monahan, Carolyn Rooke; Cerfolio, Robert J
title: Early Results from SARS-CoV-2 PCR testing of Healthcare Workers at an Academic Medical Center in New York City
date: 2020-06-28
journal: Clin Infect Dis
DOI: 10.1093/cid/ciaa867
sha: 
doc_id: 266808
cord_uid: wyuodzyt

COVID-19 RT-PCR employee-testing was implemented across NYU Langone. Over eight-weeks, 14,764 employees were tested: 33% of symptomatic employees, 8% of asymptomatic employees reporting COVID-19 exposure, 3% of employees returning to work were positive. Positivity rates declined over time possibly reflecting the importance of community transmission and efficacy of PPE.

A c c e p t e d M a n u s c r i p t

A novel coronavirus, SARS-CoV-2, was identified in late 2019 in Wuhan, China, and rapidly became a pandemic. New York quickly became the American epicenter. [1] HCW are at the frontline in the fight against COVID-19 and are at increased risk for infection. In an early review of 139 hospitalized COVID-19 patients in China, 41% had nosocomial COVID-19. [2] As a group at high-risk for exposure, widespread testing for HCW has been proposed in the literature. [3] Although specifically designed for symptomatic testing, RT-PCR can be used to detect COVID-19 infection in both symptomatic and asymptomatic individuals. Identifying both asymptomatic and symptomatic HCW can promote a safe environment within the healthcare system as asymptomatic carriers can transmit COVID-19. [4, 5] NYULH is an academic medical center encompassing four hospital campuses in Manhattan, Brooklyn, and Long Island and over 250 ambulatory sites, with approximately 43,000 employees. At the center of the hardest hit region in the United States, from March 14 to May 18, 5,767 COVID-19 patients were admitted to NYULH. Herein we describe the widespread employee COVID-19 testing program that was initiated at NYULH to promote a safe and informed environment for employees and patients.

On March 25, 2020, NYULH began a dedicated, on-demand COVID diagnostic program for employees. Over the following eight weeks three groups were tested: 1) symptomatic staff with fever or respiratory illness; 2) asymptomatic employees with self-reported exposure to COVID-19 which included any degree or duration of contact with an individual who had a documented COVID-19 infection in the work place or in the community; and 3) all employees who were returning to work in services that had been suspended during the epidemic's peak. This study was exempt from IRB review.

A c c e p t e d M a n u s c r i p t

Employees meeting criteria for testing contacted a call center which screened employees for testing eligibility. The request for testing was forwarded through Epic® to a pool of physicians and nurse practitioners who ordered the COVID-19 RT-PCR. Using MyChart, the NYULH patient portal, the employee then scheduled the test at one of NYULH's testing centers.

NYULH developed three testing centers in former conference rooms, building testing cubicles for specimen collection that were under negative pressure. Samples were obtained by nurses in PPE (N95 respirators, face shields, and impermeable gowns). Nasopharyngeal samples were obtained by inserting a swab into the anterior nares until reaching the nasopharynx and rotating the swab for several seconds. Samples were placed in tubes containing Viral Transport Medium and were submitted to the hospital laboratory.

Detection of SARS-CoV-2 RNA using real time RT-PCR was performed on the Roche fully automated Cobas 6800 system under Emergency Use Authorization. Results were reported as detected (positive) or not detected (negative).

The SARS-CoV-2 results interfaced into Epic® and were automatically released to employees through MyChart. Simultaneously, employee RT-PCR results returned to the ordering-provider pool. Positivity rates amongst all groups of employees being tested including symptomatic employees, asymptomatic employees with self-reported exposure to COVID-19, and employees being screened for returning work declined over time ( Figure 1 ). Overall, for symptomatic employees, the positivity rate was 33%, but the positivity rate declined from 51% in the first week of testing (March 25-March 31) to 3% in the most recent week of testing starting May 13 th . The overall positivity rate of asymptomatic employees with self-reported exposures was 8%, dropping from 12% in the first week of testing (April 1-April 7) to 0% during the most recent week of testing starting May 13th. All asymptomatic staff who were returning to work in re-opening services were tested starting on April 20th had a mean positivity rate of 3% (Figure 1 ). In the first week of testing 5% of these employees were positive, but in the most recent week of testing 0% were positive.

A c c e p t e d M a n u s c r i p t

HCW are at increased risk for exposure to persons with COVID-19. NYULH began a dedicated, ondemand COVID-19 diagnostic program for employees in late March 2020. Over the following eight weeks, nearly 15,000 symptomatic and asymptomatic employees were tested. Testing results were used to guide treatment, self-isolation, and to reinforce the rigorous PPE standards used during COVID-patient care.

This comprehensive testing program helped to maintain and manage the workforce. Even amongst the symptomatic employees, over 67%of those tested were COVID-19 negative, enabling these workers to go back to work after being fever-free for 72-hours rather than being isolated for a minimum of 7-10 days. Similarly, in one British study, 87% of the 1,654 symptomatic HCW tested were negative and were able to return to work more quickly. [6] Thus, in addition to providing comfort and reassurance to employees who test negative, broad testing programs help to maintain the workforce.

Testing of employees and patients is also a critical step to safely re-open essential non-COVID clinical services. Staff and patients want reassurance that healthcare systems are taking all possible steps to exclude persons with active infection from the healthcare environment. While COVID-free environments simply cannot be guaranteed, our goal is to use all current tools, including diagnostic COVID-19 testing for patients and staff, daily symptomatic checks, and mandatory use of PPE in all clinical settings, to minimize exposure to COVID for staff and patients. While, in the future, we expect that COVID antibody testing will be utilized within the healthcare work force; currently antibody testing is not being employed at NYULH as antibody status does not influence or change our policy for patients or staff.

Widespread community transmission existed in metropolitan New York starting in mid-March.

Although the NYULH COVID-19 patient census peaked in early April, throughout the duration of the NYULH employee testing program, the COVID patient census remained consistently greater than 500 and the vast majority of the care delivered at NYULH was direct COVID-19 patient care. Thus during this testing program, most NYULH employees had continued exposure to COVID patients, yet A c c e p t e d M a n u s c r i p t employees still demonstrated sharp declines in COVID infection rates. PPE and infection control standards and procedures are unlikely to account for this decline as they remained comprehensive, stringent, and largely unchanged since the onset of the pandemic in early March. Notably, however, the reduction in employee COVID positive rates is coincident with the decline in New York City cases that began after peaking on April 6 th . [7] The temporal correlation between the reduction in community cases and HCW COVID infections despite continued COVID workplace exposures may suggest the impact of community transmission on the HCW COVID infection rate and the effectiveness of properly donned PPE. The importance of PPE in effectively preventing HCW infections was further evidenced in the New York State testing data released by Governor Cuomo showing that 12.2% of HCW tested positive for COVID antibodies as compared to 19.9% of the approximately 3,000 randomly tested individuals from the general New York City population. [8] Additional studies are needed to be better understand the relative impact of community and workplace exposures to COVID-19 in HCW.

We have shown that widespread testing can be developed and operationalized in a large academic hospital that simultaneously has large patient demands for testing. Employee testing is critical for workforce planning since COVID-19 positive employees require home-isolation for 10 days. Testing combined with conventional infection control measures, supports the culture of safety for patients and workers. Importantly, widespread testing of HCW offers valuable information for hospital workflow and workforce amid an epidemic that threatened to overwhelm the healthcare system. 

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