Analysis of COVID-19 Virus Particles on Surfaces in New York City

Abstract

Purpose : SARS-CoV-2 virus can remain stable on surfaces for several days. This cross-sectional analysis sought to determine the presence of SARS-CoV-2 virus on various surfaces that trainees and faculty of an academic eye clinic routinely came into contact with during the pandemic in New York City.

Methods : Samples were collected by faculty and trainees from surfaces encountered during daily life. On 4 different days, teams collected at least two samples using sterile swabs (Puritan HydraFlock). Prior to collection, nasal swabs were obtained from all individuals to check for SARS-CoV-2. Collection sites were grouped into four zones depending on proximity and the amount of the time personnel spent there. Zones included: (1) Work microenvironment: Slit lamp; door handles; computers; waiting room; reception; bathrooms (2) Work macroenvironment: ICU, ED, inpatient units; elevators, bathrooms; cafeteria (3) Living microenvironment: Home doorknob; kitchen; car; sitting area (4) Living macroenvironment: Subway station; subway cars; car services; restaurants; bike stations; grocery stores. Samples were transported to the lab in transport medium and RNA extraction was conducted using the QIAamp DSP Viral RNA Mini Kit. Presence of viral RNA was investigated using Luna Universal Probe One-step RT–qPCR.

Results : A total of 816 swabs were submitted. Only 2 (0.25%) samples were positive. The first was a sample from a patient bathroom sink handle in the main emergency room and the second was a nasal swab from a staff member who had been assigned to collect samples. Prior to this positive swab result, this staff member had tested positive for COVID-19, quarantined for two weeks, and had then received one prior negative test.

Conclusions : Though COVID-19 is currently widespread in the United States, this study shows that the healthcare personnel working in New York City at Edward S. Harkness Eye Institute at the Columbia University Irving Medical Center have a low chance of encountering viral RNA on surfaces they are in close contact with during their daily life. Considering the 1.77-2.39% citywide test positivity during the time this study was conducted, the likelihood of faculty and trainees getting infected from contaminated surfaces is 100 times less likely than acquiring COVID-19 from an infected individual. This result may be a reflection of the efficacy of disinfection protocols or the limited viability of the virus on inorganic surfaces.

This is a 2021 ARVO Annual Meeting abstract.