Detection and infectivity potential of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) environmental contamination in isolation units and quarantine facilities

Abstract

Objectives: Environmental surfaces have been suggested as likely contributors in the transmission of COVID-19. This study assessed the infectivity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) contaminating surfaces and objects in two hospital isolation units and a quarantine hotel. Methods: SARS-CoV-2 virus stability and infectivity on non-porous surfaces was tested under controlled laboratory conditions. Surface and air sampling were conducted at two COVID-19 isolation units and in a quarantine hotel. Viral RNA was detected by RT-PCR and infectivity was assessed by VERO E6 CPE test. Results: In laboratory-controlled conditions, SARS-CoV-2 gradually lost its infectivity completely by day 4 at ambient temperature, and the decay rate of viral viability on surfaces directly correlated with increase in temperature. Viral RNA was detected in 29/55 surface samples (52.7%) and 16/42 surface samples (38%) from the surroundings of symptomatic COVID-19 patients in isolation units of two hospitals and in a quarantine hotel for asymptomatic and very mild COVID-19 patients. None of the surface and air samples from the three sites (0/97) were found to contain infectious titres of SARS-Cov-2 on tissue culture assay. Conclusions: Despite prolonged viability of SARS-CoV-2 under laboratory-controlled conditions, uncultivable viral contamination of inanimate surfaces might suggest low feasibility for indirect fomite transmission.

Earliest detection to date of SARS-CoV-2 in Florida: Identification together with influenza virus on the main entry door of a university building, February 2020

“…We hypothesize that the door handle sampled in our study was contaminated with SARS-CoV-2 by an asymptomatic or mildly symptomatic individual who initially acquired the infection in Seattle (or, possibly, in China) and then traveled to the University. In keeping with the observation that viability/transmissibility of SARS-CoV-2 on surfaces may be limited [ 20 , 21 ], we did not see evidence that the SARS-CoV-2 strain identified was the basis for subsequent emergence and spread of COVID-19 in our region. Instead, our data are consistent with multiple local introductions of SARS-CoV-2 from different countries/regions, as reflected in the divergence of sequences seen among our UF strains.…”

“…However, when SARS-CoV-2 was placed on a surface in a solution containing bovine serum albumin (BSA) at a concentration of 10 g/l, intended to mimic the concentration of protein found in respiratory secretions, the decline was much slower, with a half-life of >96 hours [ 18 ]. In hospital-based studies, reported rates of surface contamination within COVID-19 patient rooms (based on detection by PCR) vary widely: in one study, SARS-CoV-2 viral RNA was detected on 29 (51%) of 55 surface samples, although investigators were not able to culture the virus from any of these samples [ 20 ]. In a second study, only 3 of 22 surface samples tested positive for SARS-CoV-2 RNA [ 21 ].…”

SARS-CoV-2 detection and genomic sequencing from hospital surface samples collected at UC Davis

“…This probably explains otherwise surprising results such as the lack of viral RNA detected in an oncology ward housing patients with COVID-19 (24), or the very low probability of detection in an ICU (25). Several studies detected SARS-CoV-2 RNA in these environments but were unable to culture infectious SARS-CoV-2 virions (26)(27)(28).…”

SARS-CoV-2 Airborne Surveillance Using Non-Powered Cold Traps

“…10 Samples were collected on styrene filter cassettes followed by a two-step RT-PCR protocol using digital droplet PCR (ddPCR). Other studies demonstrated viable SARS-CoV-2 in single hospital rooms of infected patients 11,12 and in isolation units 13 collected by bioaerosol samplers. Moreover, Nissen et al 14 were able to detect SARS-CoV-2 RNA in central ventilation systems distant from patient indicating that airborne SARS-CoV-2 can be transported over long distances.…”

“…10 Samples were collected on styrene filter cassettes followed by a two-step RT-PCR protocol using digital droplet PCR (ddPCR). Other studies demonstrated viable SARS-CoV-2 in single hospital rooms of infected patients 11,12 and in isolation units 13 collected by . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.…”