Detection of air and surface contamination by SARS-CoV-2 in hospital rooms of infected patients

Po Ying Chia,Jun Yang Tay,Boon Huan Tan,Ray Junhao Lin,Isais Florante Santos,David Chien Lye,Chen Seong Wong,Glorijoy Shi En Tan,Sapna Sadarangani,Cheng Chuan Lee,Deborah Hee Ling Ng,Chiaw Yee Choy,Yu Kit Chan,Poh Lian Lim,Jackie Yu-Ling Tan,Frederico Dimatatac,Pei Hua Lee,Chi Jong Go,Lawrence Lee,Shehara Mendis,Nihar Pandit,Yuan Yi Constance Chen,Ai Sim Lim,Tsin Wen Yeo,Than The Son,Mohammad Yazid Abdad,Benjamin Choon Heng Ho,Tau Hong Lee,Michelle Wong ,Stephanie Sutjipto,Donald K Milton,Sean Wei Xiang Ong,Sok Kiang Lau,Yian Kim Tan,Marcus Gum,Mucheli Sharavan Sadasiv ,Mónica Chan ,Shawn Vasoo,Xiao Fang Lim,Brenda Ang ,Kristen K Coleman ,Gregory C Gray,Li L ,Oon Tek Ng ,Barnaby Edward Young,Yee‐Sin Leo ,Stephan C Schuster ,Partha Pratim De,Timothy Barkham,D G Moses ,Kalisvar Marimuthu

doi:10.1038/s41467-020-16670-2

Abstract

Understanding the particle size distribution in the air and patterns of environmental contamination of SARS-CoV-2 is essential for infection prevention policies. Here we screen surface and air samples from hospital rooms of COVID-19 patients for SARS-CoV-2 RNA. Environmental sampling is conducted in three airborne infection isolation rooms (AIIRs) in the ICU and 27 AIIRs in the general ward. 245 surface samples are collected. 56.7% of rooms have at least one environmental surface contaminated. High touch surface contamination is shown in ten (66.7%) out of 15 patients in the first week of illness, and three (20%) beyond the first week of illness (p = 0.01, χ2 test). Air sampling is performed in three of the 27 AIIRs in the general ward, and detects SARS-CoV-2 PCR-positive particles of sizes >4 µm and 1–4 µm in two rooms, despite these rooms having 12 air changes per hour. This warrants further study of the airborne transmission potential of SARS-CoV-2.

Highlights

Understanding the particle size distribution in the air and patterns of environmental contamination of SARS-CoV-2 is essential for infection prevention policies
Environmental sampling was conducted in three airborne infection isolation rooms (AIIRs) in the ICU and 27 AIIRs in the general ward
Surface sampling revealed that the polymerase chain reaction (PCR)-positivity high-touch surfaces was associated with nasopharyngeal viral loads and peaked at approximately day 4–5 of symptoms

Summary

Introduction

Understanding the particle size distribution in the air and patterns of environmental contamination of SARS-CoV-2 is essential for infection prevention policies. Air sampling is performed in three of the 27 AIIRs in the general ward, and detects SARS-CoV-2 PCR-positive particles of sizes >4 μm and 1–4 μm in two rooms, despite these rooms having 12 air changes per hour. This warrants further study of the airborne transmission potential of SARS-CoV-2. The primary objective of our study is to identify potential patient-level risk factors for environmental contamination by SARS-CoV-2 by sampling the air and surfaces surrounding hospitalized COVID-19 patients at different stages of illness

Objectives

Methods

Results

Conclusion