Factors affecting stability and infectivity of SARS-CoV-2

J Hosp Infect. 2020 Oct;106(2):226-231. doi: 10.1016/j.jhin.2020.07.009. Epub 2020 Jul 9.

Abstract

Background: In late 2019, a novel human coronavirus - severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) - emerged in Wuhan, China. This virus has caused a global pandemic involving more than 200 countries. SARS-CoV-2 is highly adapted to humans and readily transmits from person-to-person.

Aim: To investigate the infectivity of SARS-CoV-2 under various environmental and pH conditions. The efficacies of various laboratory virus inactivation methods and home disinfectants against SARS-CoV-2 were investigated.

Methods: The residual virus in dried form or in solution was titrated on to Vero E6 cells on days 0, 1, 3, 5 and 7 after incubation at different temperatures. Viral viability was determined after treatment with various disinfectants and pH solutions at room temperature (20-25oC).

Findings: SARS-CoV-2 was able to retain viability for 3-5 days in dried form or 7 days in solution at room temperature. SARS-CoV-2 could be detected under a wide range of pH conditions from pH 4 to pH 11 for several days, and for 1-2 days in stool at room temperature but lost 5 logs of infectivity. A variety of commonly used disinfectants and laboratory inactivation procedures were found to reduce viral viability effectively.

Conclusion: This study demonstrated the stability of SARS-CoV-2 on environmental surfaces, and raises the possibility of faecal-oral transmission. Commonly used fixatives, nucleic acid extraction methods and heat inactivation were found to reduce viral infectivity significantly, which could ensure hospital and laboratory safety during the SARS-CoV-2 pandemic.

Keywords: High infection rate; Infectivity; Route of transmission; SARS-CoV-2; Stability.

MeSH terms

  • Betacoronavirus / growth & development*
  • Betacoronavirus / pathogenicity*
  • COVID-19
  • China / epidemiology
  • Coronavirus Infections / epidemiology
  • Coronavirus Infections / physiopathology*
  • Humans
  • Microbial Viability*
  • Pandemics
  • Pneumonia, Viral / epidemiology
  • Pneumonia, Viral / physiopathology*
  • SARS-CoV-2
  • Severe Acute Respiratory Syndrome / epidemiology
  • Severe Acute Respiratory Syndrome / pathology*
  • Virulence*
  • Virus Inactivation*