Considering the role of environmental contamination in the spread of COVID-19

March 12, 2020 Jon Otter (@jonotter) COVID-19aerosol, aerosol generating procedures, AGP, coronavirus, FFP3, MERS, SARS, SARS-CoV-1, SARS-CoV-2, surfaces

We know that respiratory viruses can be spread through droplets, occasionally aerosols, and contact routes (see Figure 1). But what is the relative importance of these transmission routes for the SARS-CoV-2 virus, which causes COVID-19? A new pre-print paper published yesterday provides evidence that the stability of the SARS-CoV-2 coronavirus is broadly comparable to the ‘original’ SARS coronavirus (SARS-CoV-1) on dry surfaces and in aerosols. This paper supports an important role for dry surface contamination and aerosols in the spread of SARS-CoV-2, and suggests that improved environmental persistence isn’t the key to the relative success of SARS-CoV-2 over SARS-CoV-1.

Figure 1: Transmission routes of respiratory viruses (from this review article).

The study team tested the ability of the SARS coronavirus (SARS-CoV-1) and the SARS-CoV-2 coronavirus (which causes COVID-19) to survive on a range of dry surfaces (copper, steel, plastic, and cardboard) and in aerosols generated in a drum. Virus survival was broadly comparable between SARS-CoV-1 and -2, with both viruses surviving considerably longer on steel and plastic surfaces than on copper, cardboard, or in aerosols (Figure 2). The half-life of SARS-CoV-2 on plastic was notably high, at around 16 or 17 hours. Even on copper, cardboard, and in aerosols, survival was measured in hours not minutes, and therefore could contribute to transmission.