SARS-CoV-2 persistence on common food covering materials: plastic wrap, fruit wax, and cardboard takeout containers.

Aims: Assess the persistence of infectious SARS-CoV-2 virus and virus genomic material on three common food coverings.
Methods and Results: The stability of infectious virus and genomic material on plastic wrap, fruit wax, and cardboard takeout containers was measured. SARS-CoV-2 in simulated saliva was applied to the surface of these materials and allowed to dry. Samples were stored at 4°C or 20°C and a relative humidity of 30%, 50%, 65%, or 70% for up to 7 days. Viability was measured by TCID50 and the half-life for infectious virus was determined to be ~24 hours and ~8 hours at 4°C and 20°C, respectively, on all surfaces and RH tested. There was no loss of virus genomic material as measured by qRT-PCR at all conditions evaluated.
Conclusions: SARS-CoV-2 virus remains infectious on food coverings for hours to days. It is estimated that a 99.9% reduction in titer requires 10 days at 4°C and 3 days at 20°C for all RH tested. SARS-CoV-2 genomic material showed no loss when assayed by qRT-PCR. Significance and Impact of Study: SARS-CoV-2 virus on food coverings loses infectivity over a certain period, but PCR assays can still detect virus genomic material throughout the same time. Thus, testing and controls may need to consider the fact that virus genomic material may still be detected when no infectious virus is present.
(© The Author(s) 2022. Published by Oxford University Press on behalf of Applied Microbiology International.)