Viability of SARS-CoV-2 on lettuce, chicken, and salmon and its inactivation by peracetic acid, ethanol, and chlorine dioxide

Abstract

Since the first SARS-CoV-2 outbreak in Wuhan, China, there has been continued concern over the link between SARS-CoV-2 transmission and food. However, there are few studies on the viability and removal of SARS-CoV-2 contaminating food. This study aimed to evaluate the viability of SARS-CoV-2 on food matrices, depending on storage temperature, and inactivate the virus contaminating food using disinfectants. Two SARS-CoV-2 strains (L and S types) were used to contaminate lettuce, chicken, and salmon, which were then stored at 20,4 and -40 °C. The half-life of SARS-CoV-2 at 20 °C was 3-7 h but increased to 24-46 h at 4 °C and exceeded 100 h at -40 °C. SARS-CoV-2 persisted longer on chicken or salmon than on lettuce. Treatment with 70% ethanol for 1 min inactivated 3.25 log reduction of SARS-CoV-2 inoculated on lettuce but not on chicken and salmon. ClO2 inactivated up to 2 log reduction of SARS-CoV-2 on foods. Peracetic acid was able to eliminate SARS-CoV-2 from all foods. The virucidal effect of all disinfectants used in this study did not differ between the two SARS-CoV-2 strains; therefore, they could also be effective against other SARS-CoV-2 variants. This study demonstrated that the viability of SARS-CoV-2 can be extended at 4 and -40 °C and peracetic acid can inactivate SARS-CoV-2 on food matrices.

Keywords: Beef; Chlorine dioxide; Ethanol; Lettuce; Peracetic acid; SARS-CoV-2; Salmon; Viability.

Graphical abstract

Fig. 1

Viability of SARS-CoV-2 on food matrices at 20 °C. (A) Virus titer recovered from the surface by timepoint. (B) Bayesian regression plots showing the predicted decay of virus titers over time. The dots are slightly jittered to avoid overlapping. Lines show exponential decay rates and were randomly drawn at 150 per panel from the joint posterior distribution. (C) Violin plot representing the half-life of viruses. The dots represent the median estimates, and the lines are the 95% confidence intervals. The dashed lines in (A) and (B) indicate the limit of detection. Asterisks indicate statistical significance (*p < 0.05, **p < 0.01, ***p < 0.005).

Fig. 2

Viability of SARS-CoV-2 on food matrices at 4 °C. (A) Virus titers recovered from the surface by timepoint. (B) Bayesian regression plots showing the predicted decay of virus titers over time. The dots are slightly jittered to avoid overlapping. Lines show exponential decay rates and were randomly drawn at 150 per panel from the joint posterior distribution. (C) Violin plot representing the half-life of viruses. The dots represent the median estimates, and the lines are the 95% confidence intervals. The dashed lines in (A) and (B) indicate the limit of detection. Asterisks indicate statistical significance (*p < 0.05, **p < 0.01, ***p < 0.005).

Fig. 3

Viability of SARS-CoV-2 on food matrices at −40 °C. (A) Virus titers recovered from the surface by timepoint. (B) Bayesian regression plots showing the predicted decay of virus titers over time. The dots are slightly jittered to avoid overlapping. Lines show exponential decay rates and were randomly drawn at 150 per panel from the joint posterior distribution. (C) Violin plot representing the half-life of viruses. The dots represent the median estimates, and the lines represent the 95% confidence intervals. The dashed lines in (A) and (B) indicate the limit of detection. Asterisks indicate statistical significance (*p < 0.05, **p < 0.01, ***p < 0.005).

Fig. 4

Virucidal effect of ethanol against SARS-CoV-2 contaminating food matrices. The dashed line indicates the limit of detection at 0.5 TCID₅₀/mL for lettuce and 1.5 TCID₅₀/mL for chicken and salmon. Lowercase letters indicate significant difference between the disinfectant treated group and the control within the same virus strain (p < 0.05). EtOH, ethanol.

Fig. 5

Virucidal effect of sodium hypochlorite against SARS-CoV-2 contaminating food matrices. The dashed line indicates the limit of detection at 0.5 TCID₅₀/mL for lettuce and 1.5 TCID₅₀/mL for chicken and salmon. Lowercase letters indicate significant difference between the disinfectant treated group and the control within the same virus strain (p < 0.05). ClO₂, Chlorine dioxide.

Fig. 6

Virucidal effect of peracetic acid against SARS-CoV-2 contaminating food matrices. The dashed line indicates the limit of detection at 0.5 TCID₅₀/mL for lettuce and 1.5 TCID₅₀/mL for chicken and salmon. Lowercase letters indicate significant difference between the disinfectant treated group and the control within the same virus strain (p < 0.05). PAA, peracetic acid.