Stability and inactivation of SARS-CoV-2 on food contact surfaces

Abstract

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has infected more than 269 million people and killed more than 5.3 million people worldwide. Although fomite transmission of SARS-CoV-2 has been continuously reported, few studies have been conducted on food contact surfaces. Therefore, this study aimed to investigate the viability of coronaviruses on food contact surfaces and to remove SARS-CoV-2 contaminated on food contact surfaces with disinfectants. At 20 °C, SARS-CoV-2 was inactivated within 48 h on all food contact surfaces. At 4 °C, it was inactivated at 48 h on kraft paper and 96 h on parchment paper, but it was viable up to 5 days in low-density polyethylene (LDPE). At -20 °C, SARS-CoV-2 did not decrease by even 1 log on all food contact surfaces until 5 days. Treatment with 70% ethanol or 1000 ppm sodium hypochlorite for 5 min was sufficient to completely remove SARS-CoV-2 from 6 food contact surfaces. Similarly, UV-C irradiation at 60 mJ/cm² eliminated SARS-CoV-2 contaminated on food contact surfaces. Also, the wiping test showed that even wiping an area contaminated with SARS-CoV-2 with a cloth moistened with 70% ethanol or 1000 ppm sodium hypochlorite, it took 5 min to inactivate the virus. Our findings suggested that SARS-CoV-2 contaminated on food contact surfaces in local retail may be viable enough to be transported home. However, if the type and method of use of the disinfectant suggested in this study are followed, it is possible to sufficiently control the fomite transmission of SARS-CoV-2 through food contact surfaces at home.

Keywords: COVID-19; Food contact surface; Quantitative carrier test; Viability; Wiping test.

Fig. 1

Viability of coronaviruses on food packaging surface at 20 °C. (A) Titer of virus 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 150 per panel from the joint posterior distribution. (C) Violin plot representing the half-life of viruses. The dot are the median estimates, and the lines are the 95% confidence intervals. The dashed line in (A) and (B) indicates the limit of detection.

Fig. 2

Viability of coronaviruses on food packaging surface at 4 °C. (A) Titer of virus 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 150 per panel from the joint posterior distribution. (C) Violin plot representing the half-life of viruses. The dot are the median estimates, and the lines are the 95% confidence intervals. The dashed line in (A) and (B) indicates the limit of detection.

Fig. 3

Viability of coronaviruses on food packaging surface at −20°C. (A) Titer of virus 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 150 per panel from the joint posterior distribution. (C) Violin plot representing the half-life of viruses. The dot are the median estimates, and the lines are the 95% confidence intervals. The dashed line in (A) and (B) indicates the limit of detection.

Fig. 4

Virucidal effect of ethanol against coronaviruses that contaminated food contact surfaces. The dashed line indicates the limit of detection. Asterisks indicate statistical significance (*p < 0.05, **p < 0.01, ***p < 0.005, ****p < 0.001).

Fig. 5

Virucidal effect of sodium hypochlorite against coronaviruses that contaminated food contact surfaces. The dashed line indicates the limit of detection. Asterisks indicate statistical significance (*p < 0.05, **p < 0.01, ***p < 0.005, ****p < 0.001).

Fig. 6

Virucidal effect of UV-C against coronaviruses that contaminated food contact surfaces. The dashed line indicates the limit of detection. Asterisks indicate statistical significance (*p < 0.05, **p < 0.01, ***p < 0.005, *****p < 0.001).

Fig. 7

Wiping test for inactivation of coronaviruses that contaminated food contact surfaces. The dashed line indicates the limit of detection. Asterisks indicate statistical significance (*p < 0.05, **p < 0.01, ***p < 0.005, ****p < 0.001).