Study determines SARS-CoV-2 viability in food at different temperatures

Recent food microbiology A study in the journal explores survival of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in food and potential treatments to inactivate the virus from these products.

study: SARS-CoV-2 viability in lettuce, chicken, and salmon and inactivation by peracetic acid, ethanol, and chlorine dioxide. Image credit: AstroStar / Shutterstock.com

Background

SARS-CoV-2, the causative agent of the coronavirus disease 2019 (COVID-19) pandemic, is a betacoronavirus that is primarily spread through respiratory droplets and aerosols.

A seafood market in Wuhan, China, is believed to be the original source of SARS-CoV-2. About 55% of his COVID-19 cases in China detected in December 2019 were linked to this market.

Several studies have linked virus-contaminated frozen food and food packaging with other COVID-19 outbreaks. These observations have raised global concerns about food safety during the pandemic.

In the current study, scientists are evaluating SARS-CoV-2 viability on three foodstuffs stored at different temperatures. They also determine the potency of the three disinfectants in inactivating viruses in food.

research design

Three foods were selected for viral viability testing: lettuce, chicken, and salmon. Food was then contaminated with SARS-CoV-2 and stored at 20 °C (room temperature), 4 °C (refrigerated), and -40 °C (frozen).

Food-grade ethanol, chlorine dioxide, and peracetic acid were selected as disinfectants for virus inactivation studies. Except for ethanol, which was used at concentrations of 30%, 50%, and 70%, two other disinfectants were used at three different concentrations, including the recommended concentration and half and double the recommended concentration.

SARS-CoV-2 viability in food

The lowest viability of SARS-CoV-2 on food was at room temperature. After 48 hours of contamination, no detectable virus titers were obtained in any food. followed.

A significant induction of viability was observed at 4 °C. The highest survival rate was observed at 4 °C in salmon, where SARS-CoV-2 remained infective for up to 14 days after contamination. In lettuce and chicken, SARS-CoV-2 was detectable for up to 10 days.

A 5- to 9-fold induction of viral half-life was observed at 4 °C compared to that observed at room temperature. Salmon has the longest half-life, followed by chicken and lettuce.

At freezing temperatures, SARS-CoV-2 remained viable in tested foods for up to 4 weeks. A significant induction of viral half-life over her 30-fold was also observed with each food.

Inactivation of SARS-CoV-2 by disinfectants

A brief 1-minute exposure to 70% ethanol effectively inactivated SARS-CoV-2 in lettuce, but not in chicken and salmon. Inactivation of chicken and salmon viruses was observed after exposure to 70% ethanol for 5 minutes.

For chlorine dioxide, no significant virus-inactivating effect was observed at all concentrations and exposure durations tested. At the highest concentration and exposure time, chlorine dioxide was found to reduce viral infectivity to a certain level only in lettuce.

In contrast to chlorine dioxide, peracetic acid showed significantly higher potency in inactivating SARS-CoV-2 in food. Specifically, peracetic acid completely inactivated the virus at twice the recommended concentration for each food tested.

Significance of research

The results of this study show that the viability of SARS-CoV-2 on food increases more than 30-fold at freezing temperatures compared to room temperature. In addition to storage temperature, virus survival also depends on food type.

Two virus variants are studied here, including SARS-CoV-2 S and SARS-CoV-2 L. SARS-CoV-2 L has shown a higher survival rate in food than SARS-CoV-2 S. A highly effective disinfectant capable of completely inactivating both virus variants in food.

The highest potency of peracetic acid was observed at twice the recommended concentration. However, no antiviral effects of chlorine-based disinfectants were observed in this study.