The appearance of the new coronavirus SARS-CoV-2 has put global economies in difficulties causing the confinement of its inhabitants and the suspension of most of the economic activities This historical situation will be known as the “Great Lockdown”.
Despite the main route of transmission is contaminated contact surfaces and respiratory droplets from infected individuals, currently, there is a great concern if the novel SARS-CoV-2 is transmitted through food.
According to organizations like EFSA, Food Stands Agency (UK) or USDA, the likelihood of transmission of the disease COVID19 through food remains as very low but cannot be excluded (1). Currently, there is no evidence that the coronavirus is transmitted through food, and although transmission is basically person-to-person, more studies should be done to rule out this possibility.
What is a virus?
Viruses are infectious particles halfway between living and inert beings composed basically of a nucleic acid genome encased in a protein shell, the capsid. These infectious particles, as simple as successful, have stayed with us since the beginning of the times and although there are many hypotheses about their origin, it is still unknown. (2) Due to its simplicity, viruses need a living host cell to be able to develop and complete their life cycle and to infect other cells, so their life expectancy outside the body is reduced.
Within the wide range of viruses we can find in nature, enteric viruses are major contributors to foodborne disease. These viruses include norovirus, adenovirus, astrovirus, rotavirus, sapovirus and hepatitis A & E viruses. Hepatitis A is associated with more serious illness although, from a foodborne transmission perspective, norovirus is the most important.
Foodborne viruses are transmitted through contaminated food, but also in combination with person-to-person contact or through environmental contamination (cross-contamination faecal-oral). These viruses survive well in the environment, are excreted in abundance in stools. The low infectious dose facilitates spread within a community (only a few viral particles -1 to 100- are needed to cause infection and produce illness). (3)
Are Coronaviruses foodborne viruses?
In 2003, a coronavirus called SARS-CoV ( a related virus with the novel SARS-CoV-2) quickly spread from China to other Asian countries and eventually was brought under control in July 2003. This virus produced an enteric and respiratory disease and probably entered the human population through the preparation and consumption of food of animal origin, particularly civet cats, which contracted the infection from a bat reservoir. Toward the end of March 2003, an outbreak of SARS-CoV occurred among residents of Amoy Gardens, a private housing estate in Hong Kong. A large group of people became infected as a result of faecal spread due to a faulty sewage system. A considerably high proportion of SARS patients from this outbreak had diarrhoeal disease and oral infection. Although it's still unknown if the route of infection in these patients was oral or if they inhaled the virus-containing aerosols, this virus was identified as a virus of primary concern in terms of foodborne transmission. Another study published in April 2020 by Chinese scientists provides evidence of the potential route of SARS-CoV-2 in the digestive system along with the respiratory tract. This study and future researches may have a significant impact on health policy settings regarding the prevention of SARS-CoV-2 infection. (4)
Currently, novel SARS-CoV-2 is not considered an enteric virus, its likelihood of contaminating food is still considered very low and just social distancing and PPE measures are been implemented to stop spreading across the world but considering its phylogenetic proximity of this virus with SARS (it shares around 70-80% of its genome). (5) it should not under any circumstances rule out the potential transmission of the virus through faecal-oral transmission and good practices of hygiene in the food industry should be heavily enforced together with social distancing and protective personal equipment. The possibility of faecal-oral transmission of SARS-CoV-2 has implications, especially in areas with poor sanitation but although still remains unlikely that the virus is transmitted via contaminated food or imported products, general everyday hygiene rules, such as regular hand washing, good temperatures of cooking and hygiene rules for food preparation should be observed when handling them.
(4) Hao Zhang et al., (2020). Digestive system is a potential route of COVID-19: an analysis of single-cell coexpression pattern of key proteins in viral entry process. Accessed 09/05/2020 (5) M. Ceccarelli et al. (2020). Differences and similarities between Severe Acute Respiratory Syndrome (SARS)-CoronaVirus (CoV) and SARS-CoV-2. Would a rose by another name smell as sweet?. Accessed 10/05/2020