JOHANNESBURG – As South Africans settle into life amid the loosened restrictions of Alert Level 2, the importance of social distancing, frequent hand washing and the wearing of masks while in public remain at the forefront for preventing the spread of Covid-19.
Over the past six months knowledge about the virus and its effects has increased tenfold, but there remains much that is still unknown about this new disease.
One burning question that keeps resurfacing is whether SARS-CoV-2, the virus causing Covid-19, can be spread by food. Over the past several weeks, for instance, there have been reports of the virus being found in or on food and on seafood packaging imported into China from other countries.
The Chinese authorities have issued warnings to consumers to be careful when purchasing these products, insinuating that such food is unsafe for human consumption and that it could be a source of SARS-CoV-2 infection. The latest product that was reported to have tested positive was imported raw frozen chicken wings.
Current available methods to test for SARS-CoV-2 rely on detecting the presence of viral nucleic acid, or viral RNA. This is the test that was likely used in the case of the latest findings by the Chinese authorities. However, it must be noted that the mere presence of viral RNA does not necessarily mean the presence of active and infectious virus particles, which are required as part of a complex mechanism for infecting human cells.
It is highly unlikely that SARS-CoV-2 is transmitted via food or food packaging as there is still no evidence of such transmission. To date, there have been no reports of transmission of the virus via these routes. Most importantly, one must distinguish between a hazard and a risk. Even if intact virus were present, it does not automatically translate into a risk of transmission via the gastrointestinal (GI) tract. Covid-19 is, therefore, still treated as a respiratory illness and the virus is not regarded as foodborne.
True foodborne viruses are well-documented, for example, the Hepatitis A virus which infiltrates the liver from the GI tract and causes foodborne disease.
It may be possible to contaminate food if an infected worker, for example, coughs or sneezes over that food, or if food is handled with contaminated hands. However, this is not believed to be a primary route of transmission and despite many food products manufactured and consumed globally as well as food packaging handled, there has not been any report of food or food packaging as sources or important transmission routes of the virus causing Covid-19.
Person-to-person transmission, therefore, remains the most important route of infection for this coronavirus. As there is currently no vaccine or noteworthy treatment available, avoiding exposure to the virus is key to preventing potential infection.
Considering that Covid-19 affects the human body primarily via the respiratory route (inhaling droplets or aerosols) and secondarily via soft mucosal tissues, handling raw food and then cross-contaminating to one’s eyes, nose and mouth without washing hands first, remains a possibility, however remote. Nevertheless, this is precisely why maintaining strict hygiene in a kitchen or food-manufacturing environment is key to preventing transfer.
For many decades, good hygiene measures, particularly washing hands after handling any raw product, particularly meat, fish and poultry, have been promoted, and have become part and parcel of safety protocols at food-processing facilities such as abattoirs and meat-processing plants. These practices and others, such as preventing cross-contamination and cooking food thoroughly are simple to implement, yet vital under any circumstances to prevent transmission of any microorganism of public health significance via food.
Therefore, there are currently no foods that should be considered a risk for consumption or warrant consideration as a vector for SARS-CoV-2, as is the case with SARS-CoV-1 and MERS. In the latter two cases, neither virus was transmitted to humans via food.
We are still a year or more from having a readily available vaccine for Covid-19, and until then the prescribed protocols to avoid getting sick remains the widely recommended ones we all know. The silver lining is that is not necessary to worry about getting sick via the food we handle or eat.
Dr Lucia Anelich has a PhD in microbiology and is currently owner of her own food-safety training and consulting business, Anelich Consulting. She is the only South African invited member of the International Commission on the Microbiological Specifications for Food (ICMSF).
Disclaimer: The advice and opinions in this article are voluntary and provided in good faith as guidance by Anelich Consulting. Advice is based on information published by national authorities, public health authorities and scientific research. Anelich Consulting cannot be held liable in any way, for omissions, errors or interpretations, whether in contract, delict, negligence, or otherwise, arising out of this advisory document.