WARNING! American Study Shows That SARS-CoV-2 Can Remain Infectious For Up To 21 Days On Various Refrigerated Deli Food, Meats And Fresh Produce!
: During the initial stages of the COVID-19 pandemic, as usual we had a lot of ignorant researchers, doctors and authorities trying to act smart and gave public comments that the SARS-CoV-2 virus was not transmissible by foods or that the virus could not remain active for long on food items etc.
However, as time when by, emerging studies showed otherwise coupled with case reports and incidences.
A new comprehensive study conducted by scientists from the Virginia Polytechnic Institute & State University-USA has found that the SARS-CoV-2 coronavirus can in fact remain infectious on a variety of refrigerated deli food, meats and fresh produce for up to 21 days!
Importantly it should also be noted that the SARS-CoV-2 coronavirus that causes COVID-19 can infect oral cavity and intestinal cells.
Hence finding the infectious form of the novel coronavirus on foods and food packaging also suggests that infection could potentially occur following ingestion of virus-contaminated foods.
In order to determine the relative risk of infection from different types of foods, the Foods-SARS-CoV-2
study team assessed survival of SARS-CoV-2 on refrigerated ready-to-eat deli items, fresh produce, and meats (including seafood). Deli items and meats with high protein, fat and moisture, maintained infectivity of SARS-CoV-2 for up to 21 days. However, processed meat, such as salami, and some fresh produce exhibited antiviral effects. SARS-CoV-2 also remained infectious in ground beef cooked rare or medium, but not well-done.
Although infectious SARS-CoV-2 was inactivated on the foods over time, viral RNA was not degraded in similar trends, regardless of food type; thus, PCR-based assays for detection of pathogens on foods only indicate the presence of viral RNA, but do not correlate with presence or quantity of infectious virus.
The survival and high recovery of SARS-CoV-2 on certain foods support the possibility that food contaminated with SARS-CoV-2 could potentially be a source of infection, highlighting the importance of proper food handling and cooking to inactivate any contaminating virus prior to consumption.
The study findings were published in the peer reviewed journal: Foods.
Initially when the COVID-19 disease first emerged, many health authorities and so called ‘experts’ issued advice to their citizens to help them avoid catching the disease such as washing their hands, social distancing, and wearing masks in public but the advice on items entering the household often varied. https://www.thailandmedical.news/news/covid-19-news-who-says-food-safe-fom-sars-cov-2-coronavirus--fake-news-and-misinformation-or-fact
This was especially so most with food shopping and groceries, and many consumers opted to wash every piece of food that entered their house wherever possible. S
ome who were smart and took advice from Thailand Medical News, used ozone water to wash their fresh produce and food items. https://www.thailandmedical.news/news/japanese-study-shows-that-ozone-water-rapidly-inactivates-sars-cov-2-coronavirus,-making-it-an-ideal-covid-19-disinfectant-and-sanitizer
The study team from the Virginia Polytechnic Institute have been investigating the survival times of the SARS-CoV-2 virus on various foods.
The study team chose to inoculate the surface of food samples with 1x10^4 PFU in multiple droplets, slightly less than the number of copies of SARS-CoV-2 that are generated with a typical cough.
The SARS-CoV-2 virus was recovered immediately after inoculation in order to understand how much virus could be reclaimed from each food. Following this, the virus was incubated for five different lengths of time – 1 hour, 24 hours, 7 days, 14 days and 21 days – at 4C.
Altogether three different types of foods were chosen to represent the standard fare that can be brought from a delicatessen (deli) ie roasted turkey for cooked meats, swiss cheese representing cheeses, and salami for more processed and seasoned meat.
The SARS-CoV-2 virus on the turkey showed no significant reduction until day 7, and infectious virus could be recovered from the turkey for the full length of the study. The virus that could be recovered from the cheese had been significantly reduced by 24 hrs, but like the turkey SARS-CoV-2 was still present and infectious at the end of the study. Salami showed far more rapid reduction in viral levels, with the concentration reduced 2 log by 24hr, and completely absent by day 14.
Subsequently, the study team selected items that are often consumed raw such as tomatoes, grapes, and avocado (both shell and pulp).
Tomatoes and grapes displayed a very similar pattern, with the levels of virus present remaining consistent until day 7, before steadily reducing by over 2 log by day 14. However, infectious levels of the virus were still present at day 21!
However, the SARS-CoV-2 virus did not survive very well on the avocado shell, with levels dropping consistently until they were undetectable on day 14 and it survived even worse on the avocado pulp, dropping below the level of detection by the seventh day.
Next, the study team tested meats such as raw beef steak and pork chops, ground beef and pork, a plant-based meat alternative and oysters.
Unfortunately, the virus survived extremely well on almost all samples. The pork chops and ground pork showed the least reduction in viral levels, with consistently high survival throughout the study. The beef steak, ground beef and plant-based meat alternative all supported the virus until day 14, and could still be recovered from the oysters by day 21.
In the west as most people tend to cook meat before consuming it, the study team then tested the survival of SARS-CoV-2 following its inoculation into beef patties that were then cooked to three different temperatures mimicking rare (51.2C), medium (62.5C) and well-done (71.7C) temperatures.
As expected, the higher temperatures killed the virus better, with no recoverable viable virus present on the well-cooked burger. However, infectious viruses could be recovered from the other two patties ie medium and rare, potentially indicating that they could carry risk of infection.
It should be noted that in many East Asian and South-East Asian countries, many individuals still prepare dishes that use uncooked meat such as in spicy salads etc including countries like China, Myanmar, Vietnam, Cambodia, Laos and Thailand.
In order to help other scientists compare these results to more common methods of pathogen detection (swabbing, nucleic acid extraction and PCR assays), the study team selected eight foods to represent the three different categories and performed qRT-PCR assays to determine the viral genome copy number at two different incubation points, immediately following incubation and the first incubation time that showed at least a 1 log reduction in viral titre.
This was 24 hours for avocado pulp, 7 days for ground beef, the plant-based alternative and oysters, and 14 days for tomatoes and grapes. As the avocado pulp was effective at reducing the viral titre significantly immediately, the researchers chose the time points of 0 hours and 24hours.
The study team found that the RNA copy was normally 2-3 times higher than the infectious viral titre - although the two results were not always directly consistent.
The study findings have successfully shown the effective lengths at which SARS-CoV-2 can survive on certain foods, which can likely act as a model to predict how well it could survive on many others.
The study findings could help consumers decide how best to protect themselves when purchasing and eating food and could help inform supermarkets, grocers and other companies that sell food, helping them avoid spreading the disease.
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