This is a question I’m getting asked a lot, and I’m a bit concerned at the extreme examples of people ‘cleaning’ their entire shop when they get home - which can actually be more dangerous than doing nothing!
Before we all start scrubbing away at our chicken kievs, or giving our oranges a bubble bath – let’s consider the actual infection risk posed by food, and how improper washing of your food might actually increase your chances of getting sick.
As always, if we all behave responsibly and follow government advice, the risk of infection is reduced for everyone, so please stick to these!
Could viruses be on my food shopping?
There is very little research on whether viruses are present on food or packaging (most virologists are currently a little pre-occupied with finding treatments!). At time of writing, the FDA have reported no evidence of virus transmission via food or food packaging.
There have been a few preliminary studies on how long the Covid-19 virus lasts on different surfaces and at different temperatures – as we know that the main source of infection (other than being in close contact with an infected person), is touching contaminated surfaces then touching your face/nose.
There is evidence that the virus can last for a short time on paper and cardboard, and much longer on some metals and plastics. In terms of temperature, the Covid-19 virus (like many viruses) is pretty useless at warm temperatures, but is quite stable at 4°C (you can find these two studies here and here).
Though this may appear worrying on the face of it, there are some important things to consider:
Firstly, viruses really hate changes in temperature, and high temperatures. It may seem shocking that viruses can last so long in the fridge, but if you then heat that food up, the virus will be destroyed very quickly.
It’s also important to note these studies aren’t designed to give us insight into everyday life – they are to inform other scientists on how to best handle, store, and decontaminate the virus. These experiments would have been done in highly controlled laboratory environments - very different situations to a kitchen or supermarket.
These studies used really high quantities of virus – much higher than a person could feasibly produce via a cough or sneeze, or even from an invasive swab.
So to summarise, it’s mostly good news. It’s highly unlikely that your food has virus on it. The bad news is – it still might do, it’s all down to chance, we just don’t know where our food has been before we pick it up.
But before you go and dunk all of your shopping in the tub, let’s think about the risks of doing that.
Remember that there are other bugs on your food you need to be aware of
Despite being in the midst of a pandemic, other illnesses still exist!
I asked my good friend, and Bacteriologist, Dr Chris Randall, to give us some insight on the risk of bacterial infections when washing your food:
“The problem we have with food is that it can be contaminated with a number of disease causing bacteria. Fruit and vegetables can harbour bacteria such as E. coli, and raw poultry can be contaminated with Campylobacter, both of which can cause severe food poisoning.
Viruses can be destroyed by normal soap and water, however, bacteria are much hardier and can easily withstand a bit of soap (some are even resistant to alcohol!), so when you are washing your food you could end up just splattering live bacteria all over your kitchen surfaces. Even worse, if you decide to wash different foods all at the same time or in the same water, you are most likely just spreading any bacteria from one contaminated item to all of your food.
So what is the best way to protect yourself from Covid-19 without accidentally giving everyone food-poisoning? Use standard kitchen hygiene:
With fruit or vegetables which you plan on eating raw remove any lingering soil so give them a good rub under running water in the sink, trying to avoid any splatter
For raw meat the cooking process will inactivate any bacteria or viruses present. But it is still important to prepare raw meat away from other foods, using separate chopping boards, knives and utensils.
Importantly, wash your hands! Wash before preparing food, after washing your fruit and veg, after handling raw meat, and wash again before eating”
The main risk of infection from food shopping is not the food we buy – it’s our behaviour
It is important to remember that, unless you are in regular, close contact with an infected individual, the main risk of infection is contacting contaminated surfaces with your hands, then touching your face, or being sneezed/coughed on by an infected individual.
Think about the number of surfaces you touch in a supermarket – handles of fridges/freezes, trolleys, the items you pick up, shelves, baskets, card machines etc. Any of these surfaces could have touched by an infected individual – we have no way of knowing who touched these things before us.
This is why following Government advice when doing your shop is the best way to reduce the risk to ourselves and others around us:
If you are sick (or have been exposed to someone who is) stay at home
Wash your hands before and after going to the supermarket (remember, we should treat everyone, including yourself, as potentially infectious as you may be infected but not have symptoms yet)
Avoid touching your face
Stay 2 metres / 6 feet away from others
In addition when in the supermarket, I recommend:
Only pick up items you intend to purchase
Try to reduce the number of surfaces you touch - only touch what you need to
Try and limit the number of trips to the shops
So to summarise….
As always, think of others around you, stay sensible, stay safe, and wash your hands!
And finally
Thanks for reading! If you have any specific questions that you think I might be able to help with, then please do get in touch! I’m trying to tackle subjects that are causing concern or confusion, so knowing what people are unsure about is really helpful for giving me direction, as well as (hopefully) giving everyone some sensible advice.