Could infectious viral particles be on the parcel that just got delivered? Or the fruit your partner bought home from the supermarket? Or the crosswalk button you pushed out on your daily walk?
Many people are concerned about how the virus could spread, but the good news at this stage is we aren’t seeing any real evidence of transmission from things coming into the home, says virologist Tim Newsome of the University of Sydney.
“If the virus was really infecting people by being on surfaces for days, then we would see much greater spread than what we do see,” Dr Newsome said.
From what the data and contact tracing tells us, the major mode of transmission is still close, sustained contact with an infected person, which is why our social distancing measures have been so effective at flattening the curve.
Virologist Sacha Stelzer-Braid from the University of New South Wales Sydney, agrees that the risk of picking up coronavirus from unpacking your groceries is very low.
But, she said, you may want to take more precautions if you’ve gone into some kind of healthcare setting, or you’ve been somewhere where there was someone coughing.
Here’s what we know about the virus, and some precautions you can follow if you’re concerned.
How long does it stay active on surfaces?
Viruses can live on anything you bring into your home. They can also contaminate any surface if your home that you touch if you have virus particles on your hands when you come home, particularly high use surfaces such as door handles and switches.
“First thing you need to do when you get home is wash your hands, and you can keep surfaces clean,” Dr Newsome said.
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Research published in the New England Journal of Medicine last month, showed this coronavirus can stay viable for up to three days on hard surfaces like stainless steel and plastic.
But it’s also important to remember that doesn’t mean it’s as infectious as when it was first deposited.
“What we see is actually there’s an exponential decay of the virus,” Dr Newsome said.
“It’s not just staying around and then suddenly disappearing at that time, it’s becoming less and less risky over time.”
New research being published in The Lancet Microbe also shows that coronavirus is more stable on smooth surfaces like glass, than on paper, wood or cloth.
But good news is the virus doesn’t tend to stay long on porous surfaces, which are harder to clean, Dr Newsome said.
“Surfaces which are easy to clean, such as plastics and stainless steel, is where the virus is more stable.”
The research also shows while the virus is very stable at 4C, it’s sensitive to higher temperatures.
But that doesn’t mean you need to do anything extra with the food you keep in the fridge or freezer, Dr Stelzer-Braid said.
“It’d probably be the same level of risk as anything else that you buy,” she said.
“If you’ve got a cleaning protocol at your home, and it makes sense to you to wipe things down that you bring back from the shops then I wouldn’t do anything different.”
And it also means you don’t need to worry about catching the coronavirus from food.
What’s the best way to clean surfaces?
“I clean my high touch surfaces once a day … and I just use hot water and detergent for that,” Dr Stelzer-Braid said.
You can also use diluted bleach, or alcohol-based sprays, as the research shows most common disinfectants are quite effective against this virus.
However, she said she can’t recommend eucalyptus oil or tea tree oil until she’s seen actual experimental data of how they go against this virus.
And using the sun can help in your cleaning efforts but it shouldn’t be your only method.
“We do use UV to break up virus but it doesn’t penetrate very far,” Dr Stelzer-Braid said.
“So you can dry your washing in the sun … that’s always a good idea. But I wouldn’t use that as your only way of disinfecting things.”
What other precautions can I take?
“You can change your clothes if you think it’s necessary, and I do because I work in a hospital,” Dr Stelzer-Braid said.
Wash your clothes regularly, and in as hot water as you can, with regular laundry detergent as we know that’s effective at breaking apart this virus.
If you’ve got big, bulky items like winter jackets that are harder to wash regularly, change which one you wear every day, so you’re wearing your jackets on a weekly or three day rotation.
And store your other jackets outside of your house, in the sun if possible.
Dr Stelzer-Braid also removes her shoes when she gets home and leaves them outside the house.
It’s a good idea to wipe down things like your phone, keys and handbag if you can, with either alcohol wipes or hot water and some detergent, Dr Stelzer-Braid said.
What if someone is sick in my house?
If someone in your household becomes sick with COVID-19 you have to be quite vigilant and careful around them.
Dr Stelzer-Braid and co-author Dr Euan Tovey have written guidelines about what to do in that situation.
Along with regular hand washing and routinely cleaning surfaces with water and detergent they recommend:
- Isolating the sick person in a separate room if possible
- If possible they should have their own bathroom, if not, the bathroom should be well ventilated after use, and the surfaces should be considered as contaminated
- Wear disposable or washable gloves whenever handling items that may carry virus to limit spread and also when using cleaning agents to protect your hands from harsh chemicals.
- The infected person and anyone attending an infected person should wear a face mask
- Good ventilation of the room is important as it flushes out large and small airborne droplets and provides clean air. Leave windows open as much as practical
There’s also advice available from the US Centers for Disease Control and Prevention.
