Your housemate or partner has a fever and a cough – the classic Covid-19 symptoms – so is it inevitable you’ll become infected, too? The chances are high, but it’s not a foregone conclusion.
Due to ventilation, Covid-19 transmission is more likely to occur indoors than outdoors, says Oksana Pyzik, an infectious diseases expert and senior teaching fellow at UCL.
We also know the risk of infection increases with prolonged contact, meaning you’re more likely to catch Covid-19 from someone you spend a lot of time around (such as a housemate) than you are from passing someone with Covid-19 in the supermarket.
While the risk of becoming infected if you live with someone is considered high, not everyone who comes into contact with Covid-19 will become infected.
“A study conducted in New York demonstrated that approximately 38% of household contacts tested positive for SARS-Cov-2 [the virus that causes Covid-19], which is comparable to the secondary infection rates reported in China,” Pyzik says.
“Although the public view household visits as a low-risk activity, a significant number of super spreader events are linked to contact within households when widespread community control measures are in place.”
More then 3,000 UK students have faced university lockdowns due to virus outbreaks, but your risk of catching Covid on campus will depend on your housing set-up – and your housemates.
“Students who have part-time jobs as essential or key workers place higher risk on household contacts as they are more frequently exposed to infectious individuals than the general population,” says Pyzik.
The risk of transmission decreases in halls of residence and off-campus housing when shared spaces such as kitchens and common areas are closed, adds Pyzik, although this isn’t always possible.
“The lessons learned from US universities is that viral transmission between asymptomatic students on campus occurs more quickly than we can stop it without resorting to locking down students,” she adds.
Because of this, Pyzik, believes we need screening of asymptomatic students, plus a “blended” curriculum featuring online learning and small, socially distanced classes, to reduce the risk of transmission between housemates.
In a family home, there are also things you can do to reduce your risk of transmission from the 38% average.
Opening windows and trying to stay at least one metre apart from family members or housemates is a good place to start, especially if you can’t avoid mixing with others outside the home.
Closing the toilet seat before flushing may also reduced the “cloud of virus-containing aerosol droplets” from circulating around your bathroom.
It’s also important to maintain good hand and surface hygiene – even before anyone in the household has started to show symptoms.
“If any one in the group is infected, a) they will be expelling droplets which will settle on to surfaces and b) they will likely be touching their mouth or nose and have the virus on their hands,” Professor Sally Bloomfield from the London School of Hygiene and Tropical Medicine previously told HuffPost UK. “Avoiding transmission via their hands and contact surfaces is key.”
Ultimately, try to avoid coming into contact with the infected person – and avoid sharing kitchen and bathroom essentials like hand towels, tea towels, plates, bowls, cups and cutlery.
Other experts have even recommended wearing face masks in the home to protect loved ones if you’ve picked up the virus – but we can’t imagine many will take up that advice 24/7.