As cases of the novel coronavirus continue to rise in Canada, many wonder (and are often confused) about how long the virus can last on surfaces and in the air.
In a recent report from the National Institute of Allergy and Infectious Diseases published on Tuesday, scientists tried to pinpoint exactly how long the virus could remain on a variety of surfaces, including household items and hospital settings, through coughing or touching.
To perform the experiment, researchers used an aerosol device to mimic the microscopic droplets that would be caused by a cough or a sneeze. Next, they waited to see how long the virus would remain on surfaces.
The report found when the virus was in droplet form (mimicking someone coughing or sneezing via the aerosol device) it could be transferred to others and infect people for at least three hours.
On surfaces in particular, the virus was viable after three days on plastic and stainless steel, and less than a day on cardboard.
Study offers valuable insight on the virus
Jozef Nissimov, an assistant professor at the department of biology at the University of Waterloo in Waterloo, Ont., told Global News this study gives researchers “valuable experimental data.”
“The findings add to previous reports on other coronaviruses, such as those responsible for the Severe Acute Respiratory Syndrome (SARS) the Middle Eastern Respiratory Syndrome (MERS),” he said.
He says the study further supports current advice given by the World Health Organisation (WHO), government agencies and infectious disease experts on the importance of disinfecting your hands and frequently used surfaces.
“The study, however, is not exhaustive. As the authors point out, there are a range of other factors (other than surface type) that may also impact the rate at which these viruses decay in the environment over time and more work will be needed to characterize their effect in the future.”
This could include factors like humidity, temperature, and the medium in which the virus is released (for example in phlegm or mucus), he said.
Dr. Alon Vaisman, an infection control and infectious diseases physician at Toronto’s University Health Network, told Global News while reports like these are important for the medical community, the average Canadian needs to remember that all of this is done in a lab.
“The things that people should realize is that when you use these machines to aerosolize, you are aerosolizing at a very high rate, like a very intense level … and they’re also using a very high dose of the virus.”
He said, however, this doesn’t take away from the environmental piece and it’s important for Canadians to know how long the virus can last on surfaces.
Vaisman adds when it comes to these types of studies, read the actual study and don’t delve into what you see only in headlines — this could cause fear and anxiety.
“We already know that it spreads quite readily between patients and between people,” he said. “We know that mildly symptomatic people have been responsible for the majority of the outbreak.”
He says this is why Canadians should practice social distancing.
“It’s not so much the viruses just hanging around the air and just waiting to infect ,” he said.
“Individuals who are infected are meeting commuting everywhere.”
“They’re coming in contact with lots of people.”
Wash your hands, clean your surfaces
Nissimov says any new information regarding the novel coronavirus is a good reminder for Canadians to continue following guidelines from the WHO and government agencies. This means self-isolation for an extended period of time if you’ve travelled or have symptoms, social-distancing and appropriate hand hygiene and surface sanitation.
“As a general rule, the spread of viruses relies on the availability of new hosts to infect… in other words, viruses are completely at the mercy of their hosts because they cannot self replicate,” he said.
“Viral pathogens of humans spread more easily when we are in close proximity to one another. It is this basic rule that is so important in reducing the spread of an infection and why social distancing is a powerful approach in mitigating the spread of infections like COVID-19.”
And as news about COVID-19 changes, including new research, rely on trusted sources like government officials and the WHO.
“The key take-home message is that the virus particles that cause COVID-19 can remain infectious in aerosols for hours and on different surfaces for days,” Nissimov said.
“Although the infectivity of these virus particles decreases with time, it is plausible that contact with a surface long after its contamination may result in a new infection.”
Questions about COVID-19? Here are some things you need to know:
Health officials say the risk is low for Canadians but warn this could change quickly. They caution against all international travel. Returning travellers are asked to self-isolate for 14 days in case they develop symptoms and to prevent spreading the virus to others.
Symptoms can include fever, cough and difficulty breathing — very similar to a cold or flu. Some people can develop a more severe illness. People most at risk of this include older adults and people with severe chronic medical conditions like heart, lung or kidney disease. If you develop symptoms, contact public health authorities.
To prevent the virus from spreading, experts recommend frequent handwashing and coughing into your sleeve. And if you get sick, stay at home.
For full COVID-19 coverage from Global News, click here.
–With files from Reuters
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