A new study from the University of Oxford has found that the time you spend in contact with someone infected with coronavirus is just as important as your distance from that person.
How likely is it that you will get it? COVID-19 (new coronavirus infection) After coming into contact with an infected person? This is a question on many people's minds during the pandemic, and a group of British researchers has finally found the answer.
Researchers from the University of Oxford's Nuffield School of Medicine analyzed data from 7 million people in England and Wales who were notified by the national NHS Covid-19 app that they had been in contact with an infected person during the health emergency. did. .
The goal was to find out how many of those alerted actually became infected with the SARS-CoV-2 virus.
The NHS coronavirus app was shut down in April 2023, but people who downloaded it were able to let others know they were infected.
At the same time, the app will send a warning to the user (based on non-mandatory reporting to the app) if the user comes near an infected person. In that case, people will need to self-isolate or get tested.
The job of Luca Ferretti, principal investigator of the Oxford University study published this month in Nature, and his colleagues was to understand whether the app worked correctly.
Have you notified people if there is a substantial risk? The short answer is yes. But researchers discovered more than that.
“The app collects anonymous information about who has been notified of risk, who has been tested, who has received a positive result, and information about specific contacts (duration, distance, etc.) ,” Ferretti said. Euronews Next.
“When we looked at what the app calculated as a risk to an individual in terms of distance and duration, we found that the two were very closely correlated,” he says.
duration and distance
The researchers used this “treasure trove'' of information to study the relationship between distance and exposure time to an infected person, and how this affected the risk of infection.
And it turns out that duration is just as important, if not more important, than distance.
“Everyone was focused on distance. There were rules of one or two meters in shops and stations. But distance shouldn't have been the focus, because as we now know… Because the truth is more nuanced than that,'' Ferretti said.
“Once you're a short distance away from someone, that time becomes critical. If you're exposed for 10 seconds, you must be very unlucky for particles from an infected person's mouth to reach your mouth or nose. But there If you spend an hour in , you will naturally try your luck 60 times in that one minute.
The researchers found that longer exposures at greater distances had similar risks as shorter exposures at closer distances.
There is no golden rule for how much time you can spend with an infected person before you yourself become infected with COVID-19. This is because it may change depending on the behavior of the infected person. For example, if they cough frequently, others are more likely to become infected.
But the longer you spend with someone who is sick, the more likely they are to get sick themselves, even if you keep two meters apart at all times.
“In fact, what we're seeing is that many of the people who are getting sick are people who were considered family members because they had been together for more than eight hours,” Ferretti said. said.
“And those were around 6 percent of contacts and 40 percent of transmissions.”
advertisementWhat can we learn from this?
For Ferretti, the takeaway from this study is that time will matter when fighting the next pandemic or epidemic.
“Of course, distance is still important,” he says, “but once that's established, you need to talk about duration.”
Ferretti said the time of contact with an infected person “honestly hasn't been taken into account very much in the response to the pandemic, and it should have been taken into consideration.”
In the era of big data, researchers say it should be possible to harness modern technology to develop epidemiological tools to help fight the spread of new pathogens.
But researchers are concerned that not enough is being done to harness the knowledge gained during the pandemic to help fight the next one.
advertisement“I don't blame people who want to forget about the coronavirus,” he said. “What concerns me more is the fact that policymakers are choosing to forget about it at an institutional level, because it will dilute all the knowledge and skills that we have acquired. Because we’re going to get to that point.”
