LONDON – Doctors noticed the change last month as a new variant of the coronavirus spread in the UK. More young men and women with serious cases of Covid-19, a disease that previously caused the worst symptoms, mostly in older patients and men, have been seen in hospital’s critical care units.
The change – now backed by statistical studies – is part of an urgent puzzle that preoccupies British public health officials as they race to figure out a strain of the virus that is more transmissible and, some studies suggest, could be more deadly than earlier versions.
Scientists say that one of the early hypotheses is that one of the genetic mutations of the virus makes a better attack on a larger number of cells in the body, which leads to serious diseases in people who would have only mild symptoms or no symptoms with previous versions of Covid-19.
David Strain, a physician and instructor at Eketer University School of Medicine who also treats patients with Covid-19, said the initial study paints a picture of a variant of the virus that is like a burglar who got better and broke in and entered – in vulnerable cells. in this case not the house.
“We think that’s why it makes people sicker and more transmissible at the same time,” said Dr. Strain.
Virologists suspect that it is a certain mutation known as N501I on the spike protein of a new variant that has improved its ability to enter and infect human cells and move more efficiently through the human body.
Some doctors, such as others. Straina, they think it is behind the rise of younger men and women – who in most cases of the pandemic fell ill at lower rates – who ended up in hospital.
Some things, as doctors and scientists say, do not seem to have changed with the new variant. Once hospitalized, patients appear to have the same chances of survival as before, and physicians cannot determine which variant the patient has by symptoms.
In London, the south-east and east of England, where the new variant was first identified in a test sample from 20 September, the mean age of patients admitted to intensive care units fell from 61.4 years between September and the end of November to 58.9 years from 1 .December to January 21st.
The share of women admitted to the ICU increased from 30.1% to 35.1% in the same period. Data from the rest of the country show a similar pattern.
During December, the share of children aged 18 to 54 admitted to English hospitals with Covid-19 also began to grow, before the national lock was introduced on January 4.
Not all doctors are convinced that this is explained by mutations in the new variant. Some think it could also be a matter of behavior change, with more people, especially younger ones, interfering during the holidays and becoming infected.
Luka Allen, a local doctor in Oxford, for example, said that he treated more younger patients, but that he received more patients with Covid-19 in general, and it seems that the attitude of people is the same as in the first peak.
He attributes the increased numbers to the greater portability of the new variant and increased socializing during the holidays. “It increases the chances of their contact with us,” said Dr. Allen.
There is still a great deal of debate about whether the new variant is actually more deadly, as some research shows.
It is estimated that the new variant, which has become the dominant version in Great Britain, is 30% to 70% more contagious than the earlier varieties. Last week, the government’s advisory board said that studies suggest that there is a real possibility that it could be 30 to 40% more deadly than the previous variant.
The advisers say their conclusions are indicative. “Although there is uncertainty, we cannot always wait for safety,” said Peter Horby, chairman of the board, the Advisory Group on New and New Respiratory Threats of the Virus or Nervtag.
Julian Tang, a clinical virologist and professor of respiratory medicine at the University of Leicester, said more evidence was needed to prove the new variant was more deadly, given that social interference was allowed during the winter months, significantly accelerating hospitalization rates. .
“Viruses mostly mutate to be more transmissible and less deadly,” he said.
The spread of the new variant coincided with a huge increase in the number of hospitalized people with Covid-19 and an increase in the number of people who died from the disease in Great Britain, putting the public health service under unprecedented pressure. Covid-19-related deaths in the UK have been close to 100,000 since the start of the pandemic.
The disease caused by the previous variant does not seem much different from the one provoked by its ancestors, but since the virus itself is able to move more easily through the patient’s system, it can surpass the body’s immune response, doctors suspect.
“If you become much stronger in a relationship, you may need a lower infectious dose to become infected, which would increase the risk of transmission,” said Dr. Horbi. “Then, if it manages to spread between cells much faster inside the lungs, it can increase the rate of disease and the rate of inflammation, which can then progress faster than your body can react.”
To determine if the new variant was more deadly, the researchers looked at data from about 850,000 cases of coronavirus tested in the community, where they knew which variant of the virus each person had, including between 1,400 and 1,900 deaths.
“You have to compare people who are as similar as possible to each other,” said John Edmunds, author of one of the studies at the London School of Hygiene and Tropical Medicine.
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The researchers matched groups of people based on age, gender, and ethnicity, as well as income and where they live, to reduce the effect that pressure on hospitals could have on mortality rates.
Dr. Edmunds’ group found that if two similar people had coronavirus, the one who had the new variant had about a 30% higher chance of dying from the disease it caused. A group from Imperial College London found a similar probability of mortality in the new variant compared to its ancestor. Researchers at the University of Eketer found an increase in the risk of mortality by 91% from the new variant, although that could be because the population it examined distorts older years, said Dr. Strain.
Another English public health study put the chances of dying after infection with a new variant about 65% higher than the old version.
The results are preliminary and because only about 10% of all cases in the UK have a known variant of the virus, it may not represent a representation of the entire population.
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