One of the reasons that the Covid-19 pandemic was worried is that it is difficult to know how the virus affects individuals. Most people are infected with the coronavirus,81%According to the United States Centers for Disease Control and Prevention (CDC), some people have little or no symptoms, rely on mechanical ventilation or breath at all.
But as researchers continued to study the disease, they began to understand which populations tended to be the hardest hit. The following factors, at least as researchers now understand, increase the likelihood of severe symptoms from Covid-19:
age
Chinese researchers First decide People over the age of 60 are at highest risk for severe symptoms of Covid-19. Different studies have slightly different definitions of severe or severe symptoms, but often include dyspnea (based on respiratory frequency, blood oxygen levels, duration of symptoms), fever, and confusion. Basically, symptoms are severe if they seem to require immediate medical attention.
In the U.S., 31-59% of adults 75-84 years diagnosed with the virus show symptoms severe enough to be hospitalized, compared with 14-21% of confirmed patients aged 20-44 Is aAccording to the CDC.
This is how the CDC is Additional precautionary measures To prevent getting sick—and why grocery stores are increasingly specifying time Elderly Shopping.
Other medical conditions
Older people are also more likely to have underlying health conditions that can make Covid-19 symptoms more severe. But they are not the only ones. Everyone, regardless of age, may have a condition that is at higher risk.
People with heart disease, diabetes, cancer, etc. More likely to cause severe symptoms Covid-19, it can lead to High risk of deathThan people without underlying illness. People with underlying diseases are more likely to be hospitalized for the virus.
Some diseases can impair the function of organs like heartSome alter the way the immune system works, which can hinder the body’s response to coronavirus. Smoking and vaping, as well as chronic lung disease, increase lung damage, May make Covid-19 symptoms are more severe, but few studies have examined it.
gene
Several teams of international researchers are working to understand how genetics can affect the severity of Covid-19 infection. They are looking for different places, but they know a lot about where to start.
SARS-CoV-2, the coronavirus that causes Covid-19, Attach yourself A specific receptor outside the cell called ACE2 that is used to invade the cell. It’s like a cellphone phishing scam like me Colleague Katherine Foley writes. Slight variations in the genetic blueprint of their receptors may play a role in the degree to which a person becomes ill.
“There are huge differences between clinical outcomes and countries, and how much is explained by genetic susceptibility is a very open question,” said geneticist Andrea Gannah of the Finnish Medical Institute at the University of Helsinki. Told science magazine.
Other teams are looking at whether blood types determined by genes can alter the severity of Covid-19 symptoms in patients. Ah Preliminary research In a study conducted in Shenzhen and Wuhan, China, patients with blood group A showed more severe symptoms than those with blood group O. The study authors caution that it is too early to make clinical decisions based on this finding.
sex
Chinese researchers 58% of patients A man was hospitalized at Covid-19. There was a similar imbalance in the patient We And ItalyAlso.
A few Infer This is a social habit of men (and Many do not wash their hands Often) they are more likely to get sick. This means that the increase in hospitalization is simply the result of an increase in the number of overall infections. But men are generally Weak immune system Tend to More fundamental health issues Than women; two X chromosomes in women Protection quality For many conditions.
Previous vaccinations
Recently, Researcher observed something (Pdf) Somewhat surprising: Countries where vaccination with Calmette-Guerin (BCG) vaccine is required Oldest There were fewer cases and deaths from Covid-19 to fight tuberculosis. Countries affected most by this disease, such as Italy, the Netherlands, and the United States, do not have universal vaccination programs. Others, like Iran, have too new programs to reach older people.
This is not the first time that researchers have found that the BCG vaccine works to fight diseases other than tuberculosis. Used for treatment Early bladder cancer And Prevent leprosy. And in one study, perhaps the most relevant to Covid-19, vaccines were also Reduce severity Of lower lung infections caused by the virus.
Currently, researchers in countries such as Australia and the Netherlands Start a trial Find out if the BCG vaccine can prevent and reduce the severity of Covid-19.
