The elderly or who already suffer from diseases such as diabetes, asthma or hypertension are the most vulnerable to the new coronavirus epidemic, which has also caused more deaths among men.
Since its appearance in China in December, this respiratory infection infected more than 85,000 people in more than 50 countries, of which 2,800 died.RELATED
In most cases, it causes banal and moderate symptoms such as cough, fever and tiredness, but in the most serious patients may have acute respiratory problems, suffer severe renal insufficiencies and record failures in several organs, which can lead to death.
The average mortality rate remains small, between 1 and 3%, a percentage higher than seasonal flu (0.1%), but lower than the previous epidemics linked to a coronavirus that were much more virulent: 34, 5% in the case of MERS (Middle East Respiratory Syndrome) or 9.6% in the case of SARS (Severe Acute Respiratory Syndrome), whose virus is 80% similar to the new coronavirus.
Some segments of the population are at greater risk, according to available data.
The most complete analysis so far, published on February 17 by the Chinese authorities and later on the 24th, by the American medical journal Jama, also shows that the mortality rate increases with age.
So far there have been no deceased under 10 years. Up to 39 years, the mortality rate is very low, 0.2% and goes to 0.4% in people over 40. It reaches 1.3% in patients between 50 and 69 years and is of 8% in those over 70.
In the case of those infected with more than 80 years, the rate goes up to 14.8%.
Outside of China, there are also many elderly people among the victims. In Italy, the most affected country in Europe, at least six people in the first 14 deaths were around 80 years old.
The children, preserved
The absence of victims among the youngest leaves the experts perplexed because babies and children tend to be more vulnerable to this type of infectious diseases.
“It is surprising because when we look at all other respiratory, bacterial or viral infections, we always have many serious cases among the elderly and also among the youngest, especially in those under five,” said Cécile Viboud, an epidemiologist in the National Institute of Health of the United States.
“You have to see if there is no increased form of protection from the recent seasonal coronavirus epidemic,” which causes colds, says John M. Nicholls, a pathology professor at the University of Hong Kong.
A second hypothesis is that the children’s immune system is designed to “not overreact to new infectious agents.”
Another important feature of COVID-19 (the name of the disease caused by the virus) is that men die more than women. 63.8% of the fatalities so far are male.
The aggravating factor of tobacco
According to Viboud, the fact that there are more men dying due to the coronavirus could be explained “at least in part” by the fact that men, in general, smoke more than women and tobacco increases the risk of death.
But they also have to see differences in behavior or immune response.
Other risk factors, according to Chinese studies, would be the fact of suffering a chronic disease. Thus, mortality is 6.3% among patients suffering from respiratory diseases, 10.5% among those with cardiovascular disease and 7.3% among diabetics.
People with cancer and hypertension are also more affected.
Outside of China, these parameters are repeated. For example, among Italy’s first 14 fatalities, one was in cancer treatment, another had suffered a heart attack days before, another had heart disease, and two were already ill with a severe prognosis before contracting the virus.
Another significant fact is that the Chinese health professionals who died were all quite young.
According to David N. Fisman, an epidemiologist at the University of Toronto, they were undoubtedly more in touch with the sick than older doctors or nurses.
They could also sin of “inexperience” when they took care of contagious patients and did not properly use protective equipment at a time when Chinese hospitals were overwhelmed. (I)