TALLINN – Estonian virology professor Irja Lutsar told public broadcaster ERR that, compared to the previous week, the number of mild coronavirus cases has increased in the world and currently makes up 92 percent.
According to Lutsar, the reason for this is probably the widespread testing implemented in many countries as well as more frequent detection of mild cases of illness.
"In Italy, which is equal to Hubei province in terms of population, there were 21,157 infected people as of March 14 -- at that, there were altogether 69,000 infected people in Hubei province over the course of approximately two months -- and during the period of increase, the average number of cases rose by approximately 20 percent compared with the previous day. The daily maximum of Hubei was approximately 4,000 cases, in Italy, the number was nearly 3,500 yesterday [Saturday]," Lutsar told ERR. "What is the difference between South Korea and Italy? Foremost the age of those who are ill. While in South Korea, 45.2 percent of infected people are below the age of 50, the indicator is only 21.4 percent in Italy. At the same time, those older than 80 make up 18.4 percent of infected people in Italy and 3.1 percent in South Korea. While in South Korea, the biggest group of infected people is 20-29-year-olds, 28.9 percent, then only 3.9 percent of those infected in Italy fall within that age group," she said.
According to Lutsar, the infection rate among children is still very low in all countries -- 0.5 percent of all those infected in Italy and 1 percent of all those infected in South Korea. According to information available for South Korea, the share of women and men among those infected is 62 percent versus 38 percent.
"With the exception of children -- and even this is not clear -- the frequency of infection seems to be the same for all age groups, with the difference being that for younger people, the illness is mild, and for older people, severe or very severe. Thus, countries with a low proportion of those under the age of 50 are likely to have a high number of undiagnosed infected people with mild symptoms in these age groups," Lutsar said.
According to the professor, countries that are able to keep the disease away from the older population, either through intensive testing and isolation of infected people, such as South Korea, or very good contact monitoring, such as Singapore, are more successful in preventing deaths. There are no reported cases of the infection among people over the age of 80 in Singapore.
"Worldwide, mortality is estimated at 3.4-3.7 percent, which varies greatly from country to country and appears to depend primarily on the age structure of the patients -- 0.6 percent in South Korea, with only 3.2 percent of those infected over the age of 80, versus 6.8 percent in Italy, with 21.4 percent of those infected over 80 years of age," Lutsar said. "It is believed that, in general, mortality rates are around 1 percent, and in countries where it is higher, the medical system is not worse, but many patients with milder symptoms are undiagnosed."
According to Lutsar, of European countries, there is a mortality rate of only 0.2 percent in Germany. In the Nordic countries, too, there have been only a few deaths so far.
"All available data indicate that male mortality is about twice as high as female mortality," Lutsar said. "In South Korea, the mortality rate is 1.27 percent for men and 0.57 percent for women, and in China, the mortality rate is 4.7 percent for men and 2.8 percent for women," she added.
Mortality increases significantly with age. For example, in Italy, there have been one or two deaths among infected persons below the age of 50, the mortality rate is 0.2 percent among people between the ages of 50 and 59, 2.5 percent among people between 60 and 69, 6.4 percent among people between 70 and 79 and 13.2 percent among people older than 80. There is similar data also in China and South Korea.
"The next four weeks, if not six, will be very difficult. The real damage done to the economy will be determined once the pandemic is over. However, this will take time," Lutsar said.