"Don't underestimate" Infectious disease experts warn Omicron strains

2022.1.12 13:00
It seems that the new variant of the novel coronavirus "Omicron strain" has spread at an accelerating rate and has entered the sixth wave of the spread of infection. The aggravation rate of the Omicron strain is said to be lower than that of the Delta variant, but if the number of infected people continues to increase, medical tightness may occur. Infectious disease experts warn, "Don't underestimate."

◆ Infectivity is 2 to 4 times more likely than Delta variant

Omicron strain of novel coronavirus (National Institute of Infectious Diseases)

The Delta variant, which raged in the fifth wave last summer, is rapidly being replaced by the Omicron strain. According to the Tokyo Metropolitan Government, it is estimated that about 70% of infected people were Omicron strains in the week leading up to January 6.
In the case of the Delta variant, it took two and a half months from the first confirmation of infection to reaching 70%, but in the case of the Omicron strain, it reached in less than a month. Its infectivity is two to four times higher than that of the Delta variant.

◆ There is a high possibility that the number of hospitalized people will increase even if it is mild.

On the other hand, there are hopeful observations regarding the severity rate. Shigeru Omi, chairman of a government subcommittee on the nation's COVID-19 response, paid attention to the situation in Okinawa Prefecture, which currently has the largest amount of data on domestic Omicron stocks.According to the statistics submitted to the advisory board, an expert organization that advises the Ministry of Health, Labor and Welfare, 92.3% of the 675 people who have been infected with the Omicron strain in Okinawa and are undergoing medical treatment are asymptomatic or mild. No one was so severely ill that he or she required tracheal intubation.
Nevertheless, the advisory board chairman, Takaji Wakita, director of the National Institute of Infectious Diseases, said with caution, "It is suggested that it may be less likely to become severe compared to the Delta variant." The reason is the age structure of people undergoing medical treatment infected in Okinawa. 60% of the total were young people in their twenties or younger who had a low risk of becoming severely ill.
In a survey of 50 infected people in Okinawa, only 4% had complete asymptomatic, 72% had fever, and 6% had dyspnea. The number of hospitalizations is likely to increase, even if it is mild. Furthermore, if the infection spreads to the elderly and unvaccinated people who are liable to become severely ill, it will not be easy to secure a bed.

◆ New infection in one day, possibility of 50,000 people

"If you underestimate the Omicron strain as if it were just a cold, and don't restrict the behavior of infected people to let economic activities go on like UK, corona control will fail." Yoshihito Niki, Visiting Professor of Showa University (Clinical Infectious Diseases) warns. At the peak of the fifth wave of Delta variant, there were about 26,000 new cases per day nationwide. Dr. Niki said, "There is a possibility that 50,000 people will go this time." "Even if the hospitalization rate is half that of the Delta variant, if the infectivity is doubled, medical care will be tight and the number of people receiving medical treatment at home will increase, deaths will occur mainly in the elderly. "
Nobuhiko Okabe, head of the Kawasaki City Institute for Public Health, who is also a member of a government subcommittee and the advisory board, said, "The low severity rate of Omicron strains is good and reassuring." However, he said, "If young people have symptoms, and they are absent from school or company, hospitals and infrastructure will not function and social problems will occur. Even if individual symptoms are mild, infection must be suppressed as a group."

This article is composed using Google Translate customized exclusively for The Chunichi Shimbun. The translation may have limited accuracy.


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