Corona Virus Why Increased Infection in Hokkaido? The relationship between temperature and humidity?

Corona Virus Why Increased Infection in Hokkaido? Relationship between temperature and humidity or November 6, 8:00 p.m.

In Hokkaido, the number of new infections of the new coronavirus exceeds 100 for two days in a long time, and the infection is spreading more rapidly than in other regions.
On the other hand, there are concerns about the spread of infection in Tokyo, such as more than 200 people confirmed infection for two consecutive days.
In the start of a full-scale winter, experts are calling for thorough measures against infection, such as frequent ventilation, as there is a possibility that the infection will spread in the same way throughout the country in the future.

Rapid increase in infection in a short period of time

In Hokkaido, the number of infected people confirmed on a day since May 25, when the declaration of emergency was lifted, had been around 20 to 30 until the beginning of last month, but on the 23rd of last month, 51 people were confirmed infected, more than in April, when the emergency declaration was issued.

On the second day of the month, almost doubled to 96, exceeding 100 for the first time on the 5th.

Meanwhile, on June 6 in Tokyo, 242 new people were confirmed to be infected with the new coronavirus. It is the second day in a row that more than 200 people have been confirmed infected in a day.

The epidemic of infectious diseases, the relationship between temperature and humidity?

Respiratory infections such as influenza are known to be prevalent in winter, but it has been pointed out that the new coronavirus may become more prevalent in winter when temperatures and humidity are low.

As for the relationship between the new coronavirus and temperature and humidity, research has been reported so far, for example, a group such as the University of Maryland in the United States analyzed the relationship between temperature, humidity, and the outbreak of the new coronavirus in 50 cities around the world until early March, and found that the average number of infected people was relatively high at 5 to 11 degrees Celsius. It is said that it was concentrated in the area where humidity is low.

On the other hand, a group of Brazilian universities gathered and analyzed 17 studies of the new coronavirus and temperature and humidity released by each country, and concluded that cold and dry conditions were thought to be a factor in the spread of the virus, but that alone did not explain the spread of the infection.

Shigeru Nami, chairman of the government’s subcommittee on the new coronavirus, points out that the occurrence of clusters in Hokkaido and other areas has been affected by lower temperatures, more opportunities to spend time indoors, more and more people staying in “three-dense” environments and making ventilation difficult.

Hokkaido has tended to spread the infection ahead of other regions throughout the country, such as the issue of its own emergency declaration in late February.

Expert “Hokkaido is now a good place to go”

As for the rapid spread of infection in Hokkaido, Professor Ihiro Shibata of Toho University, who is the president of the Infectious Diseases Society of Japan, said, “For the first time in five days, more than 100 people have been infected, but the number of infected people currently revealed is thought to be those infected about a week ago, and there is a possibility that the number will increase further in the next week or so. If we don’t deal with it properly, the infection will spread further in the future, and there is a possibility that medical collapse will become a reality, so Hokkaido is considered to be a time of positive reintegrity.”

As for the cause of the surge, he said, “There are several possible reasons, such as getting colder and more indoors, spending more time in a ‘three dense’ environment, and being used to the continuing infection and being relaxed. In addition, influenza and regular cold coronaviruses are prevalent when temperatures are low, but there are studies that say the same is true for the new coronavirus, and it is necessary to be aware of measures again in the sense that the infection is likely to spread in winter.”

On top of that, Professor Shibata said, “Outside Hokkaido, even in areas where the infection situation is calm now, we must think about the possibility that the infection will spread as it gets colder. It is also important to avoid “three tight” again, to thoroughly wash hands and wear masks, and to ventilate every certain amount of time. However, in cold areas, frequent ventilation can actually be difficult, so I want people to be flexible in combining various measures.”

Ventilation in winter How not to lower the room temperature

How can we ventilate without lowering room temperature as much as possible in the cold?

I asked Prof. No. Rin, a professor at Hokkaido University, who has developed a proposal on ventilation methods at an institution of the Ministry of Health, Labour and Welfare.

“Utilizing corridors, etc. for two-step ventilation”

When ventilating, if cold air flows directly into the living space, such as a school classroom or a bedroom at home, you will feel the cold more.
First of all, it is possible to relieve the cold by taking the “two-step method” in which the outside air is warmed by the temperature of the entire building by taking in the outside air in the hallway or the room which is not used, and then opening the window and the door of the room and replacing it with the air of the living space.

“Open the window a little and ventilate at all times”

In cold winters and snowy conditions, if the window is fully opened and ventilated twice an hour, the room temperature will drop sharply.

It is possible to ventilate while maintaining room temperature by opening the window a little while turning on the heating and keeping it ventilated at all times.

In addition, in buildings with a 24-hour automatic ventilation system, it is effective because it is possible to change the air in the building without opening the window.