Why are hand washing and wearing masks important?
2020.02.01
The new coronavirus infection is spreading, especially in China.
When you hear in the news that the number of infected people and the number of deaths are
increasing every day, you may be scared. In drug stores and pharmacies, masks are out of
stock.
Washing hands and wearing a mask are a couple of the things you can do to prevent infection.
This time, I will explain why these are necessary.
How do you get “infected”?
There are three main routes of transmission of pathogens such as bacteria and viruses:
“airborne”, “droplet”, and “contact”.
“Airborne infections” are infections caused by small particles (called droplet nuclei) that cause
evaporation of the fluid of fine splashes (sprays) that scatter when you cough or sneeze, that
drift in the air and are inhaled. It is also called “spray nuclear infection”.
In the case of airborne infection, the droplet nuclei float in the air even if you are distant, so
even if you are in the same room, you may be infected.
“Splash infection” is infection caused by splashing (spraying) when coughing or sneezing.
The spray has a certain amount of weight as it contains water, so it will fall off after a certain
distance and time. So, if you keep a certain distance and wait some time, the risk of infection
will be lower.
“Contact infection” is infection by directly contacting an infected person or by touching an object
with a pathogen. For example, eating or rubbing your eyes after contact with a handrail or towel
carrying a virus can cause infection.
How to prevent contracting the new coronavirus
In the case of the new coronavirus, the possibility of airborne infection is low, and “splash
infection” and “contact infection” are considered to be the main routes of transmission.
The basis of infection prevention is to cut off the route of transmission.
In other words, droplet infection and contact infection are the main routes of transmission.
Basically, avoiding droplets containing viruses, avoiding contact with infected people, and not
touching those with the virus attached are the basics of prevention.
But you don’t know if the virus is attached.
The doorknobs used by an unspecified number of people, the straps on trains, etc., may have
viruses attached to them. And there is a possibility that the virus also attaches to your own
hands when you touch them.
That’s why it’s important to wash your hands when you return home, before eating, or before
cooking.
What is the effect of a mask?
So what about wearing a mask?
Masks are said to be highly effective in preventing the virus contained in the droplets from
spreading around due to coughing and sneezing. In other words, prevention of the spread of
infection is more important than prevention of infection.
However, in places that are crowded, droplets containing viruses may spread. Therefore,
wearing a mask also helps prevent infection in crowds.
Reference:
◎ Ministry of Health, Labor and Welfare “Q & A on New Coronavirus”
https://www.mhlw.go.jp/stf/seisakunitsuite/bunya/kenkou_iryou/dengue_fever_qa_00001.html
◎ Prime Minister’s Office “Preparing for New Coronavirus Infections-Let’s know what each
person can do-”
https://www.kantei.go.jp/jp/headline/kansensho/coronavirus.html