Infectious diseases

＞For everyone＞Infectious diseases

The relationship between infectious diseases and immunity

Although it is a little old paper, against those who have or do not have immunity to influenza, there are virus inhalation and drop to nasal passages experiments. As you can see from the figure below, the risk of infection with or without immunity is obvious from the numbers. You can also see the difference in risk between droplet infection and contact infection.
For respiratory infections such as influenza, I think that countermeasures against droplet infection should be strengthened rather than contact infection.

Droplet infection

To understand the infection countermeasures, I recommend that readers divide the droplet infection into two types, "splashed infection" and "cigarette smoke-like infection"（These two words are made by Dr. Hayato Yamauchi）.


"Splashed infection" is that virus spreads with large saliva droplets that fly far away.
On the other hand, "cigarette smoke-like infection" is, as the name suggests, that a small and light particle pervading the area like cigarette smoke.
If we wear mask correctly, we can prevent both types of the infections.

Cough etiquette

Do readers know "cough etiquette"?
Cough etiquette is very important in doing respiratory infections' countermeasures. SARS in 2003 lead CDC (Centers for Disease Control and Prevention) to add cough etiquette as a preventive measure that should be taken normally in medical institutions. The risk of respiratory infections such as influenza is higher in droplet infections than in contact infections.
So it is especially important to take countermeasures against droplet infections, and one of the most essential things is to wear a mask.
Even if we don't have a mask or handkerchief, you can take countermeasures by doing an elbow block.
Since all we have to do is simply cover their mouth with their elbows or sleeves, anyone can do it anytime, anywhere.
Also, there is no comfortable and safe mask.
It is recommended to use an elbow block together if readers are likely to cough when wearing a comfortable mask.
In addition, when taking countermeasures, it is necessary to consider the "distance" and "position" at which droplets fly.
The "cigarette smoke-like infection" that is already explained needs special consideration.
Face shields, mouth shields, vinyl curtains and so on that are often seen in everyday life can prevent "splashed infection", but cannot prevent "cigarette smoke-like infection" that leaks out like smoke.
We must take reasonable countermeasures with the correct knowledge.

Summary