How do you catch an infectious disease? Types of infection routes
The weather is getting cooler and cooler. The simultaneous epidemic of influenza and the new
coronavirus, also known as a “twin-demic”, is drawing attention as winter begins in earnest..
In anticipation of the possibility of a simultaneous epidemic (twin-demic), the national
government has distributed new corona test kits and masks to prevent infection to medical
institutions, so that patients can be tested at familiar clinics such as family doctors. It looks like
we’re preparing for it, but on the other hand, it’s important for each of us to take preventive
measures against infectious diseases.
By the way, there are several transmission routes for infectious diseases. In other words, “how it
spreads” changes depending on the type of infectious disease.
In order to prevent catching and spreading an infectious disease, it’s essential to know how the
disease is transmitted – the “infection route”. Know the main transmission routes and overcome
the twin-demic wisely.
Four main transmission routes
There are four main transmission routes for infectious diseases: (1) airborne infection, (2)
droplet infection, (3) contact infection, and (4) oral infection.
① What is “airborne infection”?
The pathogen contained in the droplets that are released from the infected person’s mouth
spreads along the air stream while maintaining infectivity, and is transmitted by another person
Known pathogens that infect the air are tubercle bacilli, measles virus, and varicella-zoster
② What is “droplet infection”?
Infection by a nearby person inhaling a pathogen contained in a splash (spray) scattered by
coughing, sneezing, or conversation. Since the droplets contain water and are heavy, the reach
is said to be about 1 to 2 meters.
Known pathogens that infect droplets include influenza virus, rubella virus, and adenovirus (cold
③ What is “contact infection”?
Infection is caused by touching one’s nose or mouth with a hand that has touched the skin or
mucous membrane of an infected person, or touches a doorknob or handrail with a pathogen.
Known pathogens that are contact-transmitted are norovirus, influenza, varicella-zoster virus,
and Staphylococcus aureus.
④ What is “oral infection”?
Infection by consuming water or food contaminated with pathogens.
Known pathogens that infect orally include norovirus, O157 (enterohemorrhagic Escherichia
coli), and Salmonella.
What is the difference in infection route between influenza and the new corona?
The main transmission routes for influenza are “droplet infection” and “contact infection”.
On the other hand, the infection route of the new coronavirus has likewise been said to be
droplet infection and contact infection; however, recently, there is a growing belief among
experts that in a room with poor ventilation, there will also be “airborne infection “.
What are “social distance” and “Three C’s” for?
It is often said that we should keep social distance in the prevention of new coronavirus
infections. Keep a distance of about 2 meters from other people in situations such as lining up
for shopping at a supermarket, eating at a restaurant, or waiting in the waiting room of a
This social distance is a precautionary measure based on droplet infection.
Droplets fly within a range of 1 to 2 meters, so let’s separate a little farther.
Another thing that is often said is to avoid the “Three C’s”.
The three densities are closed, crowded, and close-contact. Don’t let a large number of people
get together and talk in a closed space. This would be an airborne infection-aware precaution.
Preventive measures that are mindful of the infection route
Influenza is a droplet infection and a contact infection, and the new corona is a concern as an
airborne infection as well.
To prevent droplet infection, it’s important to keep social distance, use cough etiquette, and
wear a mask to prevent it from being transmitted to others.
Hand washing and disinfection habits are important in preventing contact infections.
And what’s important in preventing airborne infections is the avoidance of the Three C’s and,
above all, having good ventilation.
Do what each and every one of you can do so that you don’t have a hard time and don’t pass
the virus on to others!