How infection starts
Our nose and mouth are gateways for getting an infection and transmitting an infection. Infectious pathogens from an infected person’s nose and mouth can spread easily and infect us in the form of aerosols and droplets through sneezing, talking, breathing, contaminating contact surfaces, etc. Likewise, when we are infected, we could transmit infectious pathogens to people around us via the same route.
An infection begins when the infectious pathogens enter your upper respiratory tract – nose ① and mouth ② and start to colonize the nasopharynx Ⓝ (back of your nose) and oropharynx Ⓞ (back of your throat).
The infection continues to spread into the trachea Ⓣ and esophagus Ⓔ, infecting your lungs and deeper organs and causing severe illnesses.
Worse, these infectious pathogens that enter your upper respiratory tract can also kill and alter the cells lining it. This allows another bacteria, virus or fungi to invade and cause a co-infection and/or secondary infection. This exacerbates the condition, often leading to severe illnesses, complications and hospitalization.