This story will leave no doubt in your mind about why staying at home is the best preventive measure against the novel coronavirus. The story is based on research that determines how long does it takes for a healthy person to get a novel coronavirus infection from a Covid-19 patient.

The novel coronavirus spreads through body fluids coming out of the nose and mouth of an infected person. Acts of breathing, speaking, coughing and sneezing release loads of virus particles into the air. Besides, humans have the habit of spitting and blowing their noses.

But how long should you be exposed to an infected person to get enough novel coronavirus particles to turn yourself into a Covid-19 patient?

Comparative immunologist Erin Bromage of University of Massachusetts Dartmouth conducted a study to theorise a formula of coronavirus infection: "Successful Infection = Exposure to Virus x Time".

He has calculated time of exposure for a successful infection in the cases of simple breathing and normal conversation wherein one healthy person shares air space with an infected person.

In a single breath, a person releases 50-50,000 droplets and aerosols. We don't usually realise that breathing releases so much of fluid in air. Those wearing specs must have noticed vapour condensing on their eye glasses while wearing a mask -- that's the released fluid at work.

Under normal weather conditions, most of these droplets quickly fall to the ground under the force of gravity. Some remain suspended for some time. There is no study on how many novel coronavirus particles come out with every breath an infected person exhales but this study on influenza virus puts the number at 20-33 per minute.

출처: INDIA TODAY