Erin Bromage discusses in great deal how the virus behind Covid-19 moves from person to person:
In order to get infected you need to get exposed to an infectious dose of the virus; the estimate is that you need about ~1000 SARS-CoV2 viral particles for an infection to take hold, but this still needs to be determined experimentally. That could be 1000 viral particles you receive in one breath or from one eye-rub, or 100 viral particles inhaled with each breath over 10 breaths, or 10 viral particles with 100 breaths. Each of these situations can lead to an infection.
How much Virus is released into the environment?
A Toilet flush: Without a seat to close, a single flush releases ~8000 droplets into the air. If the person using the restroom before you was infected, you have a chance of contracting the virus via breathing the air in the bathroom. While the paper in question did not look for live virus, it is clear that infected people are releasing, at a minimum, viral RNA, in bowel movements. Don’t use public bathrooms or wait a few minutes before entering so gravity can bring the droplets to the floor.
Lots more, well-written and comprehensible to those of us lacking degrees in the subject, like me.
