[BostonCard]

I'm a bit weary of the reports of the virus being able to live for 3 hours in the air or that it survives for several days on cardboard, etc.  We have incredibly sensitive instruments to pick up very small amounts of stuff.  The real question is how much is required to cause infection and is there enough of it in an enclosed room an hour after an infectious patient was in it to infect an uninfected person.  I don't think we have enough evidence to say one way or another, and it is probably a gradient.  Your probability of infection is going to be proportional to how many viral particles you come in contact with, which will be inversely proportional to how much time has passed from when an infected person was somewhere along with a host of other factors like the size of the room, environmental conditions, ventilation, and the degree of viral shedding of the infected person.

I wish we knew the answers to those questions so that we can provide people practical advice as to what is "safe" and what is not.  In the absence of such recommendations, it pays to take reasonable precautions and avoiding unnecessary risk.

BC

The spread of this virus seems to justify drawing hard to believe conclusions. It's not just spreading from people not washing their hands and touching their face.

There is nothing about the spread of the virus that is unusual; it is roughly what one would have expected for a virus with this basic reproduction number and incubation period unleashed in a world without any prevalent immunity.

BC

[BostonCard]

I'm a bit weary of the reports of the virus being able to live for 3 hours in the air or that it survives for several days on cardboard, etc.  We have incredibly sensitive instruments to pick up very small amounts of stuff.  The real question is how much is required to cause infection and is there enough of it in an enclosed room an hour after an infectious patient was in it to infect an uninfected person.  I don't think we have enough evidence to say one way or another, and it is probably a gradient.  Your probability of infection is going to be proportional to how many viral particles you come in contact with, which will be inversely proportional to how much time has passed from when an infected person was somewhere along with a host of other factors like the size of the room, environmental conditions, ventilation, and the degree of viral shedding of the infected person.

I wish we knew the answers to those questions so that we can provide people practical advice as to what is "safe" and what is not.  In the absence of such recommendations, it pays to take reasonable precautions and avoiding unnecessary risk.

BC

The spread of this virus seems to justify drawing hard to believe conclusions. It's not just spreading from people not washing their hands and touching their face.

There is nothing about the spread of the virus that is unusual; it is roughly what one would have expected for a virus with this basic reproduction number and incubation period unleashed in a world without any prevalent immunity.

BC