On Wed, 9 Sep 2020 22:52:08 +0100, Martin Brown
wrote:

snip

I would have though one exhaled breath with the right aerosol of virus
is enough.

Is the (actual) right answer. ;-)

You can be very unlucky and catch it from a single virus, but the innate
immune system in most people is quite good at seeing off small amounts.
Otherwise we would be succumbing to all sorts of random stuff.

Yup.

(like people who are immunosuppressed do)

That must be frightening.

It is a numbers game and the lower infection threshold for Covid19 is
still not known (for ethical reasons) but is thought to be in the
hundreds or low thousands of viruses before you reach a 50:50 outcome.

Ok.


Obviously the longer the contact time the greater the
likelyhood of the right conditions for transfer.

And the greater the viral load and risk of a stronger infection.

Although you are much more likely to catch it from entering your car
number plate in on the fiddly impossible to clean keyboard and then
rubbing your eyes. Astonishing how often people do this!

Yup, see it myself. I carry a small antiseptic spray in my pocket all
the time and when out dog walking and have to touch a gate or dog poo
bin lid / flap, pedestrian crossing button or keypad we could have a
quick spray 'in case' we touch or faces before getting home and
washing our hands properly.

That is the common bottleneck in most NHS (and other) busy carparks.

I helped an old boy pre lockdown who was struggling at a hospital
carpark. All he wanted to do was visit his daughter who had been
rushed into hospital and he was already frustrated / upset.

Same problem with supermarket and bank machine PIN entry keyboards.
(they were never designed for easy cleaning)

And stuff is no longer made of brass. ;-(

Cheers, T i m