[Lewis Thomson (OP)]

James has a bunch of questions he'd like your help for in answering.

"Is there like a ‘perfect storm’ situation that would have to happen for somebody to catch the virus through touching a surface and if so what is it?

 If I was to touch a door handle or money or anything else that might have traces of the virus on it then if I was to touch another item say for example car keys or a laptop would I be transferring virus onto those items and if so would there be enough virus on those items to cause infection."

[evan_au]

In theory, a very light touch could transfer viable virus from a surface to your hand, and then onto your keys.

In practise:
- COVID virus tends to become non-viable after a day or two at room temperature, indoors. It breaks down in hours in sunlight, outdoors.
- washing your hands after being outside, and before eating will reduce this risk significantly
- COVID spreads very easily through the air - a human breathes in about half a cubic meter of air every minute, and some of that inhaled air has been exhaled by someone else.
- OMICRON variant is more easily breathed out by infected people
- So your best protection is masks, social distancing and ensuring good turnover of air indoors.

[Jimbo84]

(This post was set up as a response to some questions that I emailed to the scientists) There might be some confusion in the questions. What I am trying to find out is this. I understand that if an infected person was to cough or sneeze on an object or their hand and then touch an object, for example a door handle, and then another person was to touch that object (door handle) and then touch their eyes/nose/mouth etc that theoretically they might be able to contract the virus. In reality I understand this might not be the case or the odds might be quite high as there are other external factors such as viral load, temperature, sunlight etc, but what I am trying to find out is if I was to touch the infected door handle and then touch a second or third item such as another door handle or set of keys etc, would I be transferring enough viable virus onto the second and third surfaces to cause anyone who may in turn then touch these surfaces and their eyes/nose/mouth etc to get infected or is this just theoretical or is this reality, I mean surely there would be other factors that come in to play that would reduce the amount of virus as it travels (purely by touch) from one surface to another.

[Colin2B]

(This post was set up as a response to some questions that I emailed to the scientists) There might be some confusion in the questions. .........
.........surely there would be other factors that come in to play that would reduce the amount of virus as it travels (purely by touch) from one surface to another.

Hi, welcome to the forum and thank you for following up your question.

Yes, you are right. If you touch any surface coated with a substance then some will transfer to your hands, but some will remain behind reducing the amount transferred.
The final amount of virus on any surface you touch will depend not only on the original amount, but on how many times it has been transferred.
Given the factors you and Evan mention there is unlikely to be much viable virus after a few transfers. Unfortunately it appears that Covid 19 doesn’t need much virus to get into the system to set off an infection, so there really are no guarantees.

[evan_au]

Pathogen transfer by contact is called "Fomites".
The most likely place for pathogens to end up is on your hands.
And the most likely way to transfer to someone else's hand is via handshakes.
And some politicians just love "pressing the flesh"...
See: https://en.wikipedia.org/wiki/Fomite

[Bored chemist]

Outside of a susceptible host, a virus is essentially a spec of dust.
So, if it's possible to transfer a dust mote via some pathway, then it is possible to transfer a virus that way.
Once it reaches a potential host, the question is essentially "Does the virus get lucky?"
If it does the the person gets infected.

[Jimbo84]

Thanks very much for taking the time to reply. I had read plenty of articles online regarding the subject as unfortunately I am one of those people who spends hours constantly cleaning every surface that I have touched and either sanitizing shopping and parcels or putting them in quarantine for a few days. Some articles I have read are quite general and they only seem to focus on the theoretical possibility where as others (such as Emmanuel Goldman) say that there is very little risk. For some reason (I think I have a mental block) I can't seem to touch any surface that may have been touched by somebody else without feeling the need to clean my hands before touching something else, I think I was just looking for reassurance to maybe take a few risks and try to get back to some sort of normality.

[evan_au]

I am one of those people who spends hours constantly cleaning every surface

This sounds like a variety of "obsessive compulsive disorder".
- If you find that it is interfering with your life, you can talk to a therapist about it.

It is sensible to avoid dangerous pathogens (like Delta strain of COVID) - but sometimes the safest way to avoid pathogens is to immerse yourself in a variety of helpful bacteria (eg in yoghurt, kimchi, getting a dog, or rolling in the grass, sometimes).

https://en.wikipedia.org/wiki/Obsessive%E2%80%93compulsive_disorder