Confused. :S

[Rls1994]

This is about how long noro lives on surfaces. I know from v* and d* particles it lasts up to two weeks on a surface, but how long when someone infected just touches a surface? I heard it's only about three days but is that true? Thanks!

[Cynna]

From what I understand the first three days you are the most contagious after being sick. From day 3-10 the risk goes down. I have heard conflicting reports about whether someone has enough of the virus left in them to infect another person from day 3-10.

[Arkham_Patient]

No one apparently knows how long it truly lasts on surfaces because they have a hard time being able to test it in a petri dish. The tests they have done are with surrogate viruses like FCV which is what causes respiratory infection in cats but is apart of the family. I have heard stories of people coming to other people's houses a week after they've been sick and have come down with it but I haven't heard of any stories after that.

[Cynna]

The virus is able to survive relatively high levels of chlorine and varying temperatures. Noroviruses can survive on practically any surface including door handles, sinks, railings and glassware. On hard surfaces in the environment, they have been found to survive for up to 12 hours. On contaminated carpet, noroviruses have been found to survive for up to 12 days.

That was from the Canadian Gov't.

[AoD]

First of all, a sick person does not contaminate surfaces through their skin by simply touching it. They contaminate them by touching a surface contaminated by their v* or d* and then touching the surfaces (so the skin picks up the virus and deposits it somewhere else where it's just waiting to be picked up by someone else). That whole virus transfer thing can happen 8 times in a row before there's not enough virus to transfer anymore. So if someone who is sick has been washing their hands properly, they're not necessarily gonna contaminate everything they touch. They test its presence on surfaces with PCR amplification, which doesn't meant it is still able to infect people but merely means there is a detectable quantity. Most probably it does remain virulent though, it's a tough virus. Most reliable sources list a survival time of 12h on hard non-porous surfaces, up to two weeks (but quite possibly more) on fabrics. The three days timeframe you refer to is the average time someone sheds the virus through their stool (but it can be up to two weeks), but even if someone doesn't shed the virus anymore and there's still viral particles in their home (let's say on the couch) someone can still pick up the virus on their hands by touching that surface even if the person isn't shedding. Makes more sense?