After sickness question

[sadiemay123]

I've read that people can carry norovirus in their stool for up to like 2 weeks. Is that really true, or have I been worrying all this time for nothing!!

[Chronicles]

This is true, but unless they actually touch their poop and make you eat it, thre's no way you could get it. Most people wash their hands anyways.

[SilentFrog]

Ah, now you see that is kind of a 'half truth'. It is true that the norovirus can be shed in a persons stool for up to two weeks after their initial infection, but what they won't tell you outside of the scientific publications is that these viruses are probably not still capable of infection. You see, once your body's immune system gets to work, it starts damaging the viruses that it comes across and of course preventing them from infecting new cells. As time goes on, more and more of the viruses that are inside your body are 'deactivated' and they naturally find their way into the persons stools. And so you see, really after about 48 hours or so the level of virus particles in the persons stools is actually quite low, and of the particles that may remain in the persons stool, many of these virus particles will really be 'deactivated', that is to say that if you were unlucky enough to get them into your bloodstream, they wouldn't be able to infect any cells.

But as Chronicles says, that is all assuming that you are dealing with somebody who goes to the toilet and doesn't wash their hands. Now, how many people really don't wash their hands after 'pooping'? It would be disgusting not to, even the most disgusting of people are bound to wash their hands after 'pooping', so your risk of picking up any of these particles is quite low anyway, not to mention what I said above. So in short, don't allow yourself to be misled by what you read online.

It's true that norovirus particles might have been "detected" in stools for up to two weeks after the initial infection, but what you won't read on most websites is that the tests used in that study don't allow you to see whether the viruses are still capable of infection or not, and we know from looking at data gathered during outbreaks that they probably aren't. In fact, after the first 48 hours have passed since the person last showed symptoms, they become much less contagious. No need to avoid people for two weeks after they're ill, after 48 hours they'll be pretty safe to be around

Hope that helps somewhat

[Tasmith]

Silent frog, I really like reading your responses. Where do you get all of your information?

[SilentFrog]

Hi Tasmith, thank you again for such a compliment, I'm glad you like my responses! My information regarding viruses and bacteria in general comes from my knowledge of virology (a hobby of mine), I like to keep up to date with the literature and various studies and a couple of times a month I visit a friend who lets me into his teaching lab and we grow cultures and observe them, so that all helps. If I'm not sure of something, I'll generally look it up to check that it's correct, here's one resource I use

[Tasmith]

That's interesting. Too bad you and your friend can't do some observations on the norovirus. Is love to see with my own eyes what kills it and how long it can live on hard/soft surfaces.

[SilentFrog]

I've not actually had the pleasure of observing any SVs under the microscope since in order to see viruses (which are a fraction of the size of bacteria) you need a very powerful microscope (a Scanning Electron Microscope) and it takes more time to set up and prepare the samples etc, so I've been limited to joining a few of his classes and observing with the rest of the students and observing whatever specimen is there. I've seen one of the Astrovirus types, I can't remember which one exactly. Certain types of Astrovirus can cause stomach upsets but the one I looked at infected birds. Still really interesting though

Standard bleach (Sodium Hypochlorite) will kill the norovirus within seconds to minutes (depending on the concentration), Benzalkonium Chloride which is commonly used in disinfectants and some hand sanitizers has some effect in reducing the number of viral particles, Isopropyl Alcohol (rubbing alcohol) on it's own is useless but when combined with certain other compounds has been shown to kill norovirus (we're talking surrogates here btw, so Feline Calicivirus, Murine Norovirus etc), so there are solutions out there that kill Norovirus

As for living on surfaces, that's a more complicated question, undisturbed it can live on hard surfaces for up to 2 weeks, soft surfaces are slightly different because the virus particles sink through into the porous material which can make it harder to pick the virus up (eg: by touching). Believe it or not there are also something called "droplet nucleotides" which are tiny, tiny virus particles which are so light that they can - in certain conditions - float in their air indefinitely (although the virus itself would degrade and 'die' after a certain period of time so wouldn't infect you). This is all purely theoretical though, we don't have any concrete studies suggesting that Norovirus particles float through the air infecting people, we just assume it's 'theoretically possible'. The truth of the matter is that the vast majority of infections can be traced to droplets having settled on surfaces or food which has been eaten leading to infection.

So washing your hands and disinfecting surfaces is the most effective way we know of (short of a vaccine) to prevent yourself from getting noro.