Ayyemmeff, there have been documented Norwalk outbreaks all over the world since about May of this year. In Canada, on the east coast of the US, all over the UK, on passenger cruise ships, among British troops in Afghanistan, and in a hotel in New Zealand, just to name a few. Only the common cold is reported more frequently. It's traditionally thought of as a food- or water-borne illness but recent outbreaks are being attributed by the CDC
to person-to-person contact, or person-object-person. Therefore, just as in the common cold, THE most effective prevention is good handwashing, particularly after using the loo.
No one really knows how long the organism lives on surfaces, which is a huge problem for disinfection. Generally the only substances that are known
to kill Norwalk are chlorine bleach in high concentrations (5000 parts per million) or a couple of commercial products, including this one
and this one
Isolation IS effective--but what's difficult is getting people to understand that affected persons continue to shed the virus in their stool (and are therefore infectious) for at least 72 hours (and it may be as long as a week) AFTER the cessation of symptoms. So ill persons need to be isolated for at least 72 hours after they are symptom-free.
Treatment is symptomatic only, as the virus is self-limiting. Onset of symptoms is 24 - 72 hours after exposure; symptoms generally last 24 - 60 hours.
Some more info here
Feel free to PM me if you need any more info. Good luck!