I think noro season came late this year which is why it's hanging around into March, normally it's rife around Christmas in my area but didn't show its ugly face until late January. I also read the hpa reports that come out every Thursday on the government website, you can also check how your local hospital is coping with noro virus and how many cases they have had in the previous week if you go on the bbc website and type in nhs, you then type in your postcode and it gives you all sorts of info about your local hospital.