It takes only a small number of Norovirus viral particles to make you sick – as few as 10 Norovirus particles can make an adult sick. The average Norovirus virus is around 35 nanometers across — one-third the size of most viruses — so the volume of an infectious dose is very small.
Norovirus is persistent. People infected with Norovirus continue to shed it for up to three weeks, long after the vomiting and diarrhea have passed.
Norovirus can be passed a surface to hand to mouth. You can also inhale the Norovirus.
For more information about Norovirus, visit http://www.about-norwalk.com/