Norovirus is a nasty little virus that causes tons of misery every winter. It is an RNA virus that infects the gastrointestinal tract causing violent vomiting and diarrhea. About 12 to 48 hours after being infected, rapid symptom onset will lay you flat for about a day. Even better, immunity to this virus fades in a few months and you are susceptible to a new attack. A particularly nasty strain of norovirus has been circulating in my area and my family came down with it just this weekend. The virus is highly contagious, with only 10 virus particles ingested in the mouth being able to cause disease. Much to my surprise, neither my son nor I became ill. This got me wondering why? Follow the link to learn the answer to this story.