Baby Stomach Virus Contagious To Adult Is A Stomach Virus Inevitable?

Is a stomach virus inevitable? - baby stomach virus contagious to adult

See, my husband, son and I live with my father, mother, sister, brother and her baby. My father and my nephew both have symptoms of a stomach virus. The symptoms began to appear Monday morning for my nephew and my dad last night. My nephew has a fever. My father did not. Both were vomiting and both diarheah (or how to spell the word Hell)

Questions:
"If the virus when they most contagious? Are you the most contagious before or after the symptoms, or have both, or neither?
- How long incubation period for stomach virus?
"Can not vaccinated against influenza to help my child, get it?
How can the difference between food poisoning and a viral infection?
-How the virus will spread to the stomach?

My BIG concern is that we're going on vacation next week, and I would my child gets sick, like. When you contract the virus, do you think you are doing and next week? Oh, please say yes. I'm going crazy here!