I have seen a lot of patients in recent weeks with complaints of “stomach flu”. Just to be clear the “stomach flu” really is not FLU at all and has nothing to do with “flu/influenza”. The stomach stuff is actually called gastroenteritis, and is typically caused by a virus. If you have been watching the news, you have heard about yet another cruise ship where many passengers and crew have been sickened and the boat had to return to port.
Most gastroenteritis causes vomiting, diarrhea, and stomach cramps. It is pretty miserable. The most common cause of the stomach “bug” is a virus called norovirus. Norovirus is now the most common cause of gastroenteritis in the United States. Rotavirus was previously the most common cause of viral gastroenteritis, but since the rotavirus vaccine has been introduced for infants, rotavirus has now been surpassed by norovirus. Viruses are really smart, sneaky and strong (which is called virulent in medical terms).
Norovirus makes you feel awful (who likes to vomit?) and is very easy to pick up. Where it takes exposure to many viral particles to get sick from some viral illnesses, a recent study in The New England Journal of Medicine found that as few as 10-100 norovirus particles may cause disease. It is a very efficient virus and may even be acquired by breathing in the viral particles. (gross example, someone vomits and you are in the room and breathe the virus - think about your child spewing vomit).
Norovirus peaks in the 6-18 month old child. By 5 years of age 1 in 6 children will have seen their doctor for vomiting/diarrhea caused by norovirus.
The key to combating norovirus is hydration. The virus typically lasts several days with vomiting usually shorter than the diarrhea. Treat vomiting with frequent sips of clear liquids and increase the volume of liquid over time. Once your child is tolerating liquids and vomiting has stopped you can let them eat. If your child is over the age of 1 year and diarrhea is a big problem, I would restrict dairy for a couple of days as well. Probiotics may help as well.
Knowing that norovirus can be transmitted by hand to mouth as well, good hygiene is important....especially after the bathroom...so make sure those little hands are washed.