The Norovirus is a group of viruses that cause gastrointestinal upsets. It is common enough to have been reported 23 million cases of. More than half of which was food-borne, meaning the Norovirus came from food, transmitted fecal-orally.
Now, that is gross. It could mean the person who prepared your salad didn’t wash their hands. Food that is infected by its handlers is usually the ones that are prepared right before consumption, like salads or sandwiches. Fresh fruits can also become a source if the water they were rinsed in was infected.
Norovirus getting into your drinks or sauces is not as big an issue, as it allows for even mixing. You are not as likely to get a big clump of virus in your drink as in your salad. Poor Sanitation makes a lot for illnesses, food borne or not.
This is complicated by the many public areas, as these facilitate spread. The rails in the stairs, the doorknobs to the toilet can all be lined with the Norovirus. When the virus gets into you, you’ll get stomach cramps, diarrhea and vomiting. Unlike bacteria that you can drink antibiotics for and be done with, viruses are generally left to run its course. (This one’s a 48-hour one.) And besides, there isn’t a drug specifically made to kill the Norovirus.
The current treatment is supportive. Intravenous fluids are given if you catch the really virulent one and the diarrhea and vomiting are depleting your body fluids. You can also re-hydrate yourself by taking in more fluids, of course. Have some soups and fruit juices (without the pulp. The pulp will only make you go again). Sports drinks are made differently, therefore, you can’t rely on them completely.
The single most effective way to guard yourself against the Norovirus is by hand washing. Most of us don’t exactly scrub long enough, and rinsing takes only a few seconds. But it has to be at least 15 seconds, with vigorous rubbing. You’d figure being a little anal is good for your health too.