Are there any treatments for norovirus infections?
There is no real treatment. The best advice is to drink a lot of fluids. If you keep rehydrating, most people get better in 48 to 72 hours.
What is the best way to avoid it?
Don't eat foods that are high-risk, such as oysters, which are sometimes harvested in water contaminated with human fecal matter. You should also wash your hands with hot water and soap before eating to prevent infection in yourself, and wash your hands after using the bathroom to keep from spreading it to others. We don't know if alcohol-based hand-sanitizers are effective, so it's safer to wash your hands.
Does norovirus affect other animals?
There is a norovirus in mice that causes encephalitis (inflammation of the brain), and researchers have found noroviruses that cause intestinal flu in pigs, cows and lions. So far, none of these animal noroviruses have been shown to infect humans.
Is norovirus becoming more common?
It's possible that there are more cases now than in the past because of the way food is prepared and distributed—one contaminated person at a restaurant or take-out service may be preparing food for hundreds of people in one night. But we have also gotten much better at detecting it, which might explain the apparent increase in numbers of cases reported. In 1990 researchers sequenced the virus's genome, and since then we have developed tests to detect the virus in a person's stool.