
Norovirus was recently approved as the official genus name for the group of viruses provisionally described as “Norwalk-like virusesâ€. Noroviruses are viruses that cause acute gastroenteritis (stomach flu) in humans. Viruses are very different from bacteria and parasites, some of which can cause illnesses similar to norovirus infection. Like all viral infections, noroviruses are not affected by treatment with antibiotics, and cannot grow outside of a person’s body.
The symptoms of norovirus illness usually include nausea, vomiting, diarrhea, and some stomach cramping. Sometimes people have a low-grade fever, chills, headache, muscle aches, and a general sense of tiredness. The illness often comes on quickly, and the infected person may feel very sick. In most people the illness is self-limiting with symptoms lasting only about 1 or 2 days. In general, children and the elderly experience more vomiting than adults.
People may feel very sick and vomit many times a day, but the illness has no long-term health effect. However, sometimes people are unable to drink enough liquids to replace the liquids they lost because of vomiting and diarrhea. These people can become dehydrated and may need special medical attention. This problem with dehydration is usually only seen among the very young, the elderly, and persons with weakened immune systems.
People can become infected with the virus in several ways. Eating food or drinking liquids that are contaminated with norovirus, touching surfaces contaminated with norovirus, and then placing their hand in their mouth are both ways to contract the illness. Also, having direct contact with another person who is infected and showing symptoms, for example, when caring for someone with the illness.