Norwalk virus or norovirus is a virus which is causes gastroenteritis, an inflammation of the gastrointestinal system. It is estimated that noroviruses account for around 50% of intestinal complaints worldwide every year, making it highly likely that you have had a personal encounter with Norwalk virus. As a general rule, this virus is self limiting, which means that it will resolve itself within a few days of infection, although the infected individual may not feel very pleasant during this process.
The Norwalk virus is named for an infamous school outbreak which occurred in Norwalk, Ohio. The virus is part of a much larger family known as Caliciviridae; norovirus has a characteristic round structure which makes it very easy to identify. Unfortunately for humans, this virus is extremely contagious, making it difficult to control once an outbreak occurs.
Infections with Norwalk virus usually result in nausea, vomiting, diarrhea, and stomach cramping. People may also feel sluggish or dizzy. Many people call a Norwalk virus infection the “stomach flu,” in a reference to the general sense of malaise which accompanies it. Within one to two days, the infection typically goes away on its own.
Treatment for infection with Norwalk virus is primarily focused on fluid replacement, ensuring that the patient stays healthy. Drinking liquids like water, tea, and juice can help; in extreme cases, intravenous fluids may be offered. Patients are also encouraged to rest and eat mild foods which are easy to keep down. Infected individuals should also try to minimize contact with those not manifesting symptoms, to reduce the risk of transmission. The use of chemicals like bleach to wipe down surfaces is also recommended.
There are a number of ways to get Norwalk virus. Many people get it from touching infected surfaces, like doorknobs handled by people with the virus. It can also be contracted through close contact with an infected individual, and through eating contaminated food. Certain foods are especially prone to contamination, like salad greens, which are not cooked before being served, and undercooked shellfish and meats.
Because Norwalk virus is so contagious, it often shows up in crowded environments like schools, prisons, and cruise ships. Several cruise ship companies have struggled with outbreaks of the virus, which can quickly sicken everyone on board a ship as people eat the same food and share a wide number of surfaces ranging from deck chairs to doorknobs.