Noroviruses, also called Norwalk-like viruses and caliciviruses, is a common type of foodborne illness that causes what is commonly called the stomach flu. The CDC (Center for Disease Control and Prevention) estimates that 23,000,000 are affected by the virus each year. Symptoms of an infection, which usually begin within 48 hours of contact with the virus, are primarily gastrointestinal, including nausea, vomiting, diarrhea, and abdominal cramping and bloating. Other symptoms include a slight fever, chills, tiredness, headache, and sore muscles. These typically last no longer than two days and affect children more severely than adults.
Noroviruses are extremely contagious. They are present in the stool and vomit of infected persons and are usually contracted via the fecal to oral route. Group settings (schools, nursing homes, summer camps, cruise ships, etc) are particularly susceptible to the rapid spreading of the virus. Common means of contracting the infection include:
- Direct contact with an infected person (it is often contracted while caring for an ill person)
- Placing fingers in or near the mouth after touching a surface that has been contaminated
- Consuming raw or improperly steamed shellfish (clams or oysters) harvested from contaminated water
- Consuming foods prepared by infected persons, particularly if they do not wash their hands after using the bathroom
There is no direct method of treatment because no antiviral medication exists. Antibiotics do not work because norovirus is a viral infection and they can only aid in fighting bacterial infections. Steps can be taken to combat the effects of dehydration, which often occurs during infections due to vomiting and diarrhea. The best means of doing this is to drink a lot of water or juice. Contrary to common opinion, drinking sports drinks is not better; they do not replace nutrients lost while battling the infection. Dehydration is the most serious complication that arises from norovirus infections and can result in hospitalization, particularly for elderly persons and children.
Prevention of infections involves good hygiene and basic sanitary measures. Some common sense steps include the thorough washing of hands after any fecal contact (going to the bathroom, changing diapers), washing hands before preparing or eating food, washing fruits and vegetables before consuming, properly steaming shellfish before consuming, disinfecting areas that may have become contaminated, and the prompt washing of clothing and linens that may be contaminated. Also, infected persons should not prepare food for at least three days following recovery.