The most common foodborne illness in the United States—the “Norovirus”—is the cause of an estimated 21 million infections, 70,000 hospitalizations and 800 deaths per year in the U.S. Norovirus is highly contagious and can be transmitted from one infected person to another although the virus is usually contracted by exposure to contaminated food or water. Those exposed report flu-like symptoms including nausea, vomiting, diarrhea, low-grade fever, cramping, headaches and body aches. Symptoms can persist for up to three days in a healthy person and up to six days in individuals who are at higher risk for infection, such as children, the elderly and the immunocompromised. Hospitalization can result from the severity of the symptoms alone and even from dehydration caused by the symptoms.
How Norovirus is Contracted
Norovirus is most commonly contracted by ingesting contaminated food. Improperly washed or unwashed fruits and vegetables are potential carriers of the virus. In addition, shellfish is a common source of infection because steaming (common in the preparation of shellfish) does not heat the food enough to kill the virus. Norovirus can survive in temperatures up to 140 degrees.
Norovirus transmission can also arise from food-handling surfaces that are not properly disinfected. If a food-handling surface is contaminated by a food product containing the virus, the virus can transfer to foods placed on the same surface. Outbreaks have occurred from contaminated food processing facilities, such as those producing deli meats. Likewise, if food is prepared by an infected person, the infected person may contaminate the food, especially when the person has improperly washed and sanitized their hands.
Outbreaks have also been caused by contaminated water. Previous outbreaks were found to be caused by food irrigated with or grown in water contaminated by sewage, such as raspberries and oysters. Additionally, drinking water has also been found to cause outbreaks of infection in particular communities, either when the community’s water source has been contaminated by a septic tank leak or when a municipality’s water treatment facility did not fully disinfect the water.
Persons & Communities Most Commonly Affected by the Norovirus
Although Norovirus can be contracted by anyone, some individuals are more susceptible due to their age, health, environment or the communities in which they live. Children, the elderly and people with weakened immune systems are susceptible to more serious and longer lasting symptoms. Deaths most commonly occur among the elderly.
Outbreaks of Norovirus occur most frequently in nursing homes. Certain environments are ripe with potential for infection, such as hospitals, schools, child-care centers, prisons and military bases. Outbreaks also regularly occur in certain vacation and social settings, such as cruise ships, and among attendees of specific events and restaurant patrons. For an unexplained reason, Norovirus infections occur more often in the winter. If you or a loved one begin to show symptoms of food poisoning, it is important to contact a medical professional.