Two outbreaks this week are a good example of why norovirus is the leading cause of food poisoning outbreaks in the U.S. One was at a Ground Round restaurant in Minnesota, the other was at an elementary school in Indiana.
Norovirus is highly contagious virus that affects about 20 million Americans each year. The amount of virus that fits on the head of pin, as few as 18 particles, is enough to make 1,000 people sick, according to the Centers for Disease Control and Prevention (CDC), which has compiled a norovirus fact sheet with the following information.
Although it is sometimes called “the cruise ship virus,” only about 1 percent of norovirus outbreaks take place on cruise ships. Most, about 65 percent, happen at restaurants and originate from an infected food worker.
Symptoms of norovirus are vomiting and diarrhea. When someone is sick, they can shed billions of viral particles in their stool and vomit. The virus is easily transmitted in shared spaces that are not carefully and thoroughly cleaned. A person with norovirus is most contagious while they are experiencing symptoms but may also infect others before symptoms start and after they resolve which is why public health workers urge sick restaurant employees to stay home if they are sick.
Norovirus is hard to kill and can remain on foods even at temperatures below freezing and above 140°F. It can survive of on countertops or utensils for up to two weeks. It can also resist many common disinfectants and hand sanitizers.
