Norovirus causes more food poisoning outbreaks than any other pathogen and most of those outbreaks occur at restaurants, according to a new report from the Centers for Disease Control and Prevention (CDC). Restaurants were the source of almost two thirds of all foodborne norovirus outbreaks between 2009 and 2012. The reason? Sick employees working and not taking time off.
About 70 percent of norovirus outbreaks at restaurants originate from a sick food worker. Norovirus, which is highly contagious, is usually spread via the fecal-oral route, meaning an infected person didn’t wash his or her hands properly after using the restroom and then contaminated various surfaces or foods by touching them. The contaminated foods are then eaten by customers who become ill. This is how almost 20 million Americans contract norovirus every year, although it can also be spread “through incidental ingestion of vomitus droplets, which can disperse via aerosolization,” according to the CDC.
Symptoms of a norovirus infection include vomiting and diarrhea; a lot of vomiting and diarrhea that usually occurs over a short time span. A person who has the virus is contagious for up to three days after symptoms resolve and should remain at home during that time period. But most people don’t.
Of the 20 million Americans who get norovirus each year, between 1.7 and 1.9 million will see a doctor on for an outpatient visit, 400,000 will go to the emergency room, between 56,000–71,000will be hospitalized and 570–800 will die. Those most at risk for the worst outcomes are children under five, seniors and those with compromised immune systems.
Careful hand washing is the best way to reduce exposure to the virus. Alcohol-based hand sanitizers can be uses in addition to hand-washing, but should not be considered a replacement for it.
Of the 1,008 foodborne norovirus outbreaks that were studied, a foods source was identified in 324. In most cases the food was contaminated during preparation. from bare-handed contact by an infected worker. Leafy vegetables were imlicated in 30 percent of outbreaks, fruits in 21 percent and mollusks in 19 percent.
Targeting food workers with information about norovirus would have “substantial potential for prevention of norovirus transmission,” the authors concluded.
