Due to a fear of job loss and not wanting to leave co-workers short-staffed, one out of every five restaurant workers has reported going into work while sick with vomiting or diarrhea. A recent Vital Signs report issued by the Centers for Disease Control and Prevention has revealed that the food service industry to is to blame for 64 percent of norovirus outbreaks in the United States.

“It is vital that food service workers stay home if they are sick; otherwise, they risk contaminating food that many people will eat,” Dr. Aron Hall of CDC’s Division of Viral Diseases said in a statement. “Businesses can consider using measures that would encourage sick workers to stay home, such as paid sick leave and a staffing plan that includes on-call workers.”

According to the CDC, norovirus is a highly contagious virus usually spread through close contact with an infected person, contact with a contaminated surface, or through contaminated food or water. People suffering from norovirus experience inflammation of the stomach or intestines, also known as acute gastroenteritis. Norovirus is the most common cause of acute gastroenteritis and food-borne illnesses in the United States, contributing to 19-21 million illnesses, 56,000-71,000 hospitalizations, and 570-800 deaths.

Researchers used the CDC’s National Outbreak Reporting System (NORS) to analyze norovirus outbreaks reported by both state and local health departments between 2009 and 2012. The investigation also included which types of food were commonly associated with norovirus outbreaks. Health departments around the U.S. reported 1,008 norovirus outbreaks that were caused by contaminated food, the majority of which were tied to restaurants and catering/banquet facilities. Out of 1,008 norovirus outbreaks caused by the food service industry, 520 included factors contributing to the food contamination.

Infected food service workers accounted for 364 outbreaks, including 196 cases that involved workers touching ready-to-eat food, such as washed raw fruits and vegetables for salads and sandwiches, with their bare hands. Out of 324 outbreaks that included a specific food item, 90 percent were contaminated during final preparation and 75 percent were due to raw food. The most common food items tied to outbreaks included leafy vegetables, fruits, and oysters.

“Norovirus outbreaks from contaminated food in restaurants are far too common.” said CDC Director Dr. Tom Frieden. “All who prepare food, especially the food service industry, can do more to create a work environment that promotes food safety and ensures that workers adhere to food safety laws and regulations that are already in place.”

To help prevent against norovirus outbreaks that are caused by contaminated food, the CDC recommends food service workers wash their hands before and after handling food and that they use utensils and disposable gloves when handling ready-to-eat foods. Restaurants should consider certifying kitchen managers and training food service workers in food preparation safety. Policies that require sick workers to stay at home until 48 hours after symptoms have stopped should also be established.