Norovirus to Blame For Majority of Food-borne Illness

The leading cause of disease outbreaks from contaminated food is Norovirus, according to a CDC report. The virus, which infects around 20 million people a year, is able to spread anywhere food or people congregate. Norovirus is highly contagious and causes diarrhea and vomiting in those who catch it. The impact it has on physicians and hospitals is dramatic, as it leads to almost 2 million outpatient visits, 400,000 emergency room visits, 60,000 hospitalizations, and between 500 and 800 deaths a year. However, the most important fact about norovirus doesn’t come in a numerical form; what the CDC wants people to know most about the virus is how easily preventable outbreaks are.

Stay Home

Infected food workers are responsible for causing 70 percent of Norovirus outbreaks, according to a CDC Vital Signs factsheet. Yet, the CDC’s reports on the virus suggest it doesn’t have to be that way. A large part of the CDC’s solution for prevention is to have people stay home when they are sick. One in five food service workers have reported going to work while they were sick with vomiting or diarrhea. When food workers make the decision to come to work sick, they are putting their coworkers and the public at risk. While those workers are partly to blame, some of the responsibility for keeping sick workers home falls on their employers. Many foodservice workers are unwilling to miss work out of a fear of job loss, a concern that employers are in a unique position to remedy. One CDC solution, proposed by Aron Hall, D.V.M., M.S.P.H., of CDC’s Division of Viral Diseases, is to have policies that favor having sick employees stay home, like on-call staffing and paid sick leave.


Apart from people, there are some specific foods, things, and places that are often major factors in outbreaks. Leafy greens (lettuce), fresh fruit, and shellfish (particularly oysters) are three of the leading culprits. However, other raw foods, and foods that are handled after cooking, still present a potential threat when it comes to transmitting the Norovirus. The CDC says that most contamination is happening in the final stages of food preparation, often when raw and cooked ingredients are combined. Pools, schools, summer camps, and water wells have all been factors in past outbreaks. The CDC says cruise ships are likely the place that most people encounter the name, Norovirus; however, those outbreaks only account for about 1 percent of all reported cases.


Outbreaks of viruses like the Norovirus are a reminder that programs like the CDC’s National Outbreak Reporting System (NORS) are important tools that local, state, and territorial health departments need to seriously implement so that manageable diseases can become more manageable. The FDA has a similar tool, called the Coordinated Outbreak Response and Evaluation Network (CORE), designed to aid in response and evaluation of human, animal food, and cosmetic related disease outbreaks. In a similar vein, the FDA model food code is an attempt to assist state and local jurisdictions in developing food safety policies and laws that can mitigate the effect of harmful contaminates like the Norovirus.

CDC Initiative

In addition to recommending that state and local governments implement the FDA’s model food code and use its reporting tools, the CDC recommends that the federal government assist states and local governments with funding to enhance outbreak reporting and investigation programs. The CDC also urges employers to obey federal food safety law, to train food workers, and to certify kitchen managers in food safety. As for food service employees, in addition to staying home, the CDC recommends clean surfaces, clean hands, disposable gloves, and communication to managers about illness as essential parts of outbreak mitigation. There are a lot of tools in the CDC’s and FDA’s arsenal to help employers, employees, and state and local governments in their battle with the pervasive virus. Whether it is through regulation or common sense, with some planning, the norovirus could become a thing of the past.

The CDC also maintains a public database for outbreaks of foodborne illnesses where Norovirus outbreaks can be monitored and followed.