Norovirus. The characteristics of norovirus itself, the presentation of symptoms and people affected, as well as the exposure pathways are all factors that contribute to the contamination and spread of norovirus as a foodborne illness. Norovirus is highly contagious and causes gastroenteritis, vomiting, and diarrhea (4). A member of the Caliciviridae family, norovirus is also divided into six genogroups and 31 genotypes (5, 6). The most common cause of human illness is due to noroviruses in genogroup II, genotype 4 (5). Only a few viral particles, as few as 20, are needed to cause illness and illness can be acquired from simple proximity to a sick person that has vomited (5). Proximity to another sick person is not the only way norovirus can be acquired. People can also get norovirus from contaminated surfaces, food, and water. In fact, norovirus is the primary cause of foodborne outbreaks in the United States. It causes at least 20 million illnesses every year, yet this is likely an underestimate because norovirus is commonly not reported (4, 6). Symptoms attributed to norovirus are typically mild, but global burden is high (7). Norovirus accounts for 18% of gastroenteritis cases globally (8). The majority of norovirus illnesses in the U.S. are related to foodborne outbreaks and the majority of foodborne outbreaks are caused by infected food workers (4). The foodborne outbreaks of norovirus due to infected food workers are preventable. Over half of norovirus outbreaks caused by infected food workers are due to handling food without gloves, and about 20% of food workers report coming to work while sick because they fear repercussions (4). This food preparation step of the food production chain is the easiest to observe and pinpoint paths of potential contamination, but to thoroughly address foodborne illness, we need to study all steps of the production chain.
Norovirus. Salmonella Typhi (typhoid fever)
Norovirus. Globally, norovirus is estimated to be the most common cause of acute gastroenteritis across all age groups, being associated with approximately one-fifth of all cases of acute gastroenteritis (4). Worldwide, norovirus is estimated to be responsible for 685 million cases of acute gastroenteritis every year, 200 million of these cases are among children younger than 5 years old, leading to an estimated 50,000 child deaths each year (5). Each year in the United States, norovirus causes an estimated 19-21 million cases of acute gastroenteritis, leading to 1.7-
