More than 100 students at St Nicholas Junior School in Dereham were either absent or sent home suffering from a gastrointestinal infection Thursday, according to a EDP24 report Friday.

The exact etiology of the outbreak has not been determined; however, the symptoms, diarrhea, vomiting, nausea, fever and headache, resemble those of norovirus.

Neil Toplis, headteacher at the school said in a letter to parents:

Should your child show any signs of developing this illness we would advise you to keep them at home. If your child has had any sickness or diarrhoea, please ensure that children are clear of symptoms for a full 48 hours before returning to school. This is in line with our school policy and Health Protection Team guidance.

The outbreak mostly affected children ages 8 & 9, while some faculty have also been affected. The school was cleaned and sanitized Thursday.

Norovirus is a highly contagious viral illness that often goes by other names, such as viral gastroenteritis, stomach flu, and food poisoning.

The symptoms include nausea, vomiting, diarrhea, and some stomach cramping. Sometimes people additionally have a low-grade fever, chills, headache, muscle aches, and a general sense of tiredness. The illness often begins suddenly, and the infected person may feel very sick. In most people, the illness is self-limiting with symptoms lasting for about 1 or 2 days. In general, children experience more vomiting than adults do.

Norovirus is spread person to person particularly in crowded, closed places. Norovirus is typically spread through contaminated food and water, touching surfaces or objects contaminated with norovirus and then putting your hand or fingers in your mouth and close contact with someone who is vomiting or has diarrhea. For more infectious disease news and information, visit and “like” the Infectious Disease News Facebook page

Norovirus causes more than 20 million illnesses annually, and it is the leading cause of gastroenteritis outbreaks in the United States.