Norovirus causes about one fourth of all food poisoning cases in Canada each year, according to a new study published in the May issue of the journal Foodborne Pathogens and Disease. About 4 million Canadians, one in every eight, are sickened by food poisoning each year, according to the study. Norovirus is also the leading cause of food poisoning in the U.S. where one in six people, or about 48 million, are stricken by foodborne illness each year.
The Canadian study looked at illnesses reported from a variety of sources including: the Canadian Notifiable Disease Surveillance System, the National Enteric Surveillance Program, enhanced national listeriosis surveillance, the provincial reportable disease surveillance system, national studies on gastrointestinal illness and C-EnterNet surveillance. Most of the illnesses reported, about 60 percent of them, were from unspecified agents.
The 40 percent of illnesses with known sources were caused by 30 pathogens. Of the 1.6 million illnesses with known causes, norovirus caused just over 1 million illnesses, Clostridium perfringens caused 177,000, Campylobacter caused 145,000 and Salmonella caused 88,000. Compared with the baseline period 1998-2000, these numbers show “no significant change” in the rate of Salmonella infection, a 35 percent decrease in the rate of campylobacteriosis, a 65 percent decrease in the rate of infections form Shiga toxin-producing E.coli.
Symptoms of norovirus diarrhea, vomiting, nausea and abdominal cramps which usually last usually last 24 to 48 hours. Sometimes these symptoms may also be accompanied by low-grade fever, chills, headache, muscle aches, and general sense of fatigue. It can cause severe dehydration which requires hospitalization to prevent death.
