The norovirus – way more common than you probably think


in Geek stuff, Science

Lamplight and sunset

When people say that they are sick with ‘the flu,’ they often mean they have gastroenteritis. Influenza is caused by viruses in the family Orthomyxoviridae and is the stuff of flu vaccines and avian flu worries. Influenza usually often presents with fever, sore throat, muscle pains, severe headache, coughing, weakness and general discomfort. Gastroenteritis is defined as inflammation of the gastrointestinal tract, involving both the stomach and the small intestine. While it can be caused by bacteria including salmonella and E. Coli, gastroenteritis is usually caused by norovirus or rotavirus. In North America, only the common cold (usually caused by a picornavirus or coronavirus) is a more frequently occurring illness.

Norovirus is of particular interest, since it causes about 50% of all food-related cases of gastroenteritis. In total, it causes about 90% of non-bacterial gastroenteritis worldwide. Norovirus is transmitted either directly from person-to-person or through the faecal contamination of food or water. It is highly susceptible to bleach, though more resistant to alcohol and soap. Susceptibility to the virus is genetically linked. About 29% of the population have two recessive copies of the (1,2)fucosyltransferase gene, which means they don’t form a ligand required by the virus to bond. Lucky people. People with at least one dominant copy of the gene only get a brief period of partial immunity after the fight off the virus. Your best bet is to wash your hands often, avoid salads and shellfish cooked in places with poor hygienic standards, and avoid exposing yourself to people who are already infected.

{ 5 comments… read them below or add one }

Litty February 12, 2008 at 9:54 am

Damn you dominant (1,2)fucosyltransferase gene! Damn you!

. February 12, 2008 at 10:26 am

Noroviruses – Fact Sheet

Noroviruses are a group of viruses that cause gastroenteritis in people. These viruses are part of a family called caliciviruses. While animals do carry other kinds of caliciviruses, they are not believed to carry noroviruses. The term norovirus was approved as the official name for this group of viruses in 2002. Previously, they were called Norwalk-like viruses. Noroviruses are commonly found throughout North America and are very infectious. Noroviruses can survive on practically any surface including door handles, sinks, railings and glassware. They occur throughout the year but are more common in winter and affect all age groups…

The virus is able to survive relatively high levels of chlorine and varying temperatures and can survive on hard surfaces in the environment for up to 12 hours. It has been found to survive on contaminated carpet for up to 12 days. Noroviruses are easily transmitted in environments where people are in close contact, including schools, day-care centres, long-term care facilities, healthcare facilities and cruise ships.

Dipl.-Ing. Wilfried Soddemann February 13, 2008 at 3:41 am

Norovirus infections:
Triggered off by drinking water in the run-up to secondary spread from human to human

Norovirus infections are triggered off fecal-oral by food or water. They occur strong seasonal in the cold dependent on environmental temperatures [water, soil, drinking water pipes]. The cold is the main factor to conserve virulent noroviruses in water. Food temperature does not change. There must be an abiotic vehicel like drinking water that changes its temperature in the cold. So norovirus infections mainly are triggered off by drinking water in the run-up to secondary spread from human to human.
The performance to eliminate viruses from the drinking water processing plants regularly does not meet the requirements of the WHO and the USA. Conventional disinfection procedures are poor, because microorganisms in the water are not in suspension, but embedded in particles. Conventional disinfection procedures (chlorine, ozone) are less effective in the cold. Even ground water used for drinking water is not free from viruses.

Links to the specialized literature:
Bundesgesundheitsblatt – Gesundheitsforschung – Gesundheitsschutz
Volume 50, Number 3 / März 2007
K. Botzenhart
Viruses in drinking water
Emerg Infect Dis [serial on the Internet]. 2005 Nov.
Maunula L, Miettinen IT, von Bonsdorff C-H.
Norovirus outbreaks from drinking water.

. February 25, 2008 at 12:00 pm

Fix the Flu Shot

Why can’t they cram all the strains of influenza into a single dose?
By Michelle Tsai

The flu shot protects against only 40 percent of this year’s viruses, the Centers for Disease Control said last week. On Thursday, the FDA decided to replace all three of the vaccine’s influenza strains for next winter. Wait, why can’t the scientists put every strain there is into the vaccine?

. June 4, 2009 at 5:30 pm

Take a Bite Out of Food-Borne Illnesses This Summer
3 surprising facts beyond the familiar headlines.
By Maggie Koerth-Baker for MSN Health & Fitness

Summertime is prime time for food-borne illness. Each year, some 76 million Americans get sick because of something they ate, and experts say cases peak during warm months. Education is one of the best ways to fight back against the bugs; this year, arm yourself with some high-caliber facts.

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