The Facts
Gastroenteritis literally means inflammation of the gastrointestinal
tract. Viral gastroenteritis is also called "stomach flu." It's
extremely common, especially in children, and is highly contagious. Bacterial
gastroenteritis is also known as food poisoning and is caused by food that has
been prepared or stored improperly.
Causes
Viruses such as the Norwalk virus cause gastroenteritis. Besides
the Norwalk virus, two other viruses are also common causes of gastroenteritis
in North America: the Rotavirus and the Adenovirus, which both
tend to cause disease in infants. They are spread by contaminated feces. From
the feces, viruses find their way into food or water or onto insects or people
who later touch and contaminate food (fecal-oral transmission). Unfortunately,
these viruses are tough enough to beat modern sanitation practices.
Norwalk virus is the typical form of gastroenteritis in adults and older
children. It can occur at any time of year. The Norwalk virus is spread
by the fecal-oral route.
Rotavirus mostly affects infants aged three to 15 months. American
records show that an epidemic wave of rotavirus sweeps across the country each
year, starting in the Southwest in November and ending in the Northeast in March.
Adenovirus is the second most common cause of gastroenteritis in children
under two years of age. It occurs at any time of year.
For infants, diapers are a major source of infection. Germs from the feces
can get on both the baby's and the parent's hands.
Viruses cause disease by infecting or irritating cells within the wall of the
small intestine. This causes fluids, minerals, and salts to flush into the intestines,
exiting as diarrhea.
Food poisoning results when a person eats food that has grown bacteria that
can cause gastroenteritis. The symptoms of food poisoning are caused either
by the bacteria themselves or by the byproducts (toxins) they produce. Symptoms
of food poisoning can begin within a few hours or a few days, depending on whether
the bacteria or the toxin causes the problem.
