BarnGoddess said:
I heard on the radio about cases of Norwalk or Norfolk Virus outbreaks. I haven't googled yet but has anyone else heard this?
Norwalk virus is the leading cause of viral gastroenteritis in the U.S.
Norwalk virus causes acute gastroenteritis with nausea, vomiting, fever, and myalgia that lasts 24-48 hours. The virus is transmitted through fecal-oral contact. The Norwalk virus is well established as the chief cause of viral gastroenteritis epidemics. The disease occurs throughout the year without a seasonal predominance.
Norwalk virus was first associated with gastroenteritis in 1972. It was identified by electron microscopy of stool samples that had been saved from a 1968 gastroenteritis epidemic that occurred in Norwalk, Ohio. In a 2-day period, acute gastroenteritis developed in 50% of 232 students or teachers in an elementary school. The virus initially was labeled as a small, round, structured virus, and it was named after the city in which the outbreak occurred.
Information on the molecular characteristics of the virus is limited. It cannot be grown in any cell culture, and no readily available nonhuman animal model becomes ill from the Norwalk virus.
The virus is transmitted through contaminated food, water, or infected contacts. After ingestion, the virus infects the mucosa of the proximal small intestine, damages microvilli, and causes malabsorption of D-xylose, lactose, and fat. Although no histopathological lesions can be found in the stomach mucosa, the virus causes abnormal gastric motility and delayed gastric emptying. It does not invade the colon and, therefore, does not cause fecal leukocytes or hematochezia.
http://www.emedicine.com/med/topic1648.htm