Norwalk virus is considered to be a common cause of community-wide outbreaks of gastroenteritis. It is estimated that 30-40% of outbreaks of infectious diarrhea in the U.S. are due to viral gastroenteritis. Viral gastroenteritis can be caused by many different viruses; however, the most common viruses are of the rotavirus and Norwalk virus strain.

The Norwalk viruses appear more frequently in institutional outbreaks and are common in school-age children. Most infections are self-limiting and resolve without treatment. Dehydration is a rare complication and is treated with fluids. (1)

Chimpanzees fail to succumb to any illness related to infection with the virus as indicated in the abstract below. This research was conducted on “juvenile chimpanzees” (typically two years old or younger).

From the abstract:

The Norwalk-like human caliciviruses are the major cause of nonbacterial epidemic gastroenteritis that occurs in family, school, institutional, or community-wide outbreaks affecting adults and school-aged children.…A Norwalk virus-containing stool filtrate was administered orally or intravenously to two juvenile chimpanzees in order to establish an infectious dose titer. The first dose was administered at a 10-5 dilution. A pre-challenge serum sample was collected and then another serum sample was collected approximately 2 weeks later. The animals did not develop illness and also failed to demonstrate a serologic response to Norwalk virus. Stool samples were collected immediately prior to challenge and then daily for approximately 10 days. Each sample from the two chimpanzees was analyzed by RT-PCR for evidence of virus shedding and Norwalk virus was not detected. The titration continued at sequentially lower ten-fold dilutions until the stool filtrate was administered orally to one of the chimpanzees without dilution. At the completion of the study, there was no evidence for Norwalk virus replication in either chimpanzee. These observations were in contrast to earlier work in LID, in which adult chimpanzees showed evidence for infection after challenge with an aliquot of the same filtrate containing Norwalk virus. The reason for the failure in this experiment to infect juvenile chimpanzees is under investigation, and could yield important insight into possible age- or immunity-related host factors related to susceptibility to infection.

Last update: 1/10/06

Sources

(1) Medline Plus, a service of the NIH and the National Library of Medicine, web retrieved on October 18, 2005 at http://www.nlm.nih.gov/medlineplus/ency/article/000252.htm

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