1. Norwalk Virus Scott VasporyCraig Pritch October 4, 2005

2.  History of the virus  Morphology  Symptoms  Transmission  Prevention Norwalk Virus

3. Introduction to the Norwalk Virus  Norwalk – genus name for original Norwalk virus and other Norwalk-like viruses. Family Calicivirus.  Calicivirae found worldwide, infecting humans, primates, and cattle, among others.  Increasingly being recognized as leading cause of food borne illness.

4. History  Virus first identified in Norwalk, Ohio, 1973.  Noted to commonly be a problem on cruise ships.  Associated with contaminated food or water supplies.

5. Physiology  (+) ssRNA, nonenveloped virus.  ~ 7.4 - 8.3 kb  Many different strains.

6. Morphology  Nonenveloped capsid/nucleocapsid.  Icosahedral, 35-39 nm diameter Picture: Norwalk virus, left and middle. Unspecified Calicivirus, right.

7. Genome Organization ORF1 – polyprotein – similar to helicase, RNA polymerase of polio and RNA viruses ORF2 – capsid protein ORF3 – codes for protein of unknown function

8. Infection  Noroviruses found in stool and vomit of infected.  Very contagious – infection via eating contaminated food, contact with sick individual or contaminated surfaces.

9. Symptoms  Acute gastroenteritis.  Illness begins suddenly, from 12-48 hours after ingestion. Brief illness period.  Very young, elderly, and those with weakened immune systems may experience more severe symptoms.  Infectiousness may last up to 2 weeks, no evidence of long-term carriers.

10. Diagnosis  Electron Microscope  RT-PCR  ELISA  Calicivirus is not easily studied. No efficient techniques have been developed to culture it in a lab setting.

11. Prevention

12. References Büchen-Osmond, C. (Ed), (2003). 00.012. Caliciviridae. In: ICTVdB - The Universal Virus Database, version 3. ICTVdB Management, Columbia University, New York, NY, USA. CDC. accessed September 29, 2005. Norovirus. http://www.cdc.gov/ncidod/dvrd/revb/gastro/norovirus-qa.htm Directors of Health Promotion and Education. Accessed September 29, 2005. Norwalk Virus Infection. http://www.astdhpphe.org/infect/norwalk.html Microbiology Department, Mount Sinai Hospital. Accessed October 2, 2005. Norwalk and Noroviruses. http://microbiology.mtsinai.on.ca/bug/norwalk/nor-bug.shtml http://microbiology.mtsinai.on.ca/bug/norwalk/nor-bug.shtml

13. Scott Vaspory svaspory@eden.rutgers.edu Craig Pritch hsteinway@gmail.com