Norovirus Clinical Presentation

Updated: Oct 20, 2015
  • Author: Zartash Zafar Khan, MD, FACP; Chief Editor: Mark R Wallace, MD, FACP, FIDSA  more...
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Symptomatic gastroenteritis typically develops 24-48 hours after ingestion of contaminated food or water or after contact with an infected individual. Each episode is short-lived, lasting only 24-72 hours. The onset can be abrupt or gradual.

Symptoms include the following:

  • Nausea and vomiting (profuse, nonbloody, nonbilious)
  • Watery diarrhea (nonbloody)
  • Abdominal cramps
  • Headaches
  • Low-grade fever is common (but temperatures may be higher as well)
  • Myalgias and malaise


Vital signs include low-grade fever, tachycardia, and possible hypotension with volume depletion.

Abdominal examination reveals the absence of focal tenderness and peritoneal signs.



Vectors for norovirus infection include the following:

  • Water sources include both potable water and lake or swimming pool water (when ingested); noroviruses are relatively resistant to inactivation by chlorine.
  • Food sources include shellfish (eg, oysters, clams), salads, cake frosting, and meats. Spread can occur through undercooked contaminated foods or improper hand washing by an infected food handler.
  • Body fluid sources include vomitus and feces from infected individuals. Maximal viral shedding occurs during the first 48 hours of illness; however, viruses can be detected in stool up to 3 weeks after illness resolves. [20]