Symptoms & Risks of Norovirus Infection
Norovirus causes a relatively short, intense illness characterized by nausea, vomiting, diarrhea and abdominal cramping.
Norovirus illness usually develops 24 to 48 hours after ingestion of contaminated food or water. [5, 16, 33] Symptoms typically last a relatively short amount of time, approximately 24 to 48 hours. [5, 25]
Symptoms of norovirus include nausea, vomiting, diarrhea, and abdominal pain. Headache and low-grade fever may also accompany this illness. [5, 25, 33] People infected with norovirus usually recover in two to three days without serious or long-term health effects. [5, 25]
Although symptoms usually only last one to two days in healthy individuals, norovirus infection can become quite serious in children, the elderly, and immune-compromised individuals. [10, 18, 33] In some cases, severe dehydration, malnutrition, and even death can result from norovirus infection, especially among children and among older and immune-compromised adults in hospitals and nursing homes. [25, 30] In England and Wales, 20% of those over the age of 65 die due to infectious intestinal illness other than Clostridium difficile.  Recently, there have been reports of some long-term effects associated with norovirus, including necrotizing entercolitis, chronic diarrhea, and post-infectious irritable bowel syndrome, but more data is needed to support these claims.