When a person becomes infected with a norovirus, the virus begins to multiply within the small intestine. After approximately 1 to 2 days, norovirus gastroenteritis symptoms can begin. This period between the norovirus transmission and the start of norovirus gastroenteritis symptoms is the "norovirus gastroenteritis incubation period." In some cases, the norovirus gastroenteritis incubation period can be as short as 12 hours.
(Click Norovirus Incubation Period for more information.)
Not all people who are infected with a norovirus will develop norovirus gastroenteritis symptoms. If norovirus symptoms do occur, the illness begins suddenly. Common norovirus gastroenteritis symptoms include:
- Watery diarrhea
- Some stomach cramping
Less common norovirus symptoms can include:
- Low-grade fever
- Muscle aches
- General sense of tiredness.
(Click Norovirus Symptoms for more information.)
In order to make a norovirus gastroenteritis diagnosis, the doctor will ask a number of questions about a person's medical history and will likely perform a physical exam, looking for signs and symptoms of norovirus gastroenteritis.
In most cases, based on the medical history and physical exam, the doctor will make a diagnosis of viral gastroenteritis (also known as the stomach flu), but will not be able to say specifically whether a norovirus infection is causing the gastroenteritis symptoms. This is because there is no routine lab test to detect norovirus.
(Click Norovirus Diagnosis for more information.)