Stomach Flu Incubation Period
In people with stomach flu, the incubation period may range from 4 hours to 1 to 2 days, depending on the type of virus that is causing the infection. Furthermore, some people are contagious during the stomach flu incubation period and others are not -- again, it depends on the type of virus that is causing the infection.
When a person becomes infected with stomach flu, the virus begins to multiply within the small intestine. After approximately 1 to 2 days, depending on the virus, stomach flu symptoms can appear. This period between the stomach flu transmission and the start of symptoms is the "stomach flu incubation period." In some cases, the stomach flu incubation period can be as short as 4 hours.
Whether or not a person is contagious during the stomach flu incubation period will depend on which stomach flu virus the person is infected with. For example, with a rotavirus infection, the person is contagious during the stomach flu incubation period. This person is also contagious while experiencing stomach flu symptoms. Once the diarrhea has ended, a person with rotavirus gastroenteritis is no longer contagious.
In the case of a norovirus infection (including Norwalk virus), a person is not usually contagious during the stomach flu incubation period. People infected with norovirus gastroenteritis are usually contagious from the moment they begin feeling ill to at least 3 days after recovery. Some people may be contagious for as long as 2 weeks after recovery.