How long am I contagious when I have the stomach flu
"It depends on which virus is causing your stomach flu (viral gastroenteritis). The contagious period – the time during which a sick person can give the illness to others – is slightly different for each virus," explains Douglas Marquess, MD, who is board certified in internal medicine at Baptist Medical Associates.
Norovirus is the most common cause of viral gastroenteritis in adults. Symptoms appear within one to three days of exposure.
"With norovirus, you’re contagious from the moment you begin to feel ill. Although you typically feel better after a day or two, you’re contagious for at least three days after you’ve recovered," Dr. Marquess says.
Some people may be contagious for up to two weeks after recovery. Also, children are often contagious for a longer period than are adults.
Rotavirus is the leading cause of viral gastroenteritis in infants and young children. Symptoms of rotavirus appear one to two days after exposure. But you’re contagious even before you develop symptoms, and you typically remain contagious for two weeks after you've recovered.
For these reasons, it’s important to wash your hands frequently and thoroughly. The viruses that cause gastroenteritis are spread through close contact with infected persons, such as by sharing food or eating utensils.
"Washing your hands is the most effective way to stop the spread of these viruses to others," Dr. Marquess adds.