Individuals can contract the stomach flu virus by coming in contact with someone infected by the virus or consuming contaminated foods or beverages, as stated by WebMD. The illness can affect both the stomach and intestines.
An individual can contract a stomach flu virus while in close contact with an infected person, such as when sharing eating utensils or food, as confirmed by Mayo Clinic. An individual can also contract the virus by touching a contaminated surface or item. Washing hands with soap and water, carefully rinsing fresh produce, disinfecting contaminated surfaces with bleach and avoiding cooking while infected help prevent the spread of the illness, according to the Centers for Disease Control and Prevention.
Individuals infected by norovirus, the most common cause of the viral stomach flu in children and adults, become contagious the moment they begin to experience symptoms, according to Mayo Clinic. They normally remain contagious for up to three days after recovering, but some individuals may remain contagious for several weeks. In cases of rotavirus, the most common viral stomach flu in babies and young children, infected individuals are contagious before symptoms appear and remain so for up to two weeks after recovery. Oral vaccines are available to protect children from rotavirus.