Some risk factors for viral gastroenteritis, also known as stomach flu, include age, immune-status and close proximity to many other people, according to Mayo Clinic. Gastroenteritis is spread through person-to-person contact or by ingesting contaminated water or food.
It is possible for anyone to get gastroenteritis, but recovery for most people is short and without major complications. However, for people with compromised immune systems, such as infants or older adults, gastroenteritis can be deadly, explains Mayo Clinic. Others with weakened immune systems who are at increased risk include people with HIV/AIDS and chemotherapy patients. Those who are constantly in close proximity to others, such as schoolchildren or college dorm residents, are also at risk because of the potential for increased exposure to the virus.