Stomach Virus

There is no "stomach virus" per se. Viruses that cause the condition most commonly known as "stomach flu" actually affect the small intestine. Symptoms of these infections include vomiting, diarrhea, and sometimes body aches. Anyone can become infected, although infants and children, the elderly, and people with weakened immune systems may have a more severe form of the infection. What Is the Stomach Virus? Stomach flu is caused by a virus. There are a number of different viruses that can cause stomach flu, but the so-called "stomach virus" does not actually affect the stomach at all. Viruses that cause stomach flu affect the small intestine. Furthermore, these stomach flu viruses are not actually flu viruses. The flu virus is the influenza virus. Influenza virus does not cause stomach flu symptoms. Regardless of the inaccuracies of the terms "stomach flu" and "stomach virus," these are the most commonly used terms to describe what healthcare providers call viral gastroenteritis. Specific Facts Regarding the Stomach Virus There are a number of viruses that can cause stomach flu. There are four main types of stomach viruses: * Rotavirus * Caliciviruses * Adenovirus * Astrovirus. Rotavirus Rotavirus is the leading cause of stomach flu among children 3 months to 15 months old and the most common cause of diarrhea in children under the age of 5 years. This type of "stomach virus" causes vomiting and watery diarrhea for 3 to 8 days, along with fever and abdominal pain. This stomach flu virus can also infect adults who are in close contact with infected children, but the symptoms in adults are milder (see Adult Rotavirus). In the United States, rotavirus infections are most common from November to April. Caliciviruses Caliciviruses cause infection in people of all ages. This family of viruses is divided into four types, the noroviruses (see Norovirus) being the most common. It is now thought that at least 50 percent of all foodborne outbreaks of gastroenteritis can be attributed to noroviruses. Norwalk virus is a type of norovirus. People infected with one of these "stomach viruses" may develop vomiting and diarrhea, fatigue, headache, and sometimes muscle aches. Norovirus symptoms appear within 1 to 3 days of exposure. Adenovirus Adenovirus infections occur mainly in children under 2 years of age. Of the 49 types of adenoviruses, one strain affects the gastrointestinal tract, causing vomiting and diarrhea. Symptoms from this "stomach virus" typically appear 1 week after exposure. Adenovirus infections occur year-round. Astrovirus Astrovirus infects primarily infants, young children, and the elderly. This type of "stomach virus" is most active during the winter months. Vomiting and diarrhea appear within 1 to 3 days of exposure.