A “stomach virus,” medically known as viral gastroenteritis, is an inflammation of the stomach and intestines caused by a viral infection. Symptoms include watery diarrhea, nausea, vomiting, and abdominal cramps, sometimes accompanied by a low-grade fever. While often referred to as “stomach flu,” it is distinct from influenza, which is a respiratory illness. Understanding how these viruses spread is important because they are highly contagious and can affect people of all ages.
The Viral Culprits
Several viruses cause viral gastroenteritis. Norovirus is the most frequent cause of outbreaks and individual cases in both adults and children globally, known for spreading rapidly in confined environments.
Rotavirus is another common cause, particularly affecting infants and young children worldwide. A vaccine is available for rotavirus, significantly reducing severe illness. Other viruses, such as Adenovirus and Astrovirus, also contribute. Adenovirus often affects children under two, while Astrovirus primarily impacts children, older adults, and immunocompromised individuals.
How Stomach Viruses Spread
Viral gastroenteritis primarily spreads through the fecal-oral route, via microscopic particles of an infected person’s stool. This occurs when individuals do not wash hands thoroughly after using the bathroom or changing diapers. Viruses can survive outside the body for extended periods, making transmission easier.
Contaminated food and water are common sources of infection. Food becomes contaminated if prepared by an infected person with poor hand hygiene, or if produce is washed with contaminated water. Untreated or recreational water where an infected person has been can also transmit the virus.
Person-to-person contact also facilitates spread, both directly and indirectly. Direct contact occurs when caring for a sick person. Indirect contact involves touching surfaces or objects contaminated by an infected individual’s vomit or stool. Norovirus, for example, can persist on surfaces for days or weeks, highlighting its easy transmission.
Who is Most Vulnerable
Certain individuals face a higher likelihood of contracting a stomach virus or experiencing more severe symptoms. Young children, especially infants, are vulnerable due to their developing immune systems. Older adults also face increased risk because their immune systems become less efficient with age.
Individuals with weakened immune systems, whether from illness or medications, are more susceptible to severe infections. These groups may experience more prolonged or intense symptoms and are at a higher risk of complications like dehydration.
Crowded environments, such as daycare centers, schools, nursing homes, and cruise ships, are settings where stomach viruses spread rapidly. The close proximity of individuals in these locations increases transmission through person-to-person contact and contaminated surfaces. In these settings, inadequate handwashing also significantly elevates the risk of infection.
Preventing Viral Gastroenteritis
Practicing thorough hand hygiene is among the most effective ways to prevent stomach viruses. This involves washing hands frequently with soap and water for at least 20 seconds, especially after using the restroom, changing diapers, and before preparing or eating food. Alcohol-based hand sanitizers are not always effective against certain viruses like norovirus, which is resistant to alcohol.
Ensuring food safety is another preventive measure. This includes properly cooking foods, washing fruits and vegetables thoroughly, and avoiding cross-contamination between raw and cooked items. If someone in the household is sick, they should avoid preparing food for others for at least 72 hours after symptoms subside.
Regularly cleaning and disinfecting frequently touched surfaces helps reduce viral transmission. Bleach solutions are effective against resilient viruses like norovirus, which can survive on surfaces for up to two weeks. Limiting close contact with individuals who are ill also helps prevent transmission.
Vaccination offers specific protection against certain stomach viruses. The rotavirus vaccine is recommended for infants and protects against severe rotavirus illness and hospitalization. Administered orally in multiple doses, the first dose is typically given before 15 weeks of age, with all doses completed before the infant turns 8 months old.