Gastroenteritis, commonly known as a “stomach virus,” is an inflammation of the stomach and intestines, typically resulting from a viral infection. Despite its common name “stomach flu,” it differs from influenza, which primarily affects the respiratory system. Symptoms often include sudden, watery diarrhea, nausea, vomiting, abdominal cramps, mild fever, loss of appetite, or body aches. These usually emerge within 12 to 72 hours after exposure and typically subside within a week.
How Stomach Viruses Pass Between People
Stomach viruses, such as norovirus, are highly contagious. The main way these viruses are transmitted is through the fecal-oral route, meaning microscopic particles of feces or vomit from an infected individual are unintentionally ingested by another person. Only a small number of viral particles are needed to cause an infection. Infected individuals shed billions of these particles in their stool and vomit, often even before symptoms appear and for days or weeks after recovery.
Direct person-to-person contact is a common transmission pathway. This often occurs when caring for sick family members, such as helping with hygiene or changing diapers, leading to transfer of the virus from contaminated hands to one’s mouth. Close proximity to a vomiting person can also lead to infection, as tiny aerosolized droplets containing the virus can spread through the air and be inhaled or land on surfaces.
Indirect contact, through contaminated surfaces and objects, also plays a role in viral spread. Viruses like norovirus are remarkably robust, capable of surviving on hard surfaces such as doorknobs, light switches, and countertops for up to two weeks. When an uninfected person touches these contaminated surfaces and then touches their mouth, nose, or eyes, the virus can enter their body and initiate an infection. This resistance to typical environmental conditions contributes to their widespread transmission.
Contaminated food and water are another significant route for transmission. Food can become tainted if an infected person prepares it without thorough handwashing, allowing viral particles to transfer directly. Additionally, food can be contaminated if it comes into contact with surfaces that have viral particles on them. Water sources, including wells or recreational water, can become contaminated through sewage leaks or infected individuals using the water. Examples include produce washed with contaminated water or shellfish harvested from tainted waters.
Stopping the Spread of Stomach Viruses
Preventing stomach virus spread relies on diligent hygiene practices. Thorough handwashing is the most effective measure. Hands should be washed frequently with soap and water for at least 20 seconds, especially after using the restroom, before eating or preparing food, and after caring for someone who is sick. Hand sanitizers containing alcohol are not as effective against these viruses as soap and water, though they can be used in addition to washing.
Cleaning and disinfecting surfaces are important, especially when someone in the household is ill. High-touch areas like doorknobs, light switches, bathroom fixtures, and remote controls should be cleaned regularly. A bleach solution or an EPA-registered disinfectant effective against norovirus is recommended for disinfection. Surfaces should be cleaned first to remove visible soil, then disinfected, allowing the solution to remain on the surface for several minutes before wiping clean.
Isolating sick individuals helps contain the virus. Those with symptoms should remain home from work or school until at least 48 hours after their symptoms have completely resolved. Avoid sharing personal items such as towels, eating utensils, and bedding with sick individuals. Contaminated clothing or linens should be washed separately using hot water and detergent, and machine dried at the highest heat setting.
Practicing safe food handling reduces transmission risk. Wash fruits and vegetables thoroughly before consumption. Meats and shellfish should be cooked to their proper internal temperatures, as some viruses can survive high heat. Avoid cross-contamination between raw and ready-to-eat foods. Sick individuals should not prepare food for others.