Norovirus is a highly contagious virus that affects the digestive system, leading to vomiting and diarrhea. Transmission occurs through direct contact with the feces or vomit of infected individuals, or by consuming contaminated food and water. This virus can be resistant to disinfectants and varying temperatures.

Norovirus infections can cause prolonged symptoms, leading to weakness and exhaustion. Inadequate hygiene practices and unreliable water sources significantly increase the spread of the virus. The disease poses a higher risk of severe progression particularly in the elderly, young children, and individuals with weakened immune systems. Contaminated foods such as shellfish, frozen foods, and insufficiently washed greens are also important sources of transmission.

The main transmission routes and risk factors for norovirus include:
* Close contact with infected individuals (especially via the fecal-oral route)
* Touching the mouth, nose, or eyes after touching contaminated surfaces
* Consuming virus-contaminated food and beverages (e.g., undercooked shellfish, unwashed fruits and vegetables)
* Communal living areas or recreational water sources with inadequate hygiene conditions
* A weak immune system (as a risk factor that increases the severity of the infection)