What is norovirus? How to protect yourself from the highly contagious stomach bug

Health & Fitness
13 May 2026 • 10:10 PM MYT
The Independent
The Independent

The world’s most free-thinking newspaper

What is norovirus? How to protect yourself from the highly contagious stomach bug

  • Norovirus is a highly contagious virus that causes acute gastroenteritis, characterized by severe vomiting and diarrhea, and is distinct from the influenza virus despite sometimes being called the stomach flu, according to the CDC.
  • Symptoms typically appear 12 to 48 hours after exposure and can be extremely debilitating, involving frequent vomiting and diarrhea, though most individuals recover within one to three days.
  • The illness carries a significant risk of dehydration due to rapid fluid loss, especially in vulnerable populations such as young children, older adults, and people with other underlying health conditions.
  • Anyone can contract norovirus, with outbreaks affecting people of all ages, and an individual's genetic predisposition can influence their likelihood of infection.
  • Raw oysters and other filter-feeding shellfish are common sources of norovirus, and while anyone consuming them is at risk, children under five, older adults, and those with weakened immune systems are more prone to developing severe infections.

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