How long does norovirus last?

Duration of Norovirus Illness

In otherwise healthy individuals, norovirus symptoms typically last 1-3 days, though viral shedding continues for an average of 4 weeks after infection. 1

Symptom Duration by Population

Immunocompetent Adults and Children

• Acute symptoms resolve within 12-72 hours in most immunocompetent hosts, with the illness being self-limiting 1
• The typical course includes 1-3 days of vomiting, diarrhea, nausea, and abdominal cramps 1
• Some patients report symptom duration of half a day to 5 days 2

High-Risk Populations with Prolonged Illness

Prolonged courses lasting 4-6 days occur particularly in:

• Young children 1, 3
• Elderly persons 1, 3
• Hospitalized patients 1

Immunocompromised Patients

• Severely immunocompromised patients can experience chronic norovirus gastroenteritis lasting several years, with continuous viral shedding, villous atrophy, and severe malnutrition 4
• Cancer patients with impaired cellular immunity (e.g., post-allogeneic stem cell transplant) are predisposed to prolonged diarrhea and viral shedding 1
• A mortality rate of up to 25% has been reported in allogeneic stem cell transplant patients 1

Viral Shedding vs. Symptom Duration

Critical distinction: While symptoms resolve quickly, viral shedding persists much longer:

• Peak viral shedding occurs 2-5 days after infection, with approximately 100 billion viral copies per gram of feces 1
• Viral shedding continues for an average of 4 weeks following infection 1, 3
• Up to 30% of infections are asymptomatic, yet these individuals still shed virus at lower titers 1
• The exact duration of contagiousness remains unknown due to lack of cell culture systems to determine viral infectivity 1

Clinical Management Implications

When to Seek Medical Attention

• Approximately 10% of norovirus patients require medical attention for dehydration management with oral or intravenous fluids 1, 3
• Symptoms persisting beyond 1 week warrant immediate evaluation for alternative diagnoses, dehydration assessment, and consideration of prolonged illness in vulnerable populations 3

Isolation Precautions

• Maintain isolation until 24-48 hours after complete symptom resolution 3
• Infectivity can last for as long as 2 days after symptom resolution 1
• Do not require negative stool results prior to returning to work, as viral shedding continues long after contagiousness ends 3

Common Pitfalls

Avoid these mistakes:

• Do not assume patients are no longer contagious once symptoms resolve—maintain precautions for 24-48 hours post-resolution 3
• Do not rely on viral shedding detection (up to 4 weeks) as an indicator of ongoing contagiousness 1, 3
• Recognize that elderly patients may report constitutional symptoms persisting for several weeks despite resolution of acute gastroenteritis 1