What is the typical duration of a viral illness causing vomiting?

Duration of Viral Illness Causing Vomiting

The typical duration of a viral illness causing vomiting is generally a self-limited illness of a few days' duration, with most cases resolving within 12-72 hours for norovirus and 3-8 days for rotavirus. 1

Common Viral Causes and Their Duration

Norovirus

• Incubation period of 12-48 hours followed by vomiting, diarrhea, abdominal pain, myalgia and low-grade fever 1
• Symptoms typically last for 12-72 hours in immunocompetent hosts 1
• Viral shedding may continue for up to 3 weeks after symptoms resolve 1
• In a study of Norwalk virus infection, bismuth subsalicylate reduced duration from 27 to 20 hours 1

Rotavirus

• Incubation period of 1-3 days 1
• Illness begins with acute onset of fever and vomiting followed by watery diarrhea 24-48 hours later 1
• Symptoms generally persist for 3-8 days 1
• Vomiting occurs in 80-90% of infected children but is usually brief, lasting 24 hours or less 1
• Viral excretion continues for 8-14 days 1
• May cause mild lactose intolerance for 10-14 days after infection 1

Clinical Characteristics by Age Group

Children

• Vomiting is more prominent in children with viral gastroenteritis, occurring in up to 90% of cases 1, 2
• Rotavirus disease tends to be most severe in children between 3-24 months of age 1
• Children typically have 10-20 bowel movements per day during the acute illness 1
• Fever occurs in up to half of infected children and is usually low-grade 1

Adults

• Adults usually have asymptomatic or mild disease due to immunity from previous exposure 1
• In outbreaks among adults (typically Norwalk-like viruses), symptoms include nausea (79%), abdominal cramps (71%), vomiting (69%), and diarrhea (66%) 1
• Average duration of illness in adults is 12-60 hours 1

Special Populations

Immunocompromised Patients

• May experience prolonged courses of diarrhea and viral shedding 1
• In severely immunocompromised patients (e.g., transplant recipients), norovirus infection can persist for several years 3
• Cancer patients with impaired cellular immunity are at increased risk for prolonged symptoms 1
• Mortality rates up to 25% have been reported in allogeneic stem cell transplant patients with norovirus gastroenteritis 1

Elderly

• The elderly may experience more severe symptoms and complications due to waning immunity 1
• Maintaining good hydration is particularly important in the elderly, especially those receiving diuretic medications 1

Management Considerations

• The main risk during viral gastroenteritis is dehydration and electrolyte imbalance 1
• Vomiting may continue during the first 1-2 hours of oral rehydration therapy but will usually diminish or stop 4
• Even if vomiting occurs during rehydration attempts, most fluid administered is actually retained 4
• For severe dehydration, rapid IV rehydration (20-30 mL/kg over 1-2 hours) can correct dehydration and resolve vomiting in many children 5
• Antiemetics should generally be avoided as they may cause drowsiness that interferes with oral rehydration 4

When to Seek Medical Care

• Seek medical attention if vomiting persists beyond the expected duration (>72 hours for norovirus, >8 days for rotavirus) 1
• Signs of severe dehydration require immediate medical evaluation 1, 5
• Regular review in the early phases of undifferentiated vomiting illness is important to ensure more serious conditions are not overlooked 2

Remember that viral gastroenteritis is generally self-limited, and the focus of management should be on maintaining hydration until the illness resolves naturally 1.