Which viruses most commonly cause acute gastroenteritis presenting with nausea, vomiting, and diarrhea?

Most Common Viruses Causing Nausea, Vomiting, and Diarrhea

Norovirus is the most common viral cause of acute gastroenteritis across all age groups in the United States, accounting for 58% of all gastroenteritis illnesses and causing an estimated 21 million cases annually. 1, 2

Primary Viral Pathogens by Age Group

Adults and All Ages

• Norovirus is the predominant cause of gastroenteritis outbreaks among adults and is responsible for approximately 50% of all reported gastroenteritis outbreaks worldwide 1, 2
• Norovirus causes acute onset of symptoms after a 12-48 hour incubation period, with nausea, vomiting, non-bloody diarrhea, and abdominal cramps lasting 1-3 days in healthy individuals 1, 3
• The virus is highly contagious, requiring as few as 10 viral particles to cause infection 2

Children Under 5 Years

In the post-rotavirus vaccine era, the hierarchy has shifted:

• Norovirus has replaced rotavirus as the leading cause of acute gastroenteritis in vaccinated children, causing nearly 1 million ambulatory care visits and 14,000 hospitalizations annually 2, 4
• Rotavirus remains the most common cause of severe diarrhea requiring hospitalization among unvaccinated children, with peak incidence at 6 months to 2 years of age 1, 4
• Enteric adenoviruses (serotypes 40 and 41) contribute to 5-20% of hospitalizations for childhood diarrhea, with peak incidence under 2 years of age 4
• Astrovirus accounts for 3-5% of diarrhea-related hospital admissions in children, primarily affecting those under 7 years 1, 4

Clinical Distinction Between Pathogens

Norovirus Characteristics

• Incubation: 12-48 hours 1, 3
• Prominent nausea and vomiting are hallmark features, often more severe than with other viral causes 1
• Duration: typically 12-72 hours in healthy individuals, but 4-6 days in young children, elderly, and hospitalized patients 1, 3
• Non-bloody diarrhea with no fecal leukocytes 1

Rotavirus Characteristics

• Incubation: approximately 2 days 1
• Vomiting for 3 days followed by watery diarrhea for 3-8 days 1
• Fever and abdominal pain occur frequently 1
• Can cause severe dehydration requiring hospitalization in young children 1

Adenovirus and Astrovirus

• Both cause milder, self-limited illness primarily in children under 2 years 1, 4
• Incubation: 24-36 hours for astrovirus 1
• Duration: 1-4 days for astrovirus, slightly longer for adenovirus 1

Important Clinical Pitfalls

Do not assume rotavirus in vaccinated children—norovirus is now the more likely culprit in this population, even during traditional "rotavirus season" (October-April) 2, 4. Commercial rotavirus antigen tests have high false-positive rates in newborns and breastfeeding children, so confirmatory testing should be performed when rotavirus would be unusual (e.g., summer months or in adults) 1.

Norovirus can cause prolonged illness beyond the typical 1-3 day course—up to 4-6 days in vulnerable populations including young children, elderly persons, and hospitalized patients 1, 3. In immunocompromised patients, norovirus can cause chronic diarrhea lasting months to years with mortality rates up to 25% in stem cell transplant recipients 3.

Epidemiologic Context

The burden of viral gastroenteritis has evolved significantly with rotavirus vaccination implementation in 2006-2008, which reduced clinically significant rotavirus disease through both direct protection of vaccinated infants and indirect community protection of unvaccinated individuals 1. This has elevated norovirus to the leading position across all age groups, whereas historically rotavirus dominated pediatric gastroenteritis 1, 2.

Most acute diarrhea episodes in healthy, immunocompetent individuals are self-limited and of viral or unknown etiology, making laboratory investigation generally unwarranted unless there are specific epidemiologic or clinical features suggesting bacterial infection or outbreak situations 1.