Norovirus vs Rotavirus
How to tell Norovirus and Rotavirus apart when a board question makes them look alike.
Norovirus is abrupt outbreak vomiting in all ages; rotavirus is severe infant watery diarrhea with segmented dsRNA and vaccine prevention.
Side by side
Norovirus causes abrupt vomiting and watery diarrhea outbreaks in all ages, especially cruise ships, schools, nursing homes, and close-contact settings.
Rotavirus causes severe watery diarrhea in infants and young children, with segmented double-stranded RNA and vaccine prevention.
Norovirus is a nonenveloped positive-sense RNA calicivirus with low infectious dose and environmental stability.
Rotavirus is a nonenveloped segmented double-stranded RNA reovirus whose NSP4 enterotoxin contributes to secretory diarrhea.
Outbreak clustering, rapid onset vomiting, short incubation, and PCR testing support norovirus.
Infant diarrhea, winter seasonality, antigen testing, segmented dsRNA, and lack of vaccination support rotavirus.
The trap
Both cause watery viral gastroenteritis, so age group, outbreak setting, vomiting prominence, and genome separate them.
The repair move
For viral gastroenteritis, use age and outbreak context before memorizing the virus name.
Try a free question
CoreA 6-day-long cruise has 220 passengers and crew developing abrupt vomiting, watery non-bloody diarrhea, and low-grade fever within 24-48 hours of each other. Symptoms last 2-3 days. Ages range from 8 to 78. Stool PCR is positive for a single-stranded positive-sense RNA virus. Which organism is most likely?
Show answer and explanation
Answer: A. Norovirus. Norovirus is the leading cause of nonbacterial gastroenteritis outbreaks in adults, with rapid onset vomiting, short duration, and characteristic spread in closed environments (cruise ships, schools, nursing homes).
Why the other choices are tempting
- B. Rotavirus causes severe watery diarrhea predominantly in unvaccinated infants and young children; adult outbreaks are uncommon.
- C. Vibrio cholerae causes profuse rice-water diarrhea with hypovolemic shock, typically after consumption of contaminated water in endemic regions.
- D. Giardia lamblia causes chronic foul-smelling steatorrhea after freshwater or backcountry water exposure, not abrupt outbreak vomiting.
- E. Enterotoxigenic E. coli causes traveler's diarrhea (watery non-bloody) but is associated with travel rather than closed-environment outbreaks.
Flashcards
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What setting supports norovirus?
Cruise ships, nursing homes, schools, and shared-meal outbreaks support norovirus.
What symptom is especially prominent in norovirus?
Abrupt vomiting is especially prominent in norovirus outbreaks.
Quick answers
What is the fastest way to tell Norovirus from Rotavirus?
Norovirus is abrupt outbreak vomiting in all ages; rotavirus is severe infant watery diarrhea with segmented dsRNA and vaccine prevention.
What is the key clue for Norovirus?
Norovirus causes abrupt vomiting and watery diarrhea outbreaks in all ages, especially cruise ships, schools, nursing homes, and close-contact settings.
What is the key clue for Rotavirus?
Rotavirus causes severe watery diarrhea in infants and young children, with segmented double-stranded RNA and vaccine prevention.
What is the common trap with Norovirus vs Rotavirus?
Both cause watery viral gastroenteritis, so age group, outbreak setting, vomiting prominence, and genome separate them.