What is the diagnosis and treatment for Norovirus (Norwalk virus) induced gastroenteritis?

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Last updated: February 25, 2025View editorial policy

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From the Guidelines

Norovirus gastroenteritis is a highly contagious viral infection that requires prompt supportive care to prevent dehydration and other complications, with a focus on maintaining hydration, rest, and a bland diet, as well as preventing further transmission through good hand hygiene and disinfection of contaminated surfaces. The primary approach to treatment is maintaining hydration through oral rehydration solutions like Pedialyte or homemade solutions (1 teaspoon salt, 8 teaspoons sugar in 1 liter of water) 1. Adults can take over-the-counter medications like loperamide (Imodium) for diarrhea and acetaminophen (Tylenol) for fever and pain, but these should be avoided in children without medical advice 1. Rest is essential, and a bland diet (bananas, rice, applesauce, toast) can help during recovery. Most cases resolve within 1-3 days without specific treatment.

Key Considerations

  • Prevention is crucial due to high contagiousness - wash hands thoroughly with soap and water for 20 seconds, disinfect contaminated surfaces with bleach-based cleaners, and avoid preparing food for others while sick and for 48 hours after symptoms resolve 1.
  • The virus spreads through contaminated food, water, surfaces, and direct contact with infected individuals, with symptoms typically appearing 12-48 hours after exposure and including vomiting, watery diarrhea, abdominal cramps, and sometimes fever 1.
  • Norovirus-associated deaths have been reported among elderly persons and in the context of outbreaks in long-term–care facilities, highlighting the importance of prompt and effective management 1.

Diagnosis and Reporting

  • Collect whole stool specimens from at least five persons during the acute phase of illness (≤72 hours from onset) for diagnosis by TaqMan-based real-time reverse transcription-PCR (RT-qPCR) 1.
  • Report all outbreaks of acute gastroenteritis to state and local health departments, in accordance with local regulations, and to CDC via the National Outbreak Reporting System (NORS) 1.

From the Research

Diagnosis of Norovirus Induced Gastroenteritis

  • Norovirus is generally an acute infection causing symptoms such as diarrhea, nausea, and vomiting lasting for 24-48 hours 2
  • The degree of dehydration can be judged from weight loss and other clinical findings 3
  • The four-item Clinical Dehydration Scale can be used to determine severity of dehydration based on physical examination findings 4

Treatment of Norovirus Induced Gastroenteritis

  • Oral rehydration therapy is the mainstay of treatment for mild dehydration and is as effective as intravenous rehydration for preventing hospitalization and return to the emergency department 3, 4
  • Oral rehydration solutions are recommended for moderate dehydration 4
  • Ondansetron may be prescribed if needed to prevent vomiting and improve tolerance of oral rehydration solutions 4
  • Hospitalization and intravenous fluids are recommended for children who do not respond to oral rehydration therapy plus an antiemetic and patients with severe dehydration 4
  • For immunocompromised patients, several treatment strategies have been suggested in case reports: nitazoxanide, ribavirin and enterally administered immunoglobulin with varying results 2
  • Favipiravir is also suggested but not tested on humans, highlighting the need for further research 2
  • Gatorade and a New Oral Rehydration Solution (N-ORS) seem to be as effective as Pedialyte in correcting dehydration and in improving bowel symptoms 5

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

[Not Available].

Ugeskrift for laeger, 2023

Research

Acute Infectious Gastroenteritis in Infancy and Childhood.

Deutsches Arzteblatt international, 2020

Research

Gastroenteritis in Children.

American family physician, 2019

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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