Management of Norovirus GI/GII Gastroenteritis
The management of norovirus gastroenteritis centers on oral rehydration therapy with reduced osmolarity oral rehydration solution (ORS) for mild-to-moderate dehydration, with intravenous fluids reserved for severe dehydration, followed by strict infection control measures including handwashing and isolation. 1
Clinical Recognition
Norovirus presents with acute onset symptoms after a 12-48 hour incubation period, characterized by:
- Nonbloody diarrhea and vomiting (some patients experience only one symptom) 2
- Nausea and abdominal cramps 2
- Low-grade fever and body aches may occur 2
- Symptoms typically self-resolve in 1-3 days in healthy individuals 2, 1
- Prolonged illness lasting 4-6 days occurs in young children, elderly persons, and hospitalized patients 2
Rehydration Management Algorithm
Step 1: Assess Dehydration Severity
Mild dehydration: Increased thirst, slightly dry mucous membranes 1
Moderate dehydration: Loss of skin turgor, dry mucous membranes 1
Severe dehydration: Severe lethargy or altered consciousness, prolonged skin tenting, hypovolemic shock 1
Step 2: Initiate Appropriate Rehydration
For mild dehydration:
- Administer reduced osmolarity ORS at 50 mL/kg over 2-4 hours 1
- Resume appropriate diet during or immediately after rehydration 1
For moderate dehydration:
- Administer reduced osmolarity ORS at 100 mL/kg over 2-4 hours 1
- Continue maintenance fluids and replace ongoing losses with ORS until symptoms resolve 1
For severe dehydration:
- Treat as medical emergency with immediate intravenous isotonic fluids in 20 mL/kg boluses 1
- Transition to ORS once stabilized 1
Step 3: Adjunctive Therapy
- Ondansetron can increase success rate of oral rehydration and minimize need for IV therapy and hospitalization 3
- Antiemetics were used in 33% of norovirus-positive episodes in real-world practice 4
- Avoid empiric antibiotics (used inappropriately in 7% of norovirus cases) 4
Infection Control Measures
Hand hygiene is critical:
- Handwashing with soap and running water for minimum 20 seconds is most effective 2, 1
- Alcohol-based hand sanitizers (≥70% ethanol) are adjuncts only, not substitutes for soap and water 2
Isolation and exclusion:
- Exclude ill food handlers, childcare workers, and patient-care workers until 48-72 hours after symptom resolution 2
- Isolate ill residents/patients in institutional settings until 24-48 hours after symptom resolution 2
Environmental disinfection:
- Use chlorine bleach solution at 1,000-5,000 ppm (1:50-1:10 dilution of household bleach) or EPA-approved disinfectant 2
- Clean surfaces first to remove soiling, then disinfect 2
Special Population Considerations
Elderly patients:
- Norovirus-associated deaths reported in elderly persons, particularly in long-term care facility outbreaks 2, 1
- Maintain heightened vigilance for dehydration 1
Immunocompromised patients:
- Can develop chronic norovirus diarrhea lasting months to years 2, 5
- Mortality rates up to 25% reported in allogeneic stem cell transplant patients 5
- Treatment options remain limited; nitazoxanide, ribavirin, and enterally administered immunoglobulin have been tried with varying results 6
Critical Pitfalls to Avoid
- Do not rely on alcohol-based sanitizers alone - norovirus requires soap and water for effective hand decontamination 2
- Do not prescribe empiric antibiotics - norovirus is viral and antibiotics are inappropriate 4
- Do not allow premature return to work - viral shedding peaks 2-5 days after infection and continues for average of 4 weeks 2, 5
- Recognize presymptomatic transmission - infected persons may be contagious 24-48 hours before symptoms appear 5
- Only 10-100 viral particles required for infection, making transmission extremely efficient 5