What is the treatment for norovirus?

Treatment of Norovirus Infection

Norovirus treatment is entirely supportive, focusing on hydration and symptom management, as no specific antiviral therapy is currently available for routine clinical use. 1, 2

Primary Treatment Approach

Supportive Care

• The mainstay of treatment is early correction of dehydration and maintenance of fluid status and nutrition. 2
• Oral rehydration is preferred for mild to moderate dehydration 2
• Intravenous fluids may be necessary for severe dehydration or persistent vomiting 2
• The illness is typically self-limiting, lasting 12-72 hours in immunocompetent individuals 1

Key Clinical Principle

The focus should be on preventing complications from dehydration, which can lead to hospitalization and, in severe cases, death—particularly in developing countries and vulnerable populations 2. Most patients recover without specific intervention beyond fluid replacement.

Special Population: Immunocompromised Patients

Clinical Considerations

• Immunocompromised patients (including transplant recipients, those with chronic lymphatic malignancies, or receiving alemtuzumab) are at risk for prolonged infection lasting months to years, with potential for severe malnutrition, villous atrophy, and continuous viral shedding. 1, 3, 4
• A considerable mortality rate of up to 25% has been reported in allogeneic stem cell transplant patients 1

Management Strategy

• Reduction of immunosuppression should be considered when clinically feasible, as this has been associated with resolution of chronic norovirus infection. 4
• Experimental therapies reported in case series include nitazoxanide, ribavirin, and enterally administered immunoglobulin, though evidence remains limited and results vary 3, 5
• These patients require prolonged hospitalization and intensive supportive care 5

Infection Control Measures (Critical for Outbreak Management)

Hand Hygiene

• Handwashing with soap and running water for a minimum of 20 seconds is essential, as alcohol-based hand sanitizers have limited efficacy against norovirus. 1, 6
• Alcohol-based sanitizers (≥70% ethanol) may be used as an adjunct between proper handwashings but should never substitute for soap and water 1, 6

Isolation and Exclusion

• Ill staff (food handlers, childcare workers, healthcare workers) must be excluded until 48-72 hours after symptom resolution. 1, 6
• In institutional settings (hospitals, long-term care facilities, cruise ships), isolate ill individuals until 24-48 hours after symptom resolution 1, 6
• Do not require negative stool results prior to returning to work 6

Environmental Disinfection

• After initial cleaning, disinfect contaminated surfaces using chlorine bleach solution at 1,000-5,000 ppm (1:50 to 1:10 dilution of household bleach) or EPA-approved disinfectants. 1, 6
• Pay particular attention to bathrooms and high-touch surfaces such as door knobs and handrails 6
• Standard alcohol-based disinfectants are insufficient 6

Important Clinical Pitfalls

Common Mistakes to Avoid

• Do not rely on alcohol-based hand sanitizers as primary hand hygiene—they are inadequate against norovirus. 6
• Do not allow ill healthcare workers to return to work before 48-72 hours after symptom resolution, even if they feel better 1, 6
• Do not transfer potentially exposed but asymptomatic patients or staff to unaffected areas for typically 48 hours after exposure 6
• Avoid bare-hand contact with ready-to-eat foods as a preventive measure 1, 6

Diagnostic Considerations

• Real-time PCR is the diagnostic method of choice (sensitivity 94%, specificity 92%) 1
• Collect stool specimens within 72 hours of symptom onset for optimal diagnostic yield 1, 6

No Role for Antimicrobials

Antibiotics and standard antivirals have no role in norovirus treatment. 1, 2 The infection is viral and self-limiting in immunocompetent hosts, making antimicrobial therapy both ineffective and potentially harmful through unnecessary side effects and promotion of resistance.