What is the recommended treatment and prevention for Hepatitis A virus exposure?

Treatment and Prevention of Hepatitis A Virus Exposure

For hepatitis A virus exposure, the recommended treatment includes supportive care only, while prevention involves hepatitis A vaccine or immune globulin administration within 2 weeks of exposure, with specific recommendations based on age and health status.

Post-Exposure Prophylaxis

Timing and Efficacy

• Post-exposure prophylaxis must be administered within 2 weeks of exposure to be effective 1
• When administered within this timeframe, immune globulin (IG) is 80-90% effective in preventing clinical hepatitis A 1

Recommended Prophylaxis by Population

1. Healthy persons aged 12 months-40 years:

   • Single-antigen hepatitis A vaccine is preferred over IG 1
   • Provides long-term protection and is easier to administer

2. Persons aged >40 years:

   • IG is preferred due to more severe manifestations of hepatitis A in this age group 1
   • Vaccine can be used if IG cannot be obtained

3. Special populations requiring IG:

   • Children aged <12 months
   • Immunocompromised persons
   • Persons with chronic liver disease
   • Persons for whom vaccine is contraindicated 1

Specific Exposure Scenarios

Close Personal Contact

• Administer hepatitis A vaccine or IG to all previously unvaccinated household and sexual contacts of persons with confirmed hepatitis A 1
• Persons who shared illicit drugs with infected individuals should receive hepatitis A vaccine, or IG plus vaccine simultaneously 1
• Consider prophylaxis for persons with ongoing close personal contact (e.g., regular babysitting) 1

Child Care Centers

• Administer prophylaxis to unvaccinated staff and attendees if:
  • One or more cases are recognized in children or employees
  • Cases are recognized in two or more households of center attendees 1
• In centers without diaper-wearing children, only classroom contacts need prophylaxis 1

Food Handler Exposure

• Administer vaccine or IG to other food handlers at the same establishment 1
• Patron prophylaxis typically not indicated unless:
  • The infected food handler directly handled uncooked/cooked foods AND had diarrhea or poor hygiene
  • Patrons can be identified and treated within 2 weeks of exposure 1

Schools, Hospitals, and Workplaces

• Routine prophylaxis not indicated for single cases when the source is outside the setting 1
• Emphasize careful hygiene practices instead 1
• Provide prophylaxis if epidemiologic investigation shows transmission has occurred within the setting 1

Treatment of Hepatitis A Infection

Supportive Care

• Hepatitis A is self-limited and does not result in chronic disease 2
• No specific antiviral therapy is required or recommended 2
• Focus on:
  • Maintaining adequate hydration, especially for patients with nausea and vomiting 2
  • Rest as needed
  • Nutritional support (no specific dietary restrictions) 2

Medication Management

• Use caution with medications metabolized by the liver 2
• Avoid hepatotoxic medications during acute phase 2
• If pain relief needed:
  • Acetaminophen at reduced doses may be used
  • NSAIDs generally avoided during acute infection 2

Hospitalization Criteria

• Dehydration
• Signs of fulminant hepatitis A
• Pre-existing liver disease
• Patients over 49 years (higher risk for fulminant disease, mortality rate increases from 0.3% overall to 1.8%) 2

Prevention for International Travelers

Pre-Travel Vaccination

• All susceptible persons traveling to countries with high or intermediate hepatitis A endemicity should be vaccinated 1
• Hepatitis A vaccination is preferred over IG 1
• First dose should be administered as soon as travel is considered 1

Specific Recommendations by Population

1. Healthy persons aged <40 years:

   • One dose of single-antigen hepatitis A vaccine at any time before departure 1

2. Special populations requiring additional protection:

   • Older adults
   • Immunocompromised persons
   • Persons with chronic liver disease or other chronic medical conditions
   • If departing in <2 weeks, should receive initial vaccine dose PLUS IG (0.02 mL/kg) at a separate injection site 1

Disease Course and Monitoring

• 10-15% of patients may experience symptom relapse during the 6 months following acute illness 2
• Continue supportive care through these episodes 2
• Overall mortality rate is 0.3%, increasing to 1.8% in adults over 49 years 2

Common Pitfalls and Caveats

• Post-exposure prophylaxis is ineffective if administered >2 weeks after exposure 1
• The combination hepatitis A/hepatitis B vaccine is not recommended for post-exposure prophylaxis due to lack of data 1
• In common-source outbreaks, prophylaxis should not be provided after cases have begun to occur 1
• Persons who receive vaccine should complete the series according to the licensed schedule 1