What is Hepatitis A (Hepatitis A virus infection)?

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Last updated: April 1, 2025View editorial policy

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From the Guidelines

Hepatitis A vaccination is the most effective way to prevent infection, and it is recommended for all children starting at age 12 months, travelers to regions with high hepatitis A rates, men who have sex with men, people with chronic liver diseases, and those who use illicit drugs. Hepatitis A is a viral infection that affects the liver, causing inflammation and potential liver damage. It is primarily transmitted through the fecal-oral route, often via contaminated food or water, or through close contact with an infected person 1. The symptoms of hepatitis A include fatigue, nausea, abdominal pain, jaundice, dark urine, and clay-colored stools, typically appearing 2-7 weeks after infection 1.

Key Points to Consider

  • The likelihood of having symptoms with HAV infection increases with age, with fewer than 10% of infections among children aged 0--4 years resulting in jaundice, compared to 80%--90% among adults aged ≥18 years 1.
  • The case-fatality rate for HAV infection increases with age, with 1.8% for persons adults aged >50 years compared with 0.6% for persons aged <50 years 1.
  • The hepatitis A vaccine is typically given in two doses, 6-12 months apart, providing long-term immunity 1.
  • For immediate post-exposure protection, immune globulin can be administered within two weeks of exposure 1.
  • Good hygiene practices, particularly thorough handwashing after using the bathroom and before handling food, are essential preventive measures to reduce transmission risk 1.

Prevention and Treatment

  • Vaccination is the best protection against hepatitis A, and it is recommended for all children starting at age 12 months, travelers to regions with high hepatitis A rates, men who have sex with men, people with chronic liver diseases, and those who use illicit drugs 1.
  • Treatment focuses on supportive care, including rest, adequate nutrition, and avoiding alcohol 1.
  • Unlike hepatitis B and C, hepatitis A does not cause chronic liver disease and is usually self-limiting, with most people recovering completely within a few months 1.

From the Research

Hepatitis A Prevention and Treatment

  • Hepatitis A virus (HAV) infection can be prevented through the administration of human serum immune globulin (Ig) or hepatitis A vaccine 2.
  • Ig provides approximately 90% efficacy in preventing hepatitis A, but its protection is dose-dependent and lasts for less than six months 2.
  • Hepatitis A vaccine has been shown to be effective in preventing HAV infection, with a single dose inducing antibody in 88% to 96% of subjects by 2 weeks and 97% to 100% by 1 month 3.
  • The vaccine has been compared to Ig for postexposure prophylaxis, with similar efficacy rates, although the vaccine may have a slightly lower efficacy rate 4.

Postexposure Prophylaxis

  • Ig is recommended for postexposure prophylaxis, as it has been shown to be highly effective in preventing HAV infection when given within 2 weeks after exposure 4, 3.
  • Hepatitis A vaccine may be a reasonable alternative to Ig for postexposure prophylaxis in many situations, especially considering its long-term protection 4.
  • The "Identify-Isolate-Inform" tool can be used by frontline healthcare providers to identify and manage patients presenting with exposure, infection, or risk of contracting HAV, and to offer post-exposure prophylaxis to exposed contacts 5.

Vaccination Recommendations

  • The major pediatric indications for hepatitis A vaccine are: travelers to areas with intermediate to high rates of endemic hepatitis A, children living in defined and circumscribed communities with high endemic rates or periodic outbreaks of HAV infection, and patients with chronic liver disease 3.
  • Completion of the full vaccine schedule is recommended to assure high antibody titers and likely long-term protection 3.
  • Vaccination is also recommended for individuals at increased risk of acquiring infection, transmitting infection, or developing fulminant hepatitis, or to help control epidemics 6.

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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