What is Hepatitis A (infectious hepatitis)?

From the Guidelines

Hepatitis A vaccination is the most effective way to prevent the disease, and it is recommended for all children starting at age 12-23 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. The vaccine is typically given in two doses, 6 months apart, providing long-lasting immunity 1. For immediate post-exposure protection, immune globulin can be administered within two weeks of exposure, which is greater than 85% effective in preventing hepatitis A 1. Symptoms of hepatitis A include fatigue, nausea, abdominal pain, jaundice, dark urine, and clay-colored stools, typically appearing 2-7 weeks after infection. 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 without specific treatment.

Key Points

• Hepatitis A is a viral infection that affects the liver, causing inflammation and potential liver damage.
• The disease is primarily transmitted through the fecal-oral route, often via contaminated food or water, or through close contact with an infected person.
• Management focuses on supportive care, including adequate rest, proper nutrition, and avoiding alcohol.
• Practicing good hygiene, particularly thorough handwashing after using the bathroom and before handling food, is essential for preventing transmission.
• The case-fatality rate for HAV infection increases with age, and is also increased among persons with chronic liver disease, who are at increased risk for acute liver failure 1.

Prevention

• Vaccination is the best protection against hepatitis A.
• Immune globulin can be used for immediate post-exposure protection.
• Good hygiene practices, such as handwashing, can help prevent transmission.

Treatment

• Supportive care, including rest, nutrition, and avoiding alcohol, is the primary treatment for hepatitis A.
• Most people recover completely within a few months without specific treatment.

From the Research

Hepatitis A Overview

• Hepatitis A is a common viral infection worldwide that is transmitted via the fecal-oral route 2.
• The incidence of infection in the United States decreased by more than 90% after an effective vaccine was introduced, but the number of cases has been increasing because of large community outbreaks in unimmunized individuals 2.

Symptoms and Diagnosis

• Classic symptoms include fever, malaise, dark urine, and jaundice and are more common in older children and adults 2.
• People are most infectious 14 days before and seven days after the development of jaundice 2.
• Diagnosis of acute infection requires the use of serologic testing for immunoglobulin M anti-hepatitis A antibodies 2.

Prevention and Treatment

• Routine hepatitis A immunization is recommended in children 12 to 23 months of age 2, 3.
• Immunization is also recommended for individuals at high risk of contracting the infection, such as persons who use illegal drugs, those who travel to areas endemic for hepatitis A, incarcerated populations, and persons at high risk of complications from hepatitis A, such as those with chronic liver disease or HIV infection 2, 3.
• The vaccine is usually recommended for pre- and postexposure prophylaxis, but immune globulin can be used in patients who are too young to be vaccinated or if the vaccine is contraindicated 2, 4.
• Hepatitis A vaccine administered to persons after exposure to the hepatitis A virus has been compared directly with immune globulin, which is known to be highly effective in preventing hepatitis A when given within 2 weeks after exposure to the virus 5.

Vaccine Efficacy

• The hepatitis A vaccine offers good protection after exposure, with low rates of hepatitis A in both vaccine and immune globulin groups 5.
• Although the study's prespecified criterion for noninferiority was met, the slightly higher rates of hepatitis A among vaccine recipients may indicate a true modest difference in efficacy and might be clinically meaningful in some settings 5.
• The vaccine has other advantages, including long-term protection, and it may be a reasonable alternative to immune globulin for postexposure prophylaxis in many situations 5.