Hepatitis A overview

Last updated May 3, 2024, by Marisa Wexler, MS
Fact-checked by Marta Figueiredo, PhD

Hepatitis A is a highly contagious viral infection that mainly affects the liver. While the infection usually resolves on its own, and does not progress to chronic disease, hepatitis A can, in rare cases, result in liver damage and failure.

It’s therefore important that patients are aware of hepatitis A risk factors, and understand potential exposure to the disease-causing virus, disease symptoms, and available treatment options. A vaccine against the hepatitis A virus is the most effective way to prevent the disease, and also is crucial for mitigating its spread and potential complications.

What is hepatitis A?

Hepatitis A is a type of viral hepatitis, a condition in which liver inflammation is caused by a viral infection. Like other forms of hepatitis, hepatitis A can damage the liver and lead to complications, but there are some important distinctions between hepatitis A and other forms of viral hepatitis.

For example, hepatitis A is more contagious than hepatitis B and C,  spreading via person-to-person contact as opposed to contact with bodily fluids. Unlike these other forms, however, it is virtually always an acute infection that clears up within a few months. In addition, a vaccine against hepatitis A is available, as is one to prevent hepatitis B; there is no vaccine against hepatitis C.

As such, strategies to prevent and treat infections vary across different forms of viral hepatitis.

The acute infection of hepatitis A can vary widely in severity. Some people have a fairly mild infection that may not cause noticeable symptoms, but other cases of hepatitis A may cause liver damage that can be serious and even life-threatening.

While death due to hepatitis A is rare, especially for patients who have access to high-quality supportive care, it can happen in some cases. The risk of liver failure and/or death from hepatitis A is highest for people who are older or who have an underlying chronic liver disorder. According to the World Health Organization (WHO), about 7,100 people died of hepatitis A in 2016, which was estimated to represent 1 of every 200 deaths that were attributed to viral hepatitis that year.

Causes

Hepatitis A is caused by an infection with the hepatitis A virus (HAV), which mainly targets the liver. This virus is mainly spread by fecal-oral transmission, in which people ingest contaminated food or water that’s been in contact with fecal matter from someone infected with the virus.

Examples include contact with food or beverages prepared by a HAV-infected person with unwashed hands, exposure of caregivers and children to infected stool in diapers, and consumption of raw shellfish harvested from waters exposed to raw sewage drains that can be contaminated with HAV-containing feces.

While it can survive for months outside the body, the hepatitis A virus can be killed by high temperatures. Freezing temperatures, however, will not deactivate it.

Hepatitis A transmission also can occur due to close personal contact, such as sharing living quarters, having sex, or sharing needles to take illegal drugs with someone who is already infected with the virus.

Because of how hepatitis A is transmitted, the disease generally is less common in parts of the world that have robust sanitation infrastructure and access to clean water. Conversely, it’s most common among people who don’t have regular access to good hygiene resources.

Risk factors for hepatitis A include:

• lack of access to clean water
• poor sanitation
• living in or traveling to a place where hepatitis A is common, including in parts of Africa and Asia, Central and South America, and Eastern Europe
• living, caring for, or having sex or sexual interplay (particularly involving the anus) with someone who is infected with HAV
• having a job where there’s a risk of exposure to fecal matter, including in daycare, healthcare, and sewages
• being homeless
• using illegal drugs.

Symptoms

After the hepatitis A virus infects the body, there’s an incubation period lasting about two to seven weeks, or as long as 1.5 months. During this time, the person won’t show obvious signs of hepatitis A, but may already be contagious and able to spread the virus to others.

Following that period, patients can experience hepatitis A symptoms that may include:

• loss of appetite
• nausea and vomiting 
• fatigue and weakness
• abdominal pain, especially in the upper right part of the abdomen
• diarrhea
• joint pain
• fever
• dark urine or light-colored stools
• yellowed skin and white of the eyes, a condition known as jaundice 
• itchy skin.

Not everyone with hepatitis A will experience symptoms of the infection. For example, hepatitis A rarely causes symptoms in young children, but these patients can still spread the virus and cause disease in other people. Symptoms and serious complications are more common when the infection occurs in adults.

Hepatitis A symptoms usually last less than two months, but some patients may have symptoms for up to six months. After that, symptoms generally resolve, although it’s also possible that patients experience a relapse, or another episode of acute infection, shortly after recovery. When this happens, it’s usually followed by a normal recovery.

After hepatitis A is resolved, people can no longer transmit the virus to others.

Diagnosis

In the presence of symptoms suggestive of hepatitis A, physicians often prescribe blood tests to assess liver health.

If these tests show signs of liver damage, or indicate that the organ is not functioning well, a hepatitis A diagnosis can be confirmed via other blood tests. Such tests typically search for antibodies made by the immune system as it fights off HAV.

Additional testing may assess the presence of genetic material from the virus itself, and help to confirm a hepatitis A diagnosis.

Treatment

There is no specific treatment for hepatitis A, nor a hepatitis A cure. Instead, hepatitis A treatment generally focuses on supportive care to help keep any infected people as otherwise healthy and comfortable as possible while their bodies fight off the virus.

The intensity of supportive care that’s needed will vary depending on how severe the infection is. Some people with mild symptoms may be able to rest at home, while others with more severe liver damage will require hospitalization for more intensive hepatitis A treatment.

Hepatitis A self-care tips include:

• getting plenty of rest
• staying hydrated
• eating a well-balanced diet
• using symptom-relieving treatments, such as pain medications, as directed by a physician
• avoiding substances that can stress the liver, like alcohol and aspirin
• maintaining an open line of communication with healthcare providers.

Complications

The vast majority of people with hepatitis A will recover from the infection without any lasting issues. After recovering, patients are typically immune to the virus for the rest of their lives.

Although long-term complications from hepatitis A are very rare, they may occur, especially in people who are older or have other underlying health problems. Complications from hepatitis A can include:

• prolonged cholestasis, where the flow of the digestive fluid bile out of the liver is stalled, which can lead to further liver damage as well as symptoms such as itching
• liver failure, in which the liver is no longer able to function properly
• kidney failure, or when the kidneys aren’t able to keep up with their job of filtering blood
• autoimmune hepatitis, where the body’s immune system begins attacking healthy liver cells instead of virus-infected cells.

Hepatitis A vaccine and prevention

The most effective way to prevent hepatitis A is to receive a vaccine targeting the hepatitis A virus. The U.S. Centers for Disease Control and Prevention recommends that all children should be vaccinated against hepatitis A between 12 to 23 months, or from age 1 to just younger than age 2. Vaccination also is recommended for older children who did not receive the vaccine in their first years, and also for adults who are at high risk from hepatitis A. Among adults who may be at risk are those in high-risk groups or traveling to places where the virus is common.

There are two types of hepatitis A vaccines now available in the U.S.; both are extremely effective when administered as directed:

• A single hepatitis A vaccine, sold as Havrix and Vaqta, is given as two injections, six to 18 months apart, with most people acquiring some protection within two weeks of the first shot.
• A combination vaccine, sold under the brand name Twinrix, protects against both hepatitis A and hepatitis B. It is given to individuals 18 years and older as 3-4 injections over the course of six months to one year.

The hepatitis A vaccines are both very safe. The most common side effects are soreness at the injection site and headache, but no serious side effects have been documented with either vaccine. That said, the vaccines are not recommended for people who are allergic to any of their components, or for use in children younger than 1 year.

In people who may have been exposed to HAV but cannot receive the hepatitis A vaccine, immune globulin — a substance collected from human blood that contains antibodies against several potential threats, including HAV — may be used as preventive therapy. For maximum protection, immune globulin should be administered within two weeks after potential exposure. However, unlike the vaccine, this approach will not provide long-term protection against hepatitis A virus infection.

In addition to vaccination, an important part of hepatitis A prevention is robust sanitation infrastructure and proper hygiene practices to reduce the spread of the virus. Prevention tips include thorough hand-washing and using safe practices when handling food.

Liver Disease News is strictly a news and information website about the disease. It does not provide medical advice, diagnosis or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.