Acute Hepatitis A Infection
What is Acute Hepatitis A Infection?
Acute Hepatitis A is a liver infection caused by the Hepatitis A virus. It spreads through contaminated food or water, or close contact with an infected person. Unlike Hepatitis B and C, Hepatitis A does not cause chronic liver disease.
Most people recover fully within a few weeks to months. The infection triggers your immune system to produce antibodies that protect you for life. Young children often have mild symptoms or none at all, while adults typically experience more noticeable illness.
The virus can survive on surfaces and in food for hours or even days. This makes good hygiene and food safety essential for prevention. Vaccination offers strong protection and is recommended for travelers and people at higher risk.
Symptoms
- Fatigue and weakness that can last several weeks
- Sudden nausea and vomiting
- Pain or discomfort in the upper right abdomen
- Dark urine that looks like cola or tea
- Clay-colored or pale stools
- Low-grade fever, usually under 102°F
- Loss of appetite and unintended weight loss
- Joint pain and muscle aches
- Yellowing of the skin and eyes, called jaundice
- Itchy skin without visible rash
Young children under age 6 often have no symptoms at all. Adults are more likely to develop jaundice and severe symptoms. Symptoms typically appear 2 to 6 weeks after exposure to the virus.
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Causes and risk factors
Hepatitis A spreads when someone ingests the virus, even in microscopic amounts. This happens through contaminated food or water, often when an infected food handler does not wash their hands properly. Raw or undercooked shellfish harvested from contaminated water can carry the virus. Close personal contact, including sexual contact and living with an infected person, also spreads the disease.
Risk factors include traveling to countries with poor sanitation, using recreational drugs, working in healthcare or childcare, and living in crowded conditions. Men who have sex with men face higher risk. People with clotting factor disorders who receive plasma-derived products may also be at risk. Poor handwashing after using the bathroom or changing diapers increases transmission.
How it's diagnosed
Diagnosis requires a blood test that detects Hepatitis A IgM antibodies. These antibodies appear within 5 to 10 days of exposure and indicate a current or recent infection. The test is the definitive way to confirm acute Hepatitis A. Your doctor may also order liver function tests to check how well your liver is working.
Rite Aid offers Hepatitis A antibody testing through our add-on tests at Quest Diagnostics locations nationwide. The test helps distinguish Hepatitis A from other causes of liver inflammation. Early detection allows you to rest, hydrate, and prevent spreading the virus to others.
Treatment options
- Rest as much as possible to help your body fight the infection
- Drink plenty of fluids to prevent dehydration from vomiting or diarrhea
- Eat small, frequent meals if you have nausea or poor appetite
- Avoid alcohol completely, as it stresses the liver further
- Stop taking medications that can harm the liver, after consulting your doctor
- Avoid acetaminophen and other drugs processed by the liver
- Practice strict hand hygiene to avoid spreading the virus to others
- Get the Hepatitis A vaccine if you were recently exposed and not yet infected
There is no specific antiviral medication for Hepatitis A. The infection usually resolves on its own with supportive care. Most people recover completely within 2 months, though some may feel tired for up to 6 months. See a doctor if you have severe vomiting, signs of dehydration, confusion, or severe abdominal pain.
Need testing for Acute Hepatitis A Infection? Add it to your panel.
- Simple blood draw at your nearest lab
- Results in days, not weeks
- Share results with your doctor
Frequently asked questions
Most people recover within 2 months of becoming ill. Fatigue and weakness may persist for up to 6 months in some cases. Unlike Hepatitis B and C, Hepatitis A never becomes a chronic infection. Once you recover, you have lifelong immunity.
Yes, you are most contagious 1 to 2 weeks before symptoms appear. You can also spread the virus during the first week of illness. This is why outbreaks can spread quickly, especially in close-contact settings. Good hand hygiene is essential even if you feel fine.
Yes, the Hepatitis A vaccine is safe and highly effective. It requires 2 doses given 6 to 12 months apart for full protection. The vaccine is recommended for children, travelers to certain countries, and people at higher risk. If given within 2 weeks of exposure, it may prevent infection.
The Hepatitis A IgM test is the gold standard for diagnosing acute infection. It is highly accurate and detects antibodies within 5 to 10 days of exposure. These antibodies typically remain detectable for 3 to 6 months after infection. A positive result confirms current or very recent Hepatitis A.
In most cases, Hepatitis A does not cause permanent liver damage. The liver usually heals completely after the infection clears. Rarely, older adults or people with existing liver disease may develop severe complications. Fulminant hepatitis, a life-threatening condition, occurs in less than 1 percent of cases.
Raw or undercooked shellfish, especially oysters, are common sources. Fresh produce like berries and lettuce can carry the virus if washed in contaminated water. Food prepared by an infected person who did not wash their hands properly is another major source. Freezing does not kill the Hepatitis A virus.
You should avoid close contact with others, especially during the first week of illness. Stay home from work, school, or childcare until your doctor says it is safe to return. Wash your hands thoroughly after using the bathroom and before handling food. Avoid preparing food for others until you are no longer contagious.
Yes, about 70 percent of children under age 6 have no symptoms when infected. They can still spread the virus to others, including adults who may become seriously ill. This is why outbreaks in childcare centers can quickly spread to families. Vaccination of young children helps protect entire communities.
See a doctor if you develop jaundice, severe abdominal pain, or persistent vomiting. Seek immediate care if you have signs of confusion, severe fatigue, or bleeding. If you were exposed to someone with Hepatitis A, contact your doctor within 2 weeks. Early intervention with the vaccine or immune globulin may prevent infection.
No, once you recover from Hepatitis A, you have lifelong immunity. Your body produces antibodies that protect you from future infections. A blood test can confirm past infection by detecting Hepatitis A total antibodies. If you were vaccinated, you also have long-lasting protection against the virus.