Anti-HAV IgM Test

What is this test?


This test looks for antibodies in your blood called IgM. The test can find out if you are infected with the hepatitis A virus (HAV).

Hepatitis is an inflammation of your liver, often caused by an infection. Most hepatitis infections are caused by 1 of 5 viruses: hepatitis A, B, C, D, or E. Because the symptoms of all of these infections are similar, this blood test can tell your healthcare provider which type of virus you may have.

Your immune system makes IgM antibodies when you are first infected with HAV. It can take 14 to 50 days to develop symptoms of hepatitis A after you become infected. The average time to get symptoms after you are infected is 30 days. IgM antibodies often begin to appear in your blood 5 to 10 days before you start having symptoms and can stay in your blood for about 6 months after the infection.

You can get HAV by eating or drinking food or beverage contaminated with the virus. The virus is also in the bowel movements of infected people. So you could get infected by coming in contact with someone who has the infection. In rare cases, you can get the virus from a contaminated needle. 

HAV infection often clears up on its own in a few weeks or months. Once you have had HAV, you will likely never have it again. This is called having immunity to the infection.  


Why do I need this test?


You may need this test if your healthcare provider believes you may have a liver infection caused by HAV. Your provider may order this test if you have symptoms of HAV and you have a history that puts you at risk of being in contact with the virus. Risk factors for HAV include:

  • Traveling to a country with high rates of HAV infection

  • Having contact with or eating contaminated food

  • Being in close contact with a person who has HAV

  • Having sex with someone infected with HAV

  • Being a man who has sex with men

  • Working at a healthcare or daycare center

  • Sharing needles for IV (intravenous) drug use

Symptoms of HAV often start suddenly and may include:

  • Extreme tiredness (fatigue)

  • Nausea

  • Vomiting

  • Stomachache

  • Fever

  • Light gray or clay-colored stools

  • The yellow color of skin, eyes (jaundice)

  • Dark-colored urine

Some people, especially children, may have HAV without symptoms. 


What do my test results mean?


Test results may vary depending on your age, gender, health history, the method used for the test, and other things. Your test results may not mean you have a problem. Ask your healthcare provider what your test results mean for you. 

Normal results are negative or nonreactive, meaning that you don’t have hepatitis A IgM in your blood.

If your test is positive or reactive, it may mean:

  • You have an active HAV infection

  • You have had an HAV infection in the last 6 months 


How is this test done?


The test is done with a blood sample. A needle is used to draw blood from a vein in your arm or hand.