Acute Viral Hepatitis Testing

An acute hepatitis panel of tests is used to help detect and/or diagnose an acute liver infection due to one of the three most common hepatitis viruses: Hepatitis A virus (HAV), Hepatitis B virus (HBV), or Hepatitis C virus (HCV). There are several causes of hepatitis and the accompanying symptoms, so these tests are used to determine if symptoms are due to a current infection with a virus and to identify which virus in particular is causing the disease. These tests may also help determine if someone has been exposed to one of the viruses even before symptoms develop. An acute hepatitis panel typically consists of the following tests:

• Hepatitis A antibody, IgM—If you are exposed to Hepatitis A, your body will first produce Hepatitis A IgM antibodies. These antibodies typically develop 3 to 4 weeks after first being infected and persist for about 2 to 6 months. Hepatitis A IgM antibodies develop early in the course of infection, usually about a week after the first symptoms appear, so a positive Hepatitis A IgM test is usually considered diagnostic for acute Hepatitis A.
• Hepatitis B core antibody, IgM—This is an antibody produced against the Hepatitis B core antigen. It is the first antibody produced in response to a Hepatitis B infection and, when detected, may indicate an acute infection. It may also be present in people with chronic hepatitis B when flares of disease activity occur.
• Hepatitis B surface Ag—This is a protein present on the surface of the Hepatitis B virus. It is the earliest indicator of an acute infection but may also be present in the blood of those chronically infected.
• Hepatitis C antibody—This test detects antibodies produced in response to an HCV infection. It cannot distinguish between an active or previous infection. If positive, it is typically followed up with other tests (including molecular detection of HCV RNA) to determine is the infection is a current one. 

In acute hepatitis, other tests such as bilirubin, ALT, and AST, may be requested to help diagnose and monitor the condition.

There are some other tests that may be offered, depending on the laboratory performing the tests. These include:

• HAV antibody, total and HBV core antibody, total—These tests detect both IgM and IgG antibodies and may be used to determine if someone has had a previous infection.
• HBV surface antibody—This test may be used to help determine if an infection has resolved or if a person has developed the antibody after receiving the hepatitis B vaccine and achieved immunity for protection against HBV.
• HBV e antigen and antibody – These tests are usually only performed once a person has been confirmed as being infected with HBV. They can give an indication of how infectious a person with HBV infection may be (those with hepatitis B e antigen (HBeAg) are likely to be more infectious than those with hepatitis B e antibody (anti-HBe).
• HBV DNA – These tests are usually only performed once a person has been diagnosed with HJBV infection and can determine if a person has current active infection with HBV and how infectious they are likely to be.

Some laboratories also test for CMV IgM to detect recent CMV infection (which is spread via saliva and unprotected sex) and can cause hepatitis, tiredness and night sweats.

EBV is typically associated with Glandular Fever, but can also cause hepatitis. Antibody tests are used to diagnose EBV infection.

Acute viral hepatitis testing may be requested when a person has had blood tests which reveal abnormal liver function or and/or when someone has acute symptoms associated with liver damage such as:

• Fever, fatigue
• Loss of appetite
• Nausea, vomiting, abdominal pain
• Dark urine and/or pale coloured stool
• Joint pain
• Jaundice
• Itching (pruritus)

In the presence of acute symptoms such as those listed above, a positive result is considered diagnostic for an acute infection with Hepatitis A and B. Testing acute viral hepatitis may sometimes be used to screen people who are at an increased risk for Hepatitis B or C infection or if it is known that they have been exposed. Below are listed some examples of who may be screened for acute viral hepatitis:

• People who have elevated liver enzymes (ALT and AST) with no known cause
• People who inject illegal drugs
• People with sexually transmitted diseases
• Men who have sex with men
• People with certain medical conditions that require that their immune system be suppressed (for example, transplant recipients)
• People who are in close contact with someone infected with Hepatitis B or C
• Those infected with HIV
• People who received a blood transfusion or organ transplant before July 1992 or clotting factor produced before 1987
• People on long-term dialysis
• Children born to Hepatitis B or C positive women
• For hepatitis B, people who were born in areas of the world where the virus is common, which includes Asia, Africa, southern Europe and parts of South America
• People with evidence of chronic liver disease

The table below summarises results that may be seen following testing for acute viral hepatitis:

* Note – Persons with small amounts of anti-hepatitis B core IgM in their blood are more likely to have chronic HBV infection of have been infected with HBV several months previously.

If other hepatitis tests are performed to help determine prior exposure or previous infection, they may indicate the following:

• Hepatitis A antibody, total (IgM and IgG) — if negative, no current or previous HAV infection; if positive, indicates exposure to HAV or the HAV vaccine. An IgM test must be done if an acute infection is suspected.
• Hepatitis B core antibody, total (IgM and IgG) — a positive test can indicate previous exposure to the virus. An IgM test must be performed if an acute infection is suspected.
• Hepatitis B surface antibody — if positive, it indicates that a HBV infection has resolved; depending on results of other HBV tests. A negative result may indicate that an infection has not resolved if hepatitis B surface antigen is positive. It will also be positive with a negative hepatitis B core antibody after you have received a hepatitis B vaccine. 

It is possible to be infected with more than one hepatitis virus, and an acute infection with one hepatitis virus can be superimposed on a chronic infection with a different hepatitis virus. In such cases, there may be a positive result for more than one type of virus and care must be taken when interpreting the results.

If all the viral tests are negative, then the antibody or antigen level is too low to detect or the hepatitis is due to some other cause. For more on this and other tests that may be done to determine the cause, see the article on Hepatitis.

The test results may not always be able to tell whether you have had a previous hepatitis infection or whether you have developed antibodies in response to a vaccine. Usually other types of tests are performed to provide this type of information. See the individual articles on Hepatitis A, B or C for more on this.

No. Sometimes if it is known the particular hepatitis virus a person was exposed to, then tests specific for that virus may be performed. Also, some of these tests are used for other purposes, such as monitoring the progression of disease or determining if treatment is working, and they may be run singly or in different combinations in those cases. For more about other tests used in viral hepatitis infections, see the individual articles on Hepatitis A, Hepatitis B, and Hepatitis C.