Learn about hepatitis A virus (HAV) testing

The article is professionally consulted by Master, Doctor Tran Thi Vuong - Doctor of Microbiology - Laboratory Department - Vinmec Hai Phong International General Hospital

Hepatitis A virus can cause acute hepatitis and spreads quickly through the gastrointestinal tract. Currently, the rate of people infected with hepatitis A is quite high in the community. In addition to recognizing the clinical signs, testing is the most effective method to help diagnose and monitor the disease.

Hepatitis A is a viral disease that damages liver cells and reduces liver function. Damage in people with hepatitis A can range from mild to severe.
Hepatitis A virus (Hepatitis A Virus - HAV) is transmitted through the gastrointestinal tract, possibly from food, drinking water or food contaminated with the virus but not sterilized. During the disease process, the virus is eliminated through feces, so the risk of infection is very high in the community.
According to research, more than 90% of adults are infected with hepatitis A virus at least once in their life and have no symptoms or transient mild symptoms. This disease can clear up on its own after 2-4 weeks, in rare cases it requires treatment. Disease caused by HAV can cause acute hepatitis, but not chronic hepatitis. Patients after treatment will recover completely and have lifelong immunity to the disease.
Clinical symptoms of a typical case:
After an incubation period of 15-45 days, the disease begins to progress suddenly with manifestations such as nausea, vomiting, loss of appetite, fever, malaise and pain belly. Within a few days to a week, dark urine (bilirubinuria) appears; Pale stools (deficiency of the pigment bilirubin) may also be observed. This is followed by jaundice and pruritus (40 - 70% of cases). Initial signs and symptoms usually subside as jaundice develops, and jaundice usually peaks within two weeks. Laboratory abnormalities include: elevated liver enzymes (GOT, GPT), serum bilirubin, and serum GPT usually higher than serum GOT.
In addition, people who are vaccinated against hepatitis A will also form protective antibodies if the vaccine is optimally effective. In developed countries, the incidence of HAV decreased significantly after HAV vaccination.

The main purpose of conducting a hepatitis A virus test (HAV test) is to find antibodies to the hepatitis A virus in the patient's blood. Thereby, it is possible to diagnose acute hepatitis A in people with suspicious signs. Hepatitis A virus testing is also done to help the clinician determine the extent of liver damage, as well as consider the patient's response to treatment. In addition, HAV testing can be performed to find out whether patients with previous hepatitis A have completely recovered or are currently infected and to evaluate the effectiveness of the vaccine. Currently, testing for hepatitis A virus is very necessary, playing an important role in confirming the diagnosis, taking measures to prevent its spread and finding appropriate treatment for the disease.

People should have an HAV test when:
There are signs of suspected acute hepatitis A virus infection such as: low-grade fever, fatigue, loss of appetite, jaundice, yellow eyes, digestive disorders, dark urine color, discolored stools... Indicated to monitor the treatment process and help determine the body's ability to protect after infection or vaccination. Is prescribed by a doctor to evaluate the effectiveness of hepatitis A treatment. There is a family member with hepatitis A.

To diagnose hepatitis A, your doctor may order some of the following tests:
4.1 HAV-IgM antibody test Normally, after being infected with the virus, the incubation period is about 7-10 days, During this time, the body makes HAV-IgM antibodies to fight the virus that causes the disease. The test for HAV-IgM antibodies will be accurate after about 2 weeks of infection, after 3-12 months, anti-HAV antibodies will gradually decrease and disappear.
If HAV IgM result is negative: indicates that you are not infected with hepatitis A virus. If HAV IgM antibody result is positive: There are two possibilities, one is that the patient is having acute hepatitis A and the other is have had the disease in the past, the disease has recovered, and the IgM antibodies are still present or vaccinated recently, so there are still circulating antibodies. In this case, to determine whether the patient is suffering from acute hepatitis A or not, it is necessary to monitor clinical signs in combination with biochemical blood tests such as liver enzymes, bilirubin... 4.2 Antibodies test HAV-IgG antibodies This antibody begins to appear at 3 weeks after infection with the virus and increases gradually in the blood, they will not disappear but also remain in the blood to protect the body from the invasion of the virus.
Positive result: Evidence of recent/long-standing infection with hepatitis A or vaccination that induces a good immune response. Negative result: No history of disease or vaccine therapy is not guaranteed to be effective. In addition to the 2 hepatitis A virus tests used to detect the presence of antibodies to the hepatitis A virus, the patient should also undergo liver function tests (GPT, GOT, GGT, ALP). , bilirubin index... to diagnose and determine disease status.
Currently, most of the HAV immunological products usually combine 2 types of HAV IgM and HAV total (diagnosing HAV IgM and HAV IgG). The combination of these two test results, along with the liver enzyme tests and bililubin, will help your doctor diagnose your medical condition (if any) or your body's immune status to the HAV virus at the time of the test.
In summary, the HAV test is indicated with the main purpose of finding the presence of circulating antibodies in the patient's blood. In order to limit errors in the test process leading to inaccurate results, patients should visit reputable medical addresses. Currently, the Laboratory - Vinmec International General Hospital is one of the leading prestigious addresses in the country, trusted by a large number of patients for general examination and testing for hepatitis A virus (HAV). in particular. Thanks to the use of modern machines and equipment for testing and analysis, it has provided accurate information, helping doctors to assess the overall health of the person being tested, early detection. disease and suggest a timely treatment plan. In particular, with a space designed according to 5-star hotel standards, Vinmec guarantees to bring patients the most comfort, friendliness and peace of mind when visiting and receiving treatment at the hospital.
In particular, Vinmec currently has advanced - advanced hepatobiliary screening packages that can help detect Hepatitis Virus at an early stage even when no symptoms appear.
Choose a comprehensive hepatobiliary screening package at Vinmec to help customers:
Evaluate the liver's ability to work through liver enzyme tests; Evaluation of bile function; vascular nutrition; Early screening for liver cancer; Perform tests such as: Total blood cell analysis, blood clotting ability, screening for hepatitis B, C. Assessment of hepatobiliary status through ultrasound images and diseases that have the potential to affect liver disease / make liver disease worse. In-depth analysis of parameters to evaluate hepatobiliary function through laboratory and subclinical; the risk of affecting the liver and early screening for hepatobiliary cancer.