Hepatitis A is a liver disease caused by the hepatitis A virus. The disease has a high risk of infection. This virus is capable of causing inflammation and affecting liver function. Most patients with the disease usually go away on their own and leave no symptoms, but in some cases, without proper treatment and care, it can be debilitating and cause symptoms of acute hepatitis (liver failure. acute), this may be associated with high mortality.
1. What is hepatitis A?
Hepatitis A virus, also known as hepatitis A, is an infectious liver infection caused by the hepatitis A virus (HAV). Some people experience only mild illness that lasts a few weeks. Others have more serious problems that can last for months. The virus spreads by eating or drinking something contaminated from the stool of an infected person. They can also be spread by injection (eg, by contact with blood) but are rare because infected people become infected with the virus for a short period of time (usually <3 weeks).
The hepatitis A virus is usually not dangerous. Almost all people who get the disease go away on their own. But it may take a long time for the virus to completely clear from your body, you will need to take care of yourself in the meantime.
Figure 1: Hepatitis A virus
When infected with HAV, the body protects itself by producing two types of antibodies in sequence:
IgM first appears 2 to 4 weeks after infection and appears 2 to 6 months and then disappears. Then, IgG appeared a few weeks after the presence of IgM and is present throughout life. IgG provides long-term immunity (protection), whether from previous viral infection or vaccination . The HAV Total antibody test (IgG plus IgM) is especially helpful in confirming an individual’s long-term immunity and vaccination suitability. Specific anti-HAV IgM tests are used primarily to find the cause of acute or very recent liver disease.
2. Symptoms of hepatitis A
If you are infected with HAV, the virus is causing inflammation in your liver. Some people, especially many children, have no symptoms. Symptoms be encountered such as:
- Jaundice (yellow eyes and skin).
- Dark urine.
- Loss of appetite.
- Stomach pain.
- Light colored stools.
- Sudden weight loss.
Figure 2: Symptoms of hepatitis A
These symptoms tend to go away after about 2 months but can keep coming back for up to 6 months. HAV can infect others even after symptoms have cleared and the virus can spread about 2 weeks before symptoms appear and for the first week after they appear.
3. What do the results of the HAV Ab test mean?
A positive IgM HAV test result in a person without symptoms of hepatitis A may indicate:
Asymptomatic acute HAV infection.
Previous hepatitis A infection with prolonged presence of IgM HAV.
False positive test results occur more often in older women.
Figure 3: HAV Ab test
IgG HAV antibodies should be detected early in the treatment of acute infection or post-vaccination. HAV IgG can be detected for decades after vaccination or infection, and the resulting reaction is a manifestation of protective immunity.
To diagnose an acute HAV infection, doctors usually require a test of both IgM and IgG antibodies to hepatitis A. To confirm immunity, the IgG HAV antibody is the test of choice.
In summary, a combination of both types of HAV Ab tests can cause the following cases:
A positive total HAV Ab assay showed previous HAV exposure but did not rule out acute or very recent hepatitis. A negative HAV Ab Total test means that there has been no previous exposure to the virus and hepatitis A vaccine should be given.
HAV infection usually resolves on its own within a few weeks or months. Once you have been infected with HAV, it is possible that you will never get infected again. This is known as having immunity to infection.
4. Why is the HAV Ab test necessary?
A doctor may order an HAV Ab test if he suspects he has a liver infection caused by HAV, when he has symptoms of HAV and a history of exposure to the virus. Risk factors for HAV include:
- Travel to a country with a high prevalence of HAV.
- Contact or eat contaminated food.
- Close contact with someone with HAV.
- Having sexual intercourse with someone infected with HAV, including having sex with men.
- Work at a health care center or kindergarten.
- Sharing IV needles (intravenously) with a person suspected of having HAV.
The HAV Ab test cannot determine the effect of the virus on the liver, so the doctor will order other blood tests to check how the liver is working. Your doctor may also check for antibodies to other hepatitis viruses such as hepatitis B, E, and D if the HAV Ab test is negative.