Screening of Hepatitis B
Hepatitis B Screening
Hepatitis B viral infection (HBV) screening is carried out for different reasons, including to identify antibodies produced in response to HBV infections. It can also be used to identify antigens resulting from the presence of the virus, or to detect the presence of viral DNA.
The main purpose for hepatitis B screening is:
- To check whether the patient’s symptoms are a result of a HBV infection. The doctor may need to perform a hepatitis B surface antigen (HBsAg) and hepatitis B core antibody IgM screening as part of the diagnosis. This can be carried out with tests for hepatitis A (HAV) and hepatitis C (HCV), to determine the virus responsible for the infection.
- To observe and monitor progress of chronic hepatitis B infection, and any treatment being administered.
- To monitor for recurrence of the virus in patients with prior exposure
Other reasons for screening include:
- testing at-risk populations for chronic occurrence of the infection.
- screening of blood donors to avoid cross contamination. This screening will determine whether the patient is a Hepatitis B carrier, meaning they may carry the virus but not be suffering from the disease.
- it also detects previous infections and any subsequent development of immunity.
Doctors will generally carry out just one set of tests as an initial determinant for HBV infection, to find out the cause of observed symptoms. Another specialised test may be carried out after the diagnosis, to monitor progression of the disease, or to determine if the person is a carrier of the virus.
Below is a summary of the sets of tests usually used for initial screening of HBV infection.
- Hepatitis B surface antigen (HBsAG): The test detects the type of protein existing on the viral surface. This test is an initial indicator of viral presence, and may be positive in patients before symptoms appear.
- Hepatitis B surface antibody (anti-HBs): This test detects antibodies that are produced in response to the presence of HBV antigens. It examines previous exposure and whether a person is immune or they need vaccination.
- Total anti-hepatitis B core (anti-HBc, IgM and IgG): It is used to detect and diagnose acute and chronic HBV infections.
- Anti-hepatitis B core (anti-HBc), IgM: It is used to identify acute infections, and can also be used for chronic infections.
- Hepatitis B e-antigen (HBeAG): It detects the protein that has been produced as a reaction to the virus, then released into the blood. It determines the patient’s ability to spread the virus to other people.
- Anti-hepatitis B e antibody (Anti-HBe): It detects antibodies that are produced by the body as a response to the presence of hepatitis B. The test is used to monitor patients who have recovered from acute hepatitis B infections.
- Hepatitis B viral DNA: It is used to detect the presence of hepatitis B viral DNA in the blood. A positive result means the virus is active and some patients will require treatment. It is used to monitor the progression of treatment in patients with chronic HBV infections.
- Hepatitis B virus resistance mutations: It identifies mutations that may cause the virus to be immune to treatment. It helps doctors identify proper treatment for such patients.
Though the screenings listed above are specific to HBV, other liver tests like aspartate aminotransferase (AST), alanine aminotransferase (ALT), and gamma-glutamyl transferase (GGT) may be carried out to observe and study the progression of the disease further. Doctors may even carry out a liver biopsy to determine the extent of damage to the liver.
When Should You Get A Hepatitis B Screening
Doctors will perform a hepatitis B screening when a patient presents with signs and symptoms related to the infection. The symptoms may include :
- Loss of appetite,
- Abdominal pain
- Dark urine
- Pale stools