It is estimated that approximately 350 million people worldwide have hepatitis B infection. The risk of transmission of hepatitis B virus (HBV) due to blood transfusion exceeds that of hepatitis C virus (HCV) or human immunodeficiency virus (HIV) and most people are unaware of their infection.
Acute hepatitis B infection usually refers to the first 6 months after someone is exposed to the hepatitis B virus. Once infected, some are able to fight the viral infection while in some others the infection leads to a “chronic state,” or lifelong illness. In such individuals the infection over a period of time can cause serious life-threatening problem. Hence, screening and early diagnosis of the condition is important so that due precautions and treatment if necessary can be undertaken.
Which people should be screened for hepatitis B and why?
Spread of Hepatitis B occurs through blood products, sexually as well as from mother to fetus. Screening is recommended for persons at high risk for contracting the disease. These include:-
- Hemodialysis patients
- Pregnant women
- Infants born mothers who are HBsAg-positive
- Persons known or suspected of having been exposed to HBV - donors of blood, organs, and tissues
- People born in areas where HBsAg (Hepatitis B surface antigen) prevalence is found to be equal to or more than 2%
- Men who have had sex with men
- Drug addicts using injectable drugs
- HIV positive individuals
- Patients likely to take immunosuppressive treatment or cancer chemotherapy
- Patients with increase in liver enzymes of undetermined cause
What tests are used for screening hepatitis B?
The following tests are used for HBV screening:-
Hepatitis B surface antigen:- A blood test to detect the presence of hepatitis B surface antigen (HBsAg) is used to screen people for hepatitis B. Persons who test positive can spread the infection to others. The test turns positive around 3 to 5 weeks after a person has been exposed to the virus. It persists in individuals who are chronically infected, but disappears once the infection has resolved. In brief it indicates:
|Hepatitis B surface antigen (HBsAg)||Active HBV||Screening Test for HBV infection. Sometimes may be falsely negative in some patients with active HBV. Positive person can spread infection. Persistence after 6 months indicates chronic infection.|
This test detects the presence of antibodies to the hepatitis B surface antigen i.e. if the person has been previously exposed to hepatitis B. It tests positive in persons who are immune to hepatitis B or have recovered from hepatitis B infection. It indicates that the person has protective immunity against hepatitis B and will not pass the infection to others.
|Hepatitis B surface antibody (HBsAb)||Positive test indicates patient is immune to HBV (through past exposure or vaccination)||Negative test indicates that the patient is not immune; if active HBV disease is not present, consider vaccination|
Total anti-HBc: This test detects the presence of antibodies to hepatitis B core antigen. It is positive in acute as well as in chronic infection and in those recovered from hepatitis B. There are two types of anti-HBc antibodies. The presence of the IgM subtype is indicates acute infection or reactivation of infection, whereas the IgG subtype indicates chronic infection. In brief:
|Hepatitis B core antibody (HBcAb), |
|Positive test indicates past exposure to HBV and does not indicate whether patient has active infection or has cleared infection (check HBsAg and HBsAb) |
Indicates Chronic infection
Indicates acute infection or reactivation of infection
|Negative test indicates that the person has probably has not been infected with HBV|
Frequently Asked Questions
1. Which doctor should I consult in case my test is abnormal?
You should consult a general physician, gastroenterologist or a hepatologist in case your test is abnormal.
2. Why is screening for hepatitis B important?
People infected with hepatitis B often do not suffer from symptoms. However, if the infection is present for a long duration, it results in life-threatening liver complications. Hence, early detection is necessary to treat the condition before complications develop.
3. Can there be a chart that can help with interpretation of the results?
- Testing and Public Health Management of Persons with Chronic Hepatitis B Virus Infection - (http://www.cdc.gov/hepatitis/HBV/TestingChronic.htm)
- Recommendations for Routine Testing and Follow-up for Chronic Hepatitis B Virus (HBV) Infection - (http://www.cdc.gov/hepatitis/HBV/PDFs/ChronicHepBTestingFlwUp.pdf)
- Recommendations for Identification and Public Health Management of Persons with Chronic Hepatitis B Virus Infection - (http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5708a1.htm)
Latest Publications and Research on HBV Screening
- Design and Development of a Viral Hepatitis and HIV Infection Screening Program (Hprolipsis) for the General, Greek Roma, and Migrant Populations of Greece: Protocol for Three Cross-Sectional Health Examination Surveys. - Published by PubMed
- Hepatitis B virus X protein: The X factor in chronic hepatitis B virus disease progression. - Published by PubMed
- RNA Profiling Analysis of the Serum Exosomes Derived from Patients with Chronic Hepatitis and Acute-on-chronic Liver Failure Caused By HBV. - Published by PubMed
- A same day "test and treat" model for chronic HCV and HBV infection: Results from two community-based pilot studies in Egypt. - Published by PubMed
- Quality Initiative in Clinical Practice: A Single-Institution Appraisal of Quality Metrics in the Management of Newly Diagnosed Diffuse Large B-Cell Lymphoma. - Published by PubMed