Rapid hepatitis B test (HbsAg)

Of HBsAg Quick test Is a chromatographic immunoassay for the qualitative detection of hepatitis B surface antigen in human blood serum.

The hepatitis B virus consists of the nucleus and the membrane. Its genome contains double-stranded DNA. The infection is transmitted through blood or sexual contact. Incubation period - about 70 days (40-160 days). The virus is also found in other body fluids, such as saliva. It can be passed from mother to baby through contact with blood or vaginal secretions, but it is considered impossible to pass it through the placenta.

Hepatitis B virus surface antigen (HBsAg) Is part of the outer membrane of the virus. It is known as the "Australian Antigen" and is one of the first markers to appear in the blood within an average of 4 weeks (range: 1-9 weeks) of exposure to the virus. All patients who do not remain chronically infected are HBsAg negative 15 weeks after the onset of symptoms. Normally, elimination of HBsAg is observed after normalization of ALT and disappearance of clinical manifestations.

In the chronic course of hepatitis B, HBsAg is constantly detected, although it does not show replication activity (it is necessary to detect the DNA of the causative agent by PCR, determination of HBeAg and antibodies) and can remain in the body for life.

When should we take a quick test for hepatitis B?

• Increase in ALT and AST levels;
• Clinical signs of acute or chronic viral hepatitis, chronic diseases of the liver and bile ducts;
• Examination of the disease in the family / team;
• Preparation for vaccination;
• Examination of patients undergoing frequent parenteral manipulations;
• Preparation for hospitalization, surgery;
• Pregnant women and preparations for pregnancy;
• Preventive screening of donors, people at risk (health workers, children of mothers carrying HBsAg);
• Unprotected sex, frequent change of sexual partners;
• Intravenous drug users.

How to prepare for the test?

No special training is required.

Research material

Blood plasma

Possible interpretation of the results

Positive result:

• Acute hepatitis B (anti-Hbs antibodies are not detected in blood serum during the incubation or acute period);
• Fulminant course of hepatitis B (presence of anti-HBs antibodies and HBsAg in blood serum);
• Chronic hepatitis B;
• HBsAg carriage;
• False Positive Reaction - Confirmation Needed - Re-testing and determination of common HBcorAg antibodies.

Negative result:

• Absence of HBV infection (in the absence of other markers of hepatitis B);
• Acute hepatitis B is not excluded;
• Chronic hepatitis B with low intensity of replication is not excluded;
• Fulminant course of hepatitis B;
• Hepatitis B with defective (seronegative) HBsAg is not excluded;
• Mixed hepatitis B + D (Delta virus uses the surface antigen as its membrane, so the antigen may not be detected).

Resources

https://www.cdc.gov/hepatitis/hbv/hbvfaq.htm

https://www.synevo.bg/hepatit-b-hbsag/

https://spravochnik.synevo.ua/ru/gepatit/virus-gepatita-b.html