Hepatitis B Viruses

 

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Hepatitis B virus infection can cause acute or chronic hepatitis.

There are 8 genotypes however vaccination with the present vaccination can prevent infection of all the genotypes.

Transmission

Transmission- through direct contact with blood and blood product

                     -genital secretions

                     -during pregnancy and delivery

 

Incubation period

The incubation period is between 3 to 6 months.

 

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Clinical presentations

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Acute infection

Pre-icteric phase

Nausea, abdominal discomfort, arthralgia and skin rash.

 

Icteric phase

Jaundice, clay colour stool, and dark urine

 

Complication

Ø      Acute hepatic failure

Jaundice,

Altered state of consciousness

 

Chronic infectious

Loss of weight

Abdominal discomfort

Jaundice

Hepatosplenomegaly

Ascites

Other signs of chronic liver failure

 

Complication

Ø      Cirrhosis

Ø      Hepatocellular carcinoma

Ø      Glomerulonepheritis

 

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Investigation

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LFT- increase in transaminase level

Liver biopsy- fibrosis and necrosis

 

Diagnostic tests

Serum for HBsAg, HB core antibody

Hepatitis B

 

Acute infection          +               -                               +/+              + or -         + or –

Chronic infection       +               -                              -/+                + or -        + or –

Past resolved              -                +                              -/+               -                 +

 

 

Screening tests

Ÿ         before vaccination- test HB core antibody

Ÿ         before transplant – test HB core antibody and HBsAg

Ÿ         before donating blood- test HB core antibody

Ÿ         before in vitro fertilisation- test for HB s Ag

Ÿ         healthcare workers- test for anti-HBs

Ÿ         HIV or HCV infected patients- HBsAg, HB core antibody and anti-HBs

 

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Treatment

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Acute hepatitis

Conservative and follow up.

Test for HbsAg and HB e markers after 6 months.

 

Chronic hepatitis

Assess liver function

Liver biopsy –fibrosis and cirrhosis

HBsAg, HB e marker

HBV DNA viral load.

 

Management of Hepatitis B virus infected patients (PDF)

 

Specific treatment

Lamivudine, Adefovir and alpha interferon are licensed for treating chronic hepatitis B virus infection.

The objective of therapy for

HBeAg positive- to continue therapy till there is a change of “e” marker- HBeAg negative

HBeAg negative- the objective is to continue to treat until the Viral load is suppressed to undetectable level.

 

 

Decompensated liver disease

Therapy with interferon is contraindicated.

Liver transplant is done for most patients with decompensated liver disease. Recurrence is common after transplant.

Lamivudine and HB specific immunoglobulin is used to prevent recurrence in these patients.

 

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Prevention

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Screening of blood and blood product before transplantations has reduced the transmission in the western European countries.

Screening of pregnant mothers and vaccinating newborn babies can also be effective to prevent vertical transmission.

Universal vaccination is more effective.

The vaccine can be used even after exposure to Hepatitis B.

HB specific immunoglobulin is also effective after exposure to HBV.

 

 

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