ravilya preventive hep B

Currently available laboratory tests for hepatitis B include
1 HBsAg (hepatitis B surface antigen),
2 anti-HBs (antibody to hepatitis B surface antigen),
3 IgM anti-HBc,
4 IgG anti-HBc (antibodies to the core antigen),
5 HBeAg,
6 anti-HBe.

Because HBcAg is sequestered within an HBsAg
coat, HBcAg is not routinely detected in patients with hepatitis B.

IgM anti- HBc appears soon after the onset of infection and the detection of HBsAg,
and precedes by many weeks detectable levels of anti-HBsAg. It generally disappears after 6 to 8 months.

The presence of IgM is a marker for acute (less than 6 months) hepatitis B.
IgG anti-HBc appears somewhat later than the IgM and may persist for years.

Elevated ALT may be present both in the early and chronic phases of the disease.

HBeAg may persist for years in
patients with chronic disease and is associated with high infectivity.

HBsAg remains detectable beyond 6 months in chronic hepatitis B.

The likelihood
of becoming chronically infected with hepatitis B is inversely related
to the age at which the infection occurs. Up to 90% of infants born to
HBsAg-positive mothers will become carriers.

Between 25 and 50% of children
infected before the age of 5 will become carriers
2 Only 6 to 10% of
acutely infected adults become chronically infected. The risk of becoming a chronic carrier is the same for men and women.

3Parenteral transmission is
not associated with a higher risk of chronic disease compared with sexual
transmission.

4 Although antigen dose may affect the risk of acquiring hepatitis
B, it has no impact on chronic carrier status

Immunodeficiency can affect
response to vaccine and can be a risk factor for chronic carrier status following
an acute infection, but not to the same degree as young age.