How common is viral hepatitis?It is estimated that
Hepatitis A virus infection prevalence approaches 100 % by age of 5 years in developing countries.
Hepatitis B accounts for 20 -25 % of all acute
viral hepatitis in children .
Hepatitis D coexists along with hepatitis B.
Hepatitis C virus is usually seen in children with thalassemia, sickle cell disease, hemophilia and children undergoing hemodialysis. Hepatitis E is an important agent in sporadic and epidemic hepatitis in our country. Recently Hepatitis F and G viruses have also been identified.
HEPATITIS AIt spreads by person to person contact and feco-oral route. Parenteral transmission is rare.
Prevalence and natural history of Hepatitis B
India falls into intermediate category of HBsAg prevalence with a carrier rate of 4.2 %. In < 10 years old, the infection is mostly silent however, the chances of becoming a chronic carrier is higher. If a newborn is infected, he rarely suffers but has 90 % chance of becoming a carrier. HbeAg positivity in the mother predisposes to neonatal HBV infection. 25 % of all HBsAg positive new-borns develop chronic liver disease by third to fourth decade of life.
Mode of transmission
Vertical transmission from mother to child, horizontal transmission from close contact in the family and parenteral and sexual transmission.
HEPATITIS C AND DHepatitis C behaves like hepatitis B and Hepatitis D is a defective virus requiring HBV infection for its propagation. Coinfection causes more severe acute disease and carries a higher risk of fulminant hepatitis. Hepatitis C vaccine is not currently available and Hepatitis D infection can be prevented by universal immunisation with Hepatitis B vaccine.
HEPATITIS EIt is a major agent for enterically transmitted non A non B hepatitis. It is an acute self limiting disease resembling HAV infection but has greater morbidity and mortality in pregnant women. Anti HEV IgM is the serological marker.
HEPATITIS GIt is a parenterally transmitted virus, which is closely associated with HCV infection but is unclear whether HGV can cause clinically significant disease.