WORLD HEPATITIS DAY

Types of Viral Hepatitis

• Hepatitis A, caused by hepatitis A virus (HAV)

• Hepatitis B, caused by hepatitis B virus (HBV)

• Delta hepatitis, caused by hepatitis D virus (HOV)

• Hepatitis C, caused by hepatitis C virus (HCV)

• Hepatitis E, caused by hepatitis E virus (HEV)

Hepatitis B

• Caused by hepatitis B virus (HBY), belonging to the group of hepadna viruses.

Epidemiology

• Incubation period is about 90 days (50--150 days).

• Humans are the only source of infection, being individuals incubating or suffering from acute hepatitis, asymptomatic carriers or persons with chronic liver disease.

• Major route of transmission is parenteral but occasionally non-parenteral.

• Commonly follows transfusion of infected blood or blood products, injections with contaminated needles, intravenous drug use with needle sharing, tattooing and acupuncture. Albumin solutions and gamrnaglobulins are free of risk. At present, HBY accounts for only less than 10% cases of post-transfusion hepatitis.

• Non-parenteral means of transmission include spread through body fluids like saliva, urine, semen and vaginal secretions. However, this requires close personal contact, sexual intercourse and male homosexuality.

• Mother-to-child spread (perinatal transmission) is also common. It could be either transplacental transmission or transmission at or soon after birth.

• The groups with high-risk rates of HBY infection include spouses of acutely infected persons, sexually promiscuous males (homosexuals), health-care workers exposed to blood, dentists, haemophiliacs and prisoners.

• Risk of transmission of hepatitis B through needle-stick injury from an HBsAg positive person is about 30%.

• A chronic carrier state is described for HBY infection (1-20%).

• Serum HBsAg is positive in 30% cases of Down's syndrome, lepromatous leprosy, leukaemia, Hodgkin's disease, polyarteritis nodosa, patients on chronic haemodialysis and needle using drug addicts.

• The age at which a person is infected with the virus determines the disease outcome; 90% of those who acquire HBV perinatally or in early childhood will develop chronic hepatitis as their immune system cannot destroy and clear infected hepatocytes. In adults, 90% of infections are acute and only 5-10% develop into chronic hepatitis.

Prevention

• For active immunisation recombinant vaccines (containing HBsAg) are available which provide 95% efficacy against HBV infection. Since non-percutaneous routes of transmission are quite prevalent in India, this vaccine is recommended in all children. It is also recommended in high-risk groups (health workers, haemodialysis patients, injection drug users, haemophiliacs and sexual contacts of HBsAg carriers). Injections are given at 0, 1 and 6 months for full immunity. Dose is 10 µg for children under 10 years and 20 µg in children above 10 years. The duration of immunity provided is not known but protective levels of anti-HBs have been found for 5-10 years. Boosters are not recommended at present except in immunosuppressed. The vaccine is not effective in HBsAg carriers.

• Hyperimmune B immunoglobulin (HBIG) is prepared from blood containing anti-HBs. This can prevent or minimise hepatitis B. This should preferably be given within 24 hours or at most a week of exposure. Dose is 0.06 rnL/kg. Indications are accidental needle puncture, gross personal contamination with infected blood, oral ingestion or contamination of mucous membranes, and exposure to infected blood in the presence of cuts and grazes

Precautions

• Rest

• During the acute symptomatic period, complete rest and thereafter gradual ambulation.

• In high-risk patients (patients more than 50 years, pregnant and those with other major diseases) rest is continued till symptoms and signs have disappeared, and liver function tests have returned to near normal.

• Diet

• Nutritious general diet of 2000-3000 kcal/day. In the initial stage, when good diet is not tolerated, give a light diet, fruit drinks and glucose. There is no need to avoid fatty diets, but most patients cannot tolerate these diets.

• Encourage good protein intake.

• If vomiting is severe, intravenous fluids are given.

• Drugs

  • Drugs should be avoided if possible.

  • Alcohol to be avoided for next 6 months.