Epidemiology of hepatitis B

a. Was isolated from blood, saliva, semen, vaginal or cervical secretions and wound exudates.

b. Higher incidence in the personnel working in blood bank, doctors, nurses, Down syndrome, hemophilia, thalassemic, sickle cell patients with hemodialysis, homosexuals, drug addicts, the immunosuppressed.

c. Incubation period of 45 to 160 days, averaging 120 days.

d. There are chronic carriers of HBV, defined as a person with AgsHB serum positive for 6 months or more.

e. Not transmitted through fecal-oral or water.

f. Worldwide, causing not only acute hepatitis but also chronic, cirrhosis and primary hepatocellular carcinoma.

g. Increased mortality and greater tendency to form chronic HAV.

Transmission

a. Sexual activity.

b. Parenteral.

c. Intimate Contact: prisons, asylums and hospitals.

d. Inoculation accident contaminated needles, razors or knives, ingestion of contaminated material.

e. Mother-infant and perinatal: micro transfusions mother-infant during delivery, contact with infected secretions in the birth canal or ingested through breast feeding.

f. With infection in the third trimester of pregnancy affects 75% of the children, not when it is in the first quarter. When Mom and AgsHB Age, are chronic carriers in 90% of cases.

Antigens

1. AgsHB: located in the outer covering of the virus, an early indicator of the disease, appears 1 to 2 weeks before the start, staying for 3 months or for indefinite periods (chronic carrier).

2. Anti-shb: Indicates recovery or immunity occurs between 1 to 4 months, remains indefinitely in 80% of cases.

3. AgcHB not appear in their blood but antibodies are important, says AcHB IgM IgG AcHB infection early and late infection noted. The IgM Ab may coincide with the Ags, these are not indicators of immunity or no activity.

4. AgeHB: early appearance with the Ags, short-lived (1-2 months), its persistence means chronic hepatitis or chronic carrier. The permanence of a marker indicates active replication.

5. Anti-EHB: says its recovery, is shown in 5-6 months.

Clinical Features

a. Different infections ranging from asymptomatic seroconversion.

b. Subacute disease with jaundice, anorexia, nausea and malaise.

c. Fatal fulminant hepatitis.

d. Increased tendency to form anictérica: 1 in 10 children had jaundice.

e. Splenomegaly and lymphadenopathy in the beginning, and without jaundice transaminazas high until a period of 1-2 months.

f. You can start with arthralgias or arthritis of large joints accompanied by skin rash or affected small interphalangeal joints.

Locations

1. Extrahepatic

2. Pericarditis, glomerulonephritis, myocarditis, polyarteritis nodosa, cryoglobulinemia, aplastic anemia.

Clinical Evolution

a. Acute recovery.

b. Chronic hepatitis chronic carriers or 25%.

c. Cirrhosis or hepatic 15-30%.

Both chronic hepatitis and hepatocellular carcinoma, are attributed to the formation of immune complexes that are deposited in the liver sinusoids, fix complement, resulting in severe injury. AgsHB chronic carriers at risk of developing hepatocellular carcinoma 280 times more than non-carriers.

Mother-In Agshb Risks to the fetus

a. Asymptomatic chronic carriers.

b. Followed by transient antigenemia Ac immune.

c. Chronic Active Hepatitis: Standing with Ags.

d. Acute fulminant hepatitis.

Treatment

a. There is no specific treatment for acute infection.

b. Interferon is effective in some cases of chronic hepatitis B.

c. Children of mothers with AgsHB: administering hyperimmune gammaglobulin 0.5 cc IM in the first 12 hours of birth, in addition to first dose of vaccine.

Vaccination

a. You must used the 0,1, and 6 months of age 0.5 cc IM, with reinforcement of 5 years to implement.

b. It is highly immunogenic.

c. Contains particulate Ags coupled by genetic engineering.

d. Available Engerix B and Hb VAX.