Hepatitis B

Hepatitis B virus (HBV) is a virus that causes inflammation of the liver. Most people do not think of hepatitis as a sexually transmitted infection; however, one of the more common modes of the spread of viral hepatitis B is through intimate sexual contact. Sexual transmission is believed to be responsible for a significant percentage of the cases worldwide. (Improved screening of donated blood has diminished the risk of getting hepatitis B from blood transfusion.) Complications from hepatitis B are responsible for 1 to 2 million deaths yearly.

Hepatitis B virus can cause both an initial (acute) and a chronic form of liver inflammation. The initial phase of infection lasts a few weeks, and in most people, the infection clears. People who recover from the initial infection develop immunity to the HBV, which protects them from future infection with this virus. Still, a small percent of individuals infected with HBV will develop chronic or long-lasting liver disease. These persons are potentially infectious to others. It is the chronic form of hepatitis B that is dangerous to women. Chronic hepatitis B is associated with cirrhosis of the liver, liver failure, and liver cancer.

Transmission of hepatitis B can occur during the early phase of infection or during the chronic carrier stage. Kissing and unprotected intercourse are methods of spreading this virus. While hepatitis does not affect the reproductive organs, a pregnant woman can transmit it to the fetus if she is infected during the pregnancy. The hepatitis B virus is transmitted to a majority of the fetuses in women that are infected during pregnancy. This is potentially dangerous, since infected infants have an 80% chance of developing the chronic form of the infection.

Symptoms of hepatitis B

Only 50% of acute infections with the hepatitis B virus produce symptoms. The symptoms of hepatitis include yellow coloration of the skin or eyes (jaundice), fever, upper abdominal pain, generalized malaise, and nausea. In later stages, hepatitis B can cause edema (swelling of the legs) and ascites (fluid accumulation in the abdomen).

How can hepatitis B infection be prevented?

A highly effective vaccine that prevents hepatitis B is currently available. It is recommended that all babies be vaccinated against HBV beginning at birth, and all children under the age of 18 who have not been vaccinated should also receive the vaccination. Among adults, anyone who wishes to do so may receive the vaccine, and it is recommended especially for anyone whose behavior or lifestyle may pose a risk of HBV infection. Examples of at-risk groups include:

• sexually active men and women;
• illegal drug users;
• health-care workers;
• recipients of certain blood products;
• household and sexual contacts of persons known to be chronically infected with hepatitis B;
• adoptees from countries in which hepatitis B is common, such as Southeast Asia;
• certain international travelers who may have sexual or blood exposures;
• clients and employees of facilities for the developmentally disabled, infants and children; and
• patients with renal failure on hemodialysis.

The vaccine is given as a series of three injections in the muscle tissue of the shoulder. The second dose is administered one month after the first dose and the third dose is given five months after the second dose. In the event that a non-immunized individual (who would not have protective antibodies against HBV) is exposed to the genital secretions or blood of an infected person, the exposed person should receive purified hepatitis B immunoglobulin antibodies (HBIG) and initiate the vaccine series.

Diagnosis and treatment of hepatitis B

Liver function tests in the blood become abnormal 1-10 days after infection with the virus. Hepatitis B then can be diagnosed by detecting antibodies against the virus and by blood tests that identify the virus in the blood.

Diagnosis of HBV infection involves blood tests to detect the hepatitis B surface antigen (HBsAg, the outer coat of the virus), hepatitis B surface antibody (HBsAb), and hepatitis B core antibody (HBcAb). If the HBsAb antibodies are in the blood, their presence indicates that the person has been exposed to the virus and is immune to future infection. Furthermore, this person cannot transmit the virus to others or develop liver disease from the infection. The HBcAb antibodies identify both past and current infection with the HBV. If the HbsAg antigen is in the blood, the person is infectious to others. There are also two possible interpretations to the presence of this antigen. In one, the person has been recently infected with HBV, may have acute viral hepatitis B, and will develop immunity in the coming months. In the other interpretation, the person is chronically infected with HBV, may have chronic hepatitis, and is at risk for developing the complications of chronic liver disease.