Hepatitis B

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Hepatitis B : Background Hepatitis B : Treatment
Hepatitis B : Risk Factors Hepatitis B : Prevention
Hepatitis B : Signs and Symptoms Hepatitis B : Outlook
Hepatitis B : Complications Hepatitis B : References
Hepatitis B : Diagnosis

Background

Human LiverHepatitis B is an infectious disease caused by the hepatitis B virus (HBV). The virus attacks and damages the liver, and can occasionally cause severe liver damage and even liver cancer. According to an analysis published by the Centers for Disease Control (CDC) in February 2013, about 19,000 new cases of hepatitis B occur in the U.S. each year.

Hepatitis B is transmitted by direct contact with infected blood and other bodily fluids, including semen, vaginal secretions, saliva, and open sores. It can be spread by unprotected sexual activity with an infected person, sharing infected needles during illicit drug use, accidental needle sticks by health care workers, being pierced or tattooed with infected instruments, and exposure to the blood of an infected person. Hepatitis B can also be transmitted from a pregnant woman to her baby during childbirth.

In most cases, the virus is cleared from the body after an acute infection. But sometimes the virus stays in the body and may start reproducing again at any time. In the United States, approximately 1.5 million people have chronic hepatitis B and are sources for hepatitis B transmission to others.

According to a recent study by scientists at Münster University, the hepatitis B virus has been in existence for more than 82 million years! It originally infected birds back when the dinosaurs still roamed the earth. The earliest record of an epidemic caused by hepatitis B virus was in 1883. After an outbreak of smallpox in Bremen, shipyard workers were vaccinated with human lymph. Several months later, many of the workers became ill with jaundice and were diagnosed with serum hepatitis. The source of the epidemic was discovered to be a batch of contaminated lymph.

It wasn’t until 1965 that there was a breakthrough in the understanding of the virus. Dr. Baruch Blumberg, working at the National Institutes of Health (NIH), discovered an antigen that detected the presence of HPV in blood samples. Dr. Blumberg later won the Nobel Prize for his discovery.

A vaccine against hepatitis B has been available since 1982. The vaccine is 95% effective in preventing infection and its chronic consequences.

Risk Factors

Hepatitis B is largely a disease of young adults aged 20-50 years. Men and women who have multiple sex partners are at higher risk, especially if they don’t use a condom. Other high risk groups are Asian and Pacific Islanders, men who have sex with men, people who inject drugs with shared needles, health care workers who are stuck with contaminated needles, people who receive blood transfusions, and people with a history of other sexually transmitted diseases.

People with HIV or other diseases that weaken the immune system are at greater risk of becoming infected with hepatitis B and may develop more severe health problems as a result of the infection. Chemotherapy and immune-suppressing drugs (for transplants or auto-immune diseases) are also risk factors.

Signs and Symptoms

Symptoms of hepatitis B vary depending on whether the disease is acute or chronic. In the acute phase (when a person is initially infected with hepatitis), symptoms include loss of appetite, unexplained fatigue, nausea and vomiting, jaundice (yellowing of the skin and eyes), dark urine, and unusually light colored stools. However, nearly half of those infected have atypical symptoms or no symptoms at all. Symptoms usually appear one to six months after exposure.

Most infected adults are able to fight off the virus and recover completely. However, a low percentage of adults (approximately 5%) go on to develop chronic infection. Chronic hepatitis B can cause liver damage that can later develop into cirrhosis of the liver and liver cancer. Symptoms of chronic infection include persistent jaundice, fatigue, decreased appetite, and joint pain. In severe cases, there can be fluid retention causing swelling of the belly, blood in the stool, and mental confusion. Children younger than age 5 are at much higher risk for chronic infection (approximately 50%) and infants are at an even higher risk (approximately 90%).

People who are infected with hepatitis B for more than 6 months are considered carriers (even if they do not have symptoms). This means that they can transmit the disease to others by having unprotected sex, exposing blood or open sores to others, or sharing an infected needle or syringe.

Complications

A small percentage of patients with chronic hepatitis B develop cirrhosis, or hardening of the liver. Cirrhosis causes liver tissue to scar and stop working. The only treatment for liver failure is a liver transplant, a surgery with many risks and an extended recovery period.

Chronic infection with hepatitis can also lead to liver cancer. About 80% of all primary liver cancers are caused by hepatitis B. In fact, individuals with chronic hepatitis B are 100 times more likely to develop primary liver cancer than uninfected people. Primary liver cancer is one of the deadliest cancers and has a 5-year survival rate of only 10%.

Fulminant hepatitis is a rare but extremely severe form of acute hepatitis B. Patients with fulminant hepatitis typically develop the symptoms seen in acute hepatitis B, but then suddenly (within days or weeks) develop severe, often life-threatening liver failure. Symptoms of severe liver failure include confusion, extreme irritability, fluid retention, bruising or bleeding (due to lack of clotting factors), and coma. There is no medication for fulminant hepatitis; for some people, a liver transplant is the only cure.

Pregnant women can pass the virus to their babies during the birthing process. Without prompt treatment, approximately 40% of babies born to infected mothers will develop chronic hepatitis B, and approximately a quarter of these babies will eventually die from chronic liver disease. Transmission can be prevented if babies are given hepatitis B immune globulin and the hepatitis B vaccine within 12 hours of birth.

Diagnosis

Hepatitis B infection is diagnosed with blood tests. These tests can detect the presence and amount of hepatitis B virus in the blood, as well as the presence of antibodies to the virus. Blood tests can also help determine whether there has been damage to the liver.

In patients with chronic hepatitis B, other diagnostic tests may be necessary to detect liver damage or liver cancer. These include a CT scan (ultrasound) and a liver biopsy. In a liver biopsy, a tissue sample is removed by inserting a long needle into the liver. The tissue is examined under a microscope to detect abnormalities.

Treatment

Acute hepatitis B usually resolves on its own and does not require medical treatment. If a patient has severe symptoms such as vomiting or diarrhea, IV fluids may be prescribed to restore fluids and electrolytes. There are no medications that can prevent acute hepatitis B from becoming chronic.

Chronic hepatitis B can be treated with a variety of medications. However, the disease is rarely cured. The most effective treatment is antiviral drugs, which work by keeping the virus from multiplying. However, antiviral drugs do not clear the virus from the body, and they do not have any effect after the medication is stopped.

Patients with chronic liver disease that does not respond to other treatment may be considered for a liver transplant. This procedure can be life-saving. However, in most cases, the new liver eventually becomes infected with hepatitis B.

Prevention

Fortunately, hepatitis B is usually preventable since there is an effective vaccine. Use of the vaccine has resulted in a large decrease in the number of new infections reported each year. The Advisory Committee on Immunization Practices (ACIP) recommends that all infants receive their first dose of the hepatitis B vaccine in the hospital before they are taken home. They should complete the vaccine series by age 6–18 months. Older children (up to age 18 years) who did not previously receive the vaccine should also be vaccinated. Since 2002, the vaccine has also been recommended for adults.

Because hepatitis B can be transmitted during sexual activity, another way to prevent infection is to abstain from oral, vaginal, and anal sex or to have a mutually monogamous relationship with an uninfected sex partner. When used correctly, latex condoms can lower the risk of transmission of hepatitis B, but are not 100% effective. Most other birth control methods – including the pill, IUD, diaphragm, and spermicides – don’t protect against hepatitis B.

People should not share grooming products or other items that might have blood on them, including razors, toothbrushes, fingernail clippers, etc. People who inject themselves with drugs should not share needles, syringes, or other equipment. People who get tattoos or body piercings should ensure that their artist sterilizes all needles and equipment, uses disposable gloves, and washes hands properly.

Health care workers should follow standard precautions regarding the handling of needles and sharp instruments.

Outlook

Although a diagnosis of hepatitis B can be very upsetting, the good news is that most people with hepatitis B, even those with chronic hepatitis B, can be expected to live a long and healthy life. There are several treatments available that can manage symptoms and slow down the progression of the virus.

However, there is still a need to increase awareness, to promote access to screening and treatment services, and to ensure that preventive measures are universally implemented. The World Health Organization (WHO) has several initiatives that should help. Each year the WHO sponsors World Hepatitis Day (July 28) to increase awareness and understanding of the disease. On June 5, 2014, the WHO convened a historic global partners’ meeting on viral hepatitis in Geneva, Switzerland. The group issued a “call to action” to increase global awareness, prevention, diagnosis, and treatment of the disease.

References:

1) Incidence, Prevalence, and Cost of Sexually Transmitted Infections in the United States – CDC Fact Sheet
Source: Centers for Disease Control and Prevention

2) Viral Hepatitis Fact Sheet
Source: Womenshealth.gov

3) Hepatitis B
Source: Health Aetna InteliHealth

4) Sexually Transmitted Diseases
Source: The Center for Menstrual Disorders and Reproductive Choice

5) General Information: FAQ
Source: Hepatits B Foundation

6) Chronic HBV Infections
Source: Hepatits B Foundation

7) Hepatitis B Information for Health Care Professionals: Perinatal Transmission
Source: Centers for Disease Control and Prevention

8) Hepatitis B Information for Health Care Professionals: Vaccination of Infants, Children, and Adolescents
Source: Centers for Disease Control and Prevention

9) Discovery of a More Than 82 Million Years Old Hepatitis B Virus (press release)
Source: Münster University

Posted in STI.