• Hepatitis A
• Hepatitis B

Hepatitis A

Hepatitis A virus is common cause of liver inflammation (hepatitis) worldwide. The primary mode of spread of hepatitis A virus is the fecal-oral route through contaminated food and water. The virus can also be transmitted by close and intimate contact.

Many patients with hepatitis A virus infection experience merely flu-like symptoms. These patients may not be aware that they have been infected with hepatitis A virus. In some patients with more severe symptoms, nausea, poor appetite, abdominal pain, fatigue, yellow eyes and skin (jaundice), and dark urine can last weeks to months. Very rarely, severe liver failure can lead to coma and death. However, most patients with acute viral hepatitis recover completely from their infection. Unlike viral hepatitis B and C, hepatitis A virus does not cause chronic persistent liver infection.

Patients who recover completely develop blood antibodies against the hepatitis A virus. Antibodies are proteins produced by special immune cells (usually white blood cells). Antibodies specifically target and destroy invading organisms like viruses and bacteria. After viral hepatitis A infection, the blood antibodies will remain and provide life-long immunity against future infections by the same virus.

Aside from personal hygiene, immunoprophylaxis (prevention of infection by immunization) remains the most effective approach for the control of hepatitis A. Immunoprophylaxis is a process of providing immunity for individuals who never had prior hepatitis A infection. Immunoprophylaxis can be accomplished either by administering immunoglobulins or by hepatitis A vaccines. Immunoglobulins are antibodies some of which are directed against the hepatitis A virus and can provide protection against infection within one day of administration. However, the protection only lasts two to four months. Hepatitis A vaccines are made of killed hepatitis A viruses. The vaccine stimulates the body's immune system to produce antibodies against hepatitis A virus. Protection from hepatitis A vaccines takes approximately two weeks to develop. After two doses of hepatitis A vaccine, the protection against hepatitis A infection can last longer than ten to twenty years.

Immunoglobulins are useful in situations where immediate protection against hepatitis A is necessary. For example, immunoglobulins are used to protect household contacts of patients with acute viral hepatitis infection. Protection is only effective if given within 2 weeks of exposure. Immunoglobulins can also be used to protect travelers to regions with high hepatitis A infection rates, when the travelers have to depart sooner than the vaccines can take effect. These travelers can receive both the immunoglobulins and the vaccines simultaneously, and be protected immediately as well as for longer term.

Hepatitis A vaccines are considered for individuals in high-risk settings, when immediate protection is not necessary. Examples include frequent world travelers, sexually active individuals with multiple partners, homosexual men, individuals using illicit drugs, employees of day care centers, and certain health care workers, and sewage workers.

Two hepatitis A vaccines are commercially available in the United States. These vaccines are called HAVRIX and VAQTA. These vaccines are highly effective and can provide protection even after only one dose. Two doses are recommended for adults in order to provide more prolonged protection (10-20 years) against hepatitis A infection. Both vaccines are administered by injection at the deltoid muscles of the upper arms. Both vaccines are well-tolerated. The side effects are mild. They include soreness at the injection site, headache, and fever.

From the Doctors at MedicineNet.com

Sexually Transmitted Diseases in Women (STDs) - Learn and become aware of common STDs in women, including descriptions, symptoms, diagnosis, and treatments of each type of infection. Source:MedicineNet Human Immunodeficiency Virus - Read about HIV (human immunodeficiency virus) causes, symptoms, treatment, prevention, transmission, facts, testing, research (into vaccines), statistics and AIDS (acquired immunodeficiency syndrome). Source:MedicineNet Sexually Transmitted Diseases in Men (STDs In Men) - Medical information about the prevention and treatment of sexually transmitted diseases (stds) Source:MedicineNet Read 64 more Hepatitis Immunizations related articles ... Grapefruit Compound Inhibits Hepatitis C Virus Diabetes Boosts Liver Cancer Risk in Hepatitis, Cirrhosis Cases Hepatitis A Vaccine Best Bet to Treat Virus Drug May Help Reverse Clotting Deficiency Key Factors Spur Hepatitis C Treatment Success Sharp Rise in U.S. Hepatitis C-Related Deaths Needlestick Injuries Common Among Surgery Students