Hepatitis A

Hepatitis is an inflammation of the liver. Hepatitis A (a specific type of hepatitis) is a viral infection that's sometimes called infectious hepatitis. It usually lasts less than two months and most people recover completely.


Anatomy
Your liver is found behind your lower ribs on the right side of your abdomen. It's normally the size of a football. The liver fights infection and controls bleeding. It also produces bile, which assists with food digestion, stores energy, and removes drugs and other harmful products from your blood. The liver is essential for life.

Causes/associated factors
Generally, hepatitis can be caused or aggravated by a variety of factors, including medications, alcohol, toxins, parasites, bacteria and viruses. Specifically, hepatitis A is caused by the hepatitis A virus (HAV), which infects cells of the liver. It is excreted in bile and shed in the stool of infected persons. The virus does not remain in your body after the infection. Once you've had hepatitis A, you cannot get it again.
You're at an increased risk for hepatitis A if you:

are a homosexual or bisexual male
live with or have sexual contact with someone who has hepatitis A
live in or travel to countries where hepatitis A is prevalent
have chronic liver disease
use illegal drugs
have a blood clotting disorder
have an occupational risk (work with hepatitis A-infected primates or conduct hepatitis A research)

Transmission
Hepatitis A primarily spreads through fecal-oral contact. People who have active cases of hepatitis A shed the virus in their feces and can contaminate any surface they touch if infected stool is on their hands. If you touch a contaminated surface and later touch your mouth or food, you may become infected as well. It's possible for the virus to remain active outside of the human body for several months. Children have a higher risk of infection through fecal-oral contact -- a child who has hepatitis A can easily contaminate toys shared with other children.
Hepatitis A also spreads easily through contaminated food and water and sexual contact. Rarely, hepatitis A spreads through blood or blood products.

In the United States, there's a higher than average risk of infection from hepatitis A in certain communities. You can also contract hepatitis A when traveling to areas where the condition is prevalent (for example, countries outside the United States, Canada, western Europe, Japan, Australia and New Zealand), sanitary conditions are poor, or good personal hygiene is not observed.

The incubation period (time from exposure until symptoms appear) ranges from 15 to 50 days. The average is 25 to 30 days. You're the most contagious during the one to two weeks before symptoms have even developed. You're thought to remain contagious until up to a week after jaundice develops (yellowing of the skin and whites of the eyes), if it develops at all.


Signs and symptoms
Some people have few or no symptoms, and others become very ill. Children younger than age 6 often have no symptoms or only mild symptoms that are usually not diagnosed as hepatitis A. Generally, the older you are, the more severe the symptoms can be. Symptoms usually develop quickly and may include:
fever
jaundice
dark-colored urine and light-colored stools
fatigue
loss of appetite
nausea, vomiting and diarrhea
abdominal pain

Diagnosis
The doctor will ask questions about your medical history and symptoms, and do a physical exam. Diagnosis is confirmed with a blood test, that looks for the presence of antibodies (compounds that help neutralize or destroy foreign substances in the blood) to certain components of the hepatitis A virus.

Treatment
There is no specific treatment for hepatitis A. It's important to get plenty of rest, eat well and avoid alcohol. Take only medications that have been recommended by your doctor, including prescription and over-the-counter drugs, as well as herbal medications. (Both alcohol and certain medications are broken down by the liver, which creates an added strain on the already inflamed organ.) Handle urine and infected feces carefully by wearing gloves and thoroughly washing your hands afterward. Disinfect toilets, and dispose of diapers carefully.
Within two months, most people make a full recovery without complications.


Complications
Some people may be ill for as long as six months, and others may have a relapse after an apparent recovery. Rarely, hepatitis A can lead to liver failure. In some very rare cases, it can be fatal. Those who already have a chronic liver disease are at highest risk for severe complications.

Pregnancy-specific information
Immune globulin (a protein that can act as an antibody to prevent the disease from developing) is safe for mother and baby during pregnancy. Vaccine safety during pregnancy has not been determined, but the theoretical risk is expected to be low. Discuss the benefits and risks of vaccination with your doctor if you're at high risk of exposure to the hepatitis A virus.

Senior-specific information
As you get older, you're at greater risk for developing serious symptoms of hepatitis A. If you think you were or could be exposed to the virus or you're considering international travel in the near future, consult your doctor about the need for treatment or vaccination.

Prevention
Through vaccination, hepatitis A is one of the most preventable diseases in the United States. The hepatitis A vaccine is made from an inactivated form of the hepatitis A virus and is given in two injections. Immunity develops within a month of the first dose and after the second dose the vaccine is 94 to 100 percent effective in preventing the disease.
At least one-third of all reported cases of hepatitis A occur in children under age 15. Because these children often have no symptoms or only mild symptoms but can easily spread the infection, the hepatitis A vaccine is now recommended for all children at age 2 and up who live in communities with a higher than average rate of hepatitis A. Consult your local public health department or ask your doctor to determine if you live in one of these communities. The vaccine is also available for anyone who wants immunity to the disease. Itdisease, including those who have chronic liver disease due to hepatitis C.

For both children and adults, the hepatitis A vaccine is given in two shots in the upper arm. The first dose of vaccine should be given at least four weeks before any anticipated exposure (if you'll be traveling to an area where hepatitis A is prevalent, for example). The second dose is given six to 12 months (depending on the vaccine brand) after the first dose. It's not yet known how long the immunity lasts or if a hepatitis A booster will be needed.

For people over 18, a combined hepatitis A and hepatitis B vaccine is available. You'll need three doses. The second dose is given one month after the first, and the third dose is given six months after the first. (This is the same schedule as the hepatitis B vaccine.)

Adverse reactions to the hepatitis A vaccine are relatively minor, usually beginning three to five days after the vaccination and lasting for one to two days. The most common reactions are pain, soreness, redness and swelling at the injection site. Some children may also experience headaches and loss of appetite or feeding problems. Adults may experience fever, headache and a general feeling of discomfort. Very rarely, an allergic reaction can occur soon after the shot.

Immunization may be postponed if you or your child have a moderate to severe acute illness. The vaccine is not recommended for anyone who's had a serious reaction or allergy to a prior hepatitis A vaccination or any of its components.

If you've already been exposed to hepatitis A, your doctor may recommend an injection of immune globulin (a protein that can act as an antibody) to prevent the disease from developing. The immune globulin is more than 85 percent effective when given within two weeks of exposure.

Immune globulin can also be given to children who are younger than age 2 if they're at high risk of being exposed to the virus. Travelers can also be protected with immune globulin if they're leaving the country in less than four weeks and don't have time for the first dose of vaccine to become effective. Depending on the amount given, the immune globulin can protect you for up to five months.