Hepatitis A is an infection and inflammation of the liver caused by the hepatitis A virus. It is one of several types of hepatitis.
What is going on in the body?
The liver is an important organ located in the upper right quadrant of the abdomen. It is responsible for:
filtering the blood and removing and metabolizing many drugs and toxins.
making bile, a substance that aids in the digestion of fats, the excretion of fatty and other potentially harmful substances
processing fats on carriers (including cholesterol) and storing sugars (glycogen), helping the body transfer and store energy.
making important proteins, such as those involved in blood clotting
metabolizing medications, such as barbiturates, sedatives, and amphetamines
storing vitamins A, B12, D, and several of the B-complex vitamins. The liver also stores iron and copper.
making albumin a protein that helps maintain fluid volume in the blood stream.
- helping breakdown and recycle red blood cells.
The liver is susceptible to multiple hepatitis viruses. These viruses can cause sudden, and/or chronic severe inflammation of the liver cells. Infection can occur at any age.
Yellowing of the eyes and skin, called jaundice, is often the first sign of a problem, but less often so in children. Unlike other hepatitis viruses, hepatitis A does not generally cause symptoms or disease in other parts of the body.
After exposure to the virus, the hepatitis usually occurs within 2 to 4 weeks. In industrialized countries, hepatitis A usually occurs in an epidemic setting, that is, a cluster of cases in a population that has previously been unexposed and spreads the infection one to another. These cases in an epidemic may also have a common source of exposure.
Some parts of the world have persistent, ongoing hepatitis A in a large part of the population. Vaccination in these areas has been successful in markedly decreasing the disease burden of hepatitis A
What are the causes and risks of the infection?
Hepatitis A is generally spread by food and water that is contaminated with the virus from an infected person. This is called "fecal-oral" spread because the virus is excreted in the urine and stool. So in certain areas, sewage transmits the virus when it contaminates food or water. Rarely, it is spread when a person is exposed to the blood of another person with acute hepatitis.
The following groups have a higher risk for this disease:
military personnel (due to close contact)
travelers to countries with high rates of hepatitis A infections.
injection drug users.
persons with other liver diseases.
patients with clotting factor disorders who receive factor replacement preparations (less common).
Outbreaks of hepatitis A can occur and spread in child care centers when children have asymptomatic infections.
What can be done to prevent the infection?
To prevent the infection, a person should:
eat only properly prepared food and drink clean water
wash hands well after using the toilet or diapering a child
have an injection of serum immunoglobulin if exposed to the virus and is not allergic.
have the hepatitis A vaccine. The vaccine is usually given in 2 injections that are 6 to 12 months apart. Both immunoglobulin and hepatitis A vaccine can safely be given together.
Anyone who has had hepatitis A is immune for life.
How is the infection diagnosed?
The healthcare provider may suspect hepatitis A after doing a physical examination if a patient has appropriate symptoms and signs. Diagnosis may also be suspected if liver function tests are drawn.. Another specific blood test for antibodies against hepatitis A, drawn at the same time as the liver function tests can confirm that hepatitis A is the cause of the symptoms.
Long Term Effects
What are the long-term effects of the infection?
For most people, hepatitis A disappears completely after the acute infection and there are no long-term problems. If hepatitis A infection occurs in someone who is debilitated by another disease, especially liver disease, it can be fatal.
Occasionally with acute infection other problems can occur:
What are the risks to others?
Anyone who comes into contact with a person with hepatitis A is at risk for the disease. It is most important that no one is exposed to the stool or urine of an infected person. Other bodily secretions are not likely to cause an infection.
Finding the source and preventing additional exposure to that source also is very important. People with active hepatitis A and all those in contact with them need to wash their hands after using the toilet. Infected people may need to take 1 to 4 weeks of time off from work to not expose healthy people.
What are the treatments for the infection?
Treatment of hepatitis A is supportive and includes:
drinking extra fluids to prevent dehydration
avoiding unnecessary medications, especially those that may hurt the liver (like acetaminophen <i.e., Tylenol>)
eating a well balanced diet for liver disease
- taking antinausea medications as needed
Antiviral and anti-inflammatory medications are not helpful for the treatment of hepatitis A. Acute fulminant hepatitis can cause life-threatening liver failure. This requires hospitalization and potential treatment for bleeding, as well as for any neurological and nutritional problems from liver failure. Sometimes, the only effective treatment is a liver transplant.
What are the side effects of the treatments?
The side effects of treatment for routine hepatitis A are minimal. There are few problems with the vaccine. . A person who has been exposed to the virus and is injected with serum immunoglobulin as a precaution may feel some pain at the injection site or have a mild, brief flu-like illness. Some people (those with immunoglobulin A deficiency) may have a bad reaction to the immune globulin.
A liver transplant for acute fulminant hepatitis can have many complications, including failure or rejection of the new liver. After a liver transplant, a person will need to take powerful anti-rejection medications for the rest of his or her life. Side effects of these medications increase the risk for infections, certain cancers, and other problems.
What happens after treatment for the infection?
After the hepatitis A is resolved, the person will no longer need medications. He or she can return to normal activities, even if some jaundice remains.
How is the infection monitored?
The healthcare provider will often repeat the liver function tests to assure that they are normal. Other tests, like liver ultrasound or CAT scans, are usually not required.