The DiseaseHepatitis A is a very infectious viral cause of acute hepatitis. It is an acute illness, which means that the symptoms can come on suddenly and sharply, causing a range of clinical problems from mild illness with no symptoms to more severe illness and even, on rare occasion, acute liver failure and death. Hepatitis A eventually goes away and does not cause chronic problems.
SymptomsThe most infamous sign of hepatitis A is jaundice, which is an accumulation of a yellow chemical called bilirubin in the body's tissues. The liver usually processes this chemical, but with hepatitis A, the liver is unable to do its normal job and the chemical accumulates in the blood and ends up in tissues. When enough of this chemical accumulates it's possible to see it as jaundice, especially around the whites of the eyes.
With the exception of jaundice, hepatitis A causes symptoms similar to many other diseases. Some of the most common symptoms are loss of appetite, muscle aches, nausea and vomiting. You may notice that many of the symptoms are similar to a gastrointestinal illness. That's because hepatitis A is shed in the stool of infected individuals which explains how it is spread from person to person.
TransmissionThe virus that causes hepatitis A enters the body through the mouth, goes into the digestive system and leaves the body in the feces. Because the virus is in an infected person's stool, it's possible to spread it to other people if he or she doesn't wash their hands well after using the toilet. Other ways of transmitting the virus have also been documented, including eating contaminated food and sexual contact, especially between men who have sex with men.
When someone is exposed to the hepatitis A virus and it actually enters their body, he or she begins an incubation period during which time no signs or symptoms exist and that person won't know he or she is infected. This is because the virus needs time to multiply itself using the liver's cells. Once enough numbers of the virus have been produced, the body will start to show signs of dealing with the infection. This incubation period lasts, on average, about four weeks. This is the time the virus is usually spread because the person won't feel sick but could infect others if they come into contact with his or her stool.
DiagnosisDoctors usually need a blood test to diagnose hepatitis A, though they can also use a combination of signs, symptoms and known exposure to someone who has hepatitis A. When the hepatitis A virus infects a liver, the body's immune system begins producing special antibodies called HAV IgM, which is a short way of describing hepatitis A immune globulin M antibodies. These antibodies quickly develop after hepatitis A infection. A positive blood test for these antibodies is a strong sign of acute hepatitis A infection.
The body also produces another type of antibody, HAV IgG, which appears much later in the infection. By identifying these antibodies, doctors are able to identify the stage of infection.
ManagementHepatitis A is a self-limited infection and does not cause chronic disease. This means that the body's immune system will clear itself of the infection, usually in a couple of weeks. Medical care is usually limited to education about the disease and relieving discomfort from symptoms. However, in rare cases, complications might develop from hepatitis A infection and will require further medical care.
PreventionProper sanitation and good hand washing is a very effective defense against spreading hepatitis A. However, in the United States thousands of new cases are diagnosed each year, so vaccination is a good choice for some people.
An effective and relatively inexpensive vaccine for hepatitis A is available. Because of its effectiveness, all children at age 12 to 24 months and people who are at increased risk for hepatitis A infection should be vaccinated. People who are considered to have increased risk for infection are travelers to endemic countries, illicit drug users and men who have sex with men.