Hepatitis A

Hepatitis A Overview

Hepatitis is a general term that means inflammation of the liver. Inflammation of the liver can result from infection, from exposure to alcohol, certain medications, chemicals, or poisons, or from a disorder of the immune system.

Hepatitis A refers to liver inflammation caused by infection with the hepatitis A virus (HAV). HAV is one of several viruses that can cause hepatitis and is one of the 3 most common hepatitis viruses in the United States. The other 2 are hepatitis B and hepatitis C.

Unlike hepatitis B and hepatitis C, hepatitis A does not cause chronic (ongoing, long-term) disease. Although the liver does become inflamed and swollen, it heals completely in most people without any long-term damage. Once you have had hepatitis A, you develop lifelong immunity and cannot get the disease again.

Because of the way it is spread, the hepatitis A virus tends to occur in epidemics and outbreaks. As many as 1 in 3 people in the United States have antibody to HAV, meaning they have been exposed to the virus, but most do not become ill. The number of cases of hepatitis A in the United States varies among different communities and has not been affected significantly by the introduction of the hepatitis A vaccine since the early 1990s.

Hepatitis A Causes

• The hepatitis A virus is found in the stools (feces) of people with hepatitis A. It is transmitted when a person puts something in his or her mouth that has been contaminated with the feces of an affected person. This is referred to as fecal-oral transmission.
  
  
  • If food or drinking water becomes contaminated with stool from an infected person (usually because of inadequate hand washing or poor sanitary conditions), the virus can quickly spread to anyone who drinks or swallows the contaminated food or water.
    
  • The virus can also be spread by eating raw or undercooked shellfish collected from water that has been contaminated by sewage.
    
  • The hepatitis A virus can be transmitted through blood transfusions, although this is extremely rare.
• People who are infected can start spreading the infection about 1 week after their own exposure. People who do not have symptoms can still spread the virus. Infection with HAV is known to occur throughout the world.
  
• The risk of infection is greatest in developing countries with poor sanitation or poor personal hygiene standards.
  
• Infection rates are also higher in areas where direct fecal-oral transmission is likely to occur, such as daycare centers, prisons, and mental institutions. 
• People at increased risk for hepatitis A infection
  
  
  • Household contacts of people infected with HAV
    
  • Sexual partners of people infected with HAV
    
  • International travelers, especially to developing countries
    
  • Military personnel stationed abroad, especially in developing countries
    
  • Men who have sex with other men
    
  • Users of illegal drugs (injected or non-injected)
    
  • People who may come into contact with HAV at work
• Workers in professions such as health care, food preparation, and sewage and waste water management are not at greater risk of infection than the general public. 
• People who live or work in close quarters, such as dormitories, prisons, and residential facilities, or work in or attend daycare facilities are at increased risk only if strict personal hygiene measures are not observed.