Hepatitis A

Preventing hepatitis A

Vaccination against hepatitis A has been very effective in preventing infection before exposure to the virus. Immunization of children between 2 and 18 years old consists of two to three doses of the vaccine. Adults need a booster dose six to 12 months after the initial dose of vaccine. The initial dose will protect an individual for about four weeks after the first injection. But complete vaccination with all doses is believed to be effective for 15 to 20 years, so it's important to receive the whole vaccination series. The hepatitis A vaccine is not licensed for children younger than 2.

People who should be vaccinated include:

• Those with chronic liver disease or hemophilia
• Individuals who travel or work in developing countries; hepatitis A is the most common, vaccine-preventable infection acquired during travel.
• People in communities that have experienced a major natural disaster that has compromised water and sanitation systems. Recovery workers in those regions are also at risk.
• Children and workers in day-care centers; children living in communities with high rates of hepatitis A, such as American Indian and Native Alaskans
• Restaurant workers and food handlers
• Young people living in dorms and institutionalized individuals
• People who engage in anal/oral sex
• People who frequently eat raw shellfish
• Laboratory workers and researchers who handle live hepatitis A virus

Immune globulin is primarily used to prevent the disease after exposure to the virus. It is also used to protect travelers to areas with a high incidence of the disease. The prophylactic value of IG is greatest when given early in the incubation period, and protection lasts only a few weeks.

For hepatitis E infection, prevention is dependent upon a clean water supply and improved hygiene and sanitation practices in developing countries. Travelers to countries where hepatitis E is endemic should not assume protection against this virus even if they have been vaccinated against hepatitis A.

Frequent hand-washing with soap and water is key to preventing both types of infection, particularly after bowel movements and before food preparation. Avoiding tap water, food items washed in tap water, and raw, unpeeled fruits and vegetables when traveling is critical to preventing hepatitis A and E infections.