Hepatitis A

Ingestion of something contaminated with the stool of an infected person, usually because of poor hygiene or inadequate sanitation (called the fecal-oral route).

Usually no symptoms in young children

Usually in older children and adults, typical symptoms of acute hepatitis (poor appetite, nausea, vomiting, and often jaundice)

Usually complete recovery

Does not become chronic

Use of good hygiene when handling food and avoidance of contaminated water

Vaccination against hepatitis A for all children (see figure Routine Vaccinations for Infants, Children, and Adolescents) and for adults likely to be exposed to the infection

If people are exposed to hepatitis A, hepatitis A vaccine or standard immune globulin*

Hepatitis B

Less easily transmitted than hepatitis A

Contact with blood and other body fluids (such as semen, vaginal fluids, or saliva)—as occurs during the following:

• Sharing of unsterilized needles to inject illicit drugs

• Reuse of unsterilized needles to apply tattoos

• Sexual activity

• Birth of a baby†

Generally more serious than hepatitis A and occasionally fatal

More severe symptoms when people with hepatitis B also have hepatitis D

Joint pains and itchy red hives on the skin (wheals) in addition to typical symptoms of acute hepatitis

Can become chronic, with increased risk of liver cancer

Avoidance of high-risk behavior, such as sharing needles to inject drugs and having several sex partners

Vaccination against hepatitis B for all children (starting at birth—see figure Routine Vaccinations for Infants, Children, and Adolescents) and for people likely to be exposed to the infection

Hepatitis C

Contact with blood and other body fluids (such as semen, vaginal fluids, or saliva)—as occurs during the following:

• Sharing of unsterilized needles to inject illicit drugs

• Reuse of unsterilized needles to apply tattoos

• Sexual activity (not commonly)

• Birth of a baby† (not commonly)

At first, usually mild or no symptoms but sometimes alternating between mild and more severe symptoms

Becomes chronic in about 75% of people, with increased risk of severe scarring of the liver (cirrhosis) and liver cancer, but usually only if cirrhosis has developed first

Avoidance of high-risk behavior, such as sharing needles to inject drugs and getting tattoos and body piercings

No vaccine currently available

Hepatitis D

Contact with blood and other body fluids (such as semen, vaginal fluids, or saliva)—as occurs during the following:

• Sharing of unsterilized needles to inject illicit drugs

• Reuse of unsterilized needles to apply tattoos

• Sexual activity

Occurs only as a coinfection with hepatitis B and usually makes the hepatitis B infection more severe

Same as for hepatitis B:

• Avoidance of high-risk behavior

• Vaccination against hepatitis B

Hepatitis E

Ingestion of something contaminated with the stool of an infected person, usually because of poor hygiene or inadequate sanitation (called the fecal-oral route)

Occasionally consumption of meat from an infected animal

Severe symptoms, especially in pregnant women

Does not usually become chronic

Vaccination against hepatitis E (currently, available only in China)