- About 15% of people infected with hepatitis A will have recurring symptoms over a 6 to 9 month period.
- Hepatitis A occurs in epidemics (many affected people) within the United States and internationally.
- During epidemics years the number of cases of hepatitis A reached 35,000 in the U.S.
- The number of cases of hepatitis A decreased in the early 1990, when the vaccine (shot) began to be used more commonly.
- One-third of Americans have had hepatitis A at some point of their lives.
- About 30% of people with hepatitis B show no signs or symptoms.
- Chronic (long-term) infection due to hepatitis B occurs in 90% of babies infected at birth.
- Death from chronic liver disease due to hepatitis B occurs in 15 to 25% of infected persons.
- Infections due to hepatitis B declined from 450,000 in the 1980s to about 80,000 in the late 1990s.
- The highest number of cases of hepatitis B occurs in people from 20 to 49 years of age.
- Largest decline of hepatitis B due to vaccination has occurred in children and teenagers.
- About 1.25 million people in the United States have chronic infection of hepatitis B.
- Between 20 and 30% of adult Americans with chronic hepatitis B were infected during childhood.
- About 80% of persons infected with hepatitis C show no signs or symptoms.
- Chronic infection due to hepatitis C occurs among 75% to 85% of infected people.
- Persons infected with hepatitis C have declined from 240,000 in the 1980s to 40,000 in 1998.
- A majority of persons infected with hepatitis C are infected because of drug use.
- About 3.9 million Americans have been infected with hepatitis C.
- Of the total hepatitis C infected Americans, about 2.7 million are chronically infected.