Hepatitis A The Centers for Disease Control and Prevention (CDC) estimate that there are around 6,700 new hepatitis A infections each year in the United States. Overall, the number of U.S. cases has declined during the past 20 years — largely due to immunization — but outbreaks do sometimes occur. Hepatitis A usually transmits through contaminated food or water. It is common in many countries, especially those that do not have effective sanitation systems.