Since 1995, new cases of reported acute hepatitis A have fallen by 88% to 1.5 cases per 100,000 people, the lowest level ever reported since the government began collecting surveillance data more than 40 years ago.

Likewise, since 1990, new cases of hepatitis B have fallen 79% to 1.8 cases per 100,000 people, CDC researchers report surveillance summary included in the March 16th issue of the Morbidity and Mortality Weekly Report.

"The sharp declines in rates of hepatitis A and B are one of the big public health success stories of the last 10 years," Dr. Kevin Fenton, director of CDC's National Center for HIV/AIDS, Viral Hepatitis, STD and TB Prevention, said in a statement.

"The drops in new cases of hepatitis A and hepatitis B," he added, "are evidence that our prevention strategies have been successful, particularly the widespread use of vaccines for hepatitis A and hepatitis B. In order for these declines to continue, our prevention efforts must be sustained."

Cases of hepatitis C have also declined steadily since the late 1980s, CDC reports, but cautions that surveillance for HCV is limited because many individuals do not know they are infected with the virus. The decline in HCV cases is likely due to reductions in high-risk behaviors among injection drug users as well as increased efforts in diagnosis.

Despite the declines, more than 100,000 new cases of viral hepatitis were reported in 2005, the CDC notes. "Although the declines in acute viral hepatitis are promising, the number of new infections remains high particularly among unvaccinated adults," Dr. John Ward, director of CDC's division of viral hepatitis said in a statement. "By vaccinating infants against hepatitis B, we have made great progress in reducing infections in children.

Last year, CDC issued new guidelines to increase vaccination coverage among adults at risk for hepatitis B. "We need to encourage vaccination of adults at high risk for hepatitis B, particularly those with multiple sex partners or whose sex partners are already infected, men who have sex with men, and injection drug users," Dr. Ward said.

"In addition to strengthening our efforts to prevent new cases of viral hepatitis, we must also ensure that people with chronic hepatitis are aware of their infection and know how to protect their health and prevent transmission to others," Dr. Ward added.

MMWR 2007;56:1-24.

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