The three most common forms of acute viral hepatitis in the United States -- hepatitis A, B and C -- declined dramatically between 1995 and 2005, with hepatitis A and B at the lowest levels ever recorded since the government began collecting surveillance data more than 40 years ago, according to the Centers for Disease Control and Prevention (CDC).
Hepatitis B and C are diseases that can lead to liver cancer and death.
The main factor behind the declines in new cases of hepatitis A and B were the availability of vaccines and strong federally supported immunization programs.Â Â Declines in new cases of hepatitis A were greater among children in the 17 states where routine vaccination of children has been recommended since 1999.Â The declines in hepatitis B were greatest among children and teens age 15 and younger, likely the result of high vaccination coverage in this age group.Â The CDC recommends three doses of hepatitis B vaccine beginning at birth.
Declines in reported new cases of hepatitis C were likely due to reductions in high-risk behaviors among injection drug users, as well as efforts to diagnose individuals infected with hepatitis C and the promotion of health behaviors to reduce person-to-person transmission of the virus.
Since 1995, new cases of reported acute hepatitis A have declined by 88 percent, to an incidence of 1.5 per 100,000 population, the lowest rate ever reported, according to the Morbidity and Mortality Weekly Report (MMWR) Surveillance Summary, "Surveillance for Acute Viral Hepatitis - United States, 2005."Â Â
"The sharp declines in rates of hepatitis A and B are one of the big public health success stories of the last 10 years.Â The drops in new cases of hepatitis A and hepatitis B 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," said Dr. Kevin Fenton, director of CDC's NationalCenter for HIV/AIDS, Viral Hepatitis, STD and TB Prevention.
The CDC recommends that all children 12 months to 23 months be vaccinated against hepatitis A.Â In addition, hepatitis A vaccine is also recommended for persons at risk for infection, including international travelers, men who have sex with men, injection and non-injection drug users, and children living in communities with high rates of the disease.
The reported cases of acute hepatitis B also dropped to the lowest rate ever recorded in 2005 (1.8 per 100,000), a decline of 79 percent from
1990.Â Â In addition to the declines noted in children, hepatitis B rates
also declined among adults but remained highest among those 25 to 44 years of age and among people with behavioral risk factors such as high-risk sexual activity and injection drug use.Â
Cases of hepatitis C have also declined steadily since the late 1980s. However, this trend should be viewed with caution since surveillance for acute hepatitis C is limited because many individuals do not immediately develop symptoms and do not know they are infected with the virus.
Despite the declines, more than 100,000 new cases of viral hepatitis were reported in 2005.Â "Although the declines in acute viral hepatitis are promising, the number of new infections remains high particularly among unvaccinated adults," said Dr. John Ward, director of CDC's division of viral hepatitis.Â Â "By vaccinating infants against hepatitis
B, we have made great progress in reducing infections in children.Â
In 2006, CDC issued new guidelines to increase vaccination coverage among adults at risk for hepatitis B.Â "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," Ward said.
More than 4.5 million Americans are living with chronic hepatitis B and hepatitis C and are at serious risk for liver cirrhosis and cancer.
"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," Ward added.