Hepatitis B on Decline but Many Still at Risk

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Hepatitis B on Decline but Many Still at Risk

Mon Mar 18, 1:30 PM ET

By Jacqueline Stenson



NEW YORK (Reuters Health) - New cases of hepatitis B have decreased substantially in recent years, but the incidence could be reduced even further by widespread programs to vaccinate high-risk adults, according to US health officials.



  

"This (report) is an indication of how successful we've been with our prevention programs and where we need to focus our efforts in the future," study author Miriam J. Alter, an epidemiologist at the Centers for Disease Control and Prevention (news - web sites) (CDC), told Reuters Health.



Hepatitis B is a virus that infects the liver. It is most commonly spread through blood, semen and vaginal secretions. Those at high risk include injection drug users, people who engage in unprotected sex and healthcare workers. Infection, which can lead to cirrhosis and liver cancer, causes as many as 5,000 deaths each year in the United States.



Government researchers at the CDC worked with local public health officials at four US counties--Denver County, Colorado; Pierce County, Washington; Jefferson County, Alabama; and Pinellas County, Florida--to gather detailed information on adults and children infected with hepatitis B from 1982, when the hepatitis B vaccine became available, to 1998. The researchers chose these counties because they are representative of the general population.



Results published in the March 15th issue of the Journal of Infectious Diseases showed that while infection rates fluctuated somewhat until 1987, when they peaked, they declined 76% between 1987 and 1998, from 13.8 cases per 100,000 people to 3.3 cases per 100,000. This decline mirrored a similar drop seen in another national study on hepatitis B infections, the researchers report, but the new study offers more information about risk factors and missed opportunities for prevention.



The greatest decline in hepatitis B cases was seen among those aged 10 to 19 and is likely due to vaccinations, which were recommended for routine use among children starting in 1991 and among adolescents in 1995, the authors note.



Some of the declines among heterosexuals engaging in risky sex--the population most at risk--may have been due to an increase in safe sexual practices or vaccination, most likely among healthcare workers getting immunized, the report indicates.



Sharp drops among injection drug users were more difficult to explain, since few were vaccinated, according to the study authors. One explanation is that needle-exchange programs helped reduce the spread of the virus. Another possibility, they suggest, is that the "reservoir" for the virus--other infected people--shrank due to people dying from AIDS (news - web sites) or being jailed for drug possession.



Declines among gay men from 1982 to 1986 were attributed to increased safe sex practices in response to the AIDS epidemic, though the number of new hepatitis B infections remained fairly static after that time.



The study also found that more than half of infected people interviewed from 1996 to 1998 reported being treated for another sexually transmitted disease (STD) or spending time in jail prior to diagnosis with hepatitis B. As a result, many hepatitis B infections could have been avoided if there were routine vaccinations at both STD clinics and jails, the researchers add.



"Our concern is that more than half of these cases could have been prevented if vaccinations had been given, as is recommended," Alter said. "Our vaccination of high-risk adults is not an effective program in this country. A large part of the problem is that there's no federal funding for adults."



There is federal funding to vaccinate children, she noted.



SOURCE: Journal of Infectious Diseases 2002;185:713-719.