Volume 1, Number 2
Hepatitis A Cases Shelby County, Tennessee 1994-1196 |
say experts
(Washington) Epidemiologists from CDC say that the U.S. is making progress in the control of hepatitis B, but that the overall trend in incidence is difficult to evaluate because of under-reporting from the states. Their report came at a workshop held during the National Immunization Conference on April 10. "Hepatitis B vaccine coverage rates in health care workers (HCWs) are high, and, in that group, hepatitis B is almost a disease of the past," said Dr. Frank J. Mahoney, Chief of the Hepatitis Prevention Unit at CDC, who moderated the workshop. "Furthermore, the integration of hepatitis B vaccine into infant vaccination schedules in Alaskan Natives and Pacific Islander communities has resulted in a dramatic decrease in the prevalence of chronic HBV infection among children who have been born since the programs implementation. Other programs aimed at perinatal hepatitis B transmission are also having a major impact. The challenge now is to vaccinate teenagers and young adults," he said.
Elizabeth Zell, a CDC statistician, presented data from the National Immunization Survey, which monitors vaccine coverage in children ages 19 to 35 months. For the first quarter of 1995, the up-to-date coverage rate for hepatitis B vaccination had risen to 56.4%, indicating good progress in infant vaccination. However, the rate varied greatly from state to state. The lowest coverage rates (0-20%) were in South Dakota, Wyoming, Mississippi, and West Virginia. The highest rates (60%+) were in Massachusetts, New Jersey, and South Carolina. Coverage also varied by race/ethnicity, with white non-Hispanics at 55.9%, Hispanics at 63.1%, black non-Hispanics at 49.2%, and Asians at 74.6%. Encouragingly, younger cohorts had higher coverage levels than older cohorts.
Dr. Susan Goldstein, a medical epidemiologist at the CDC Hepatitis Branch, showed surveillance data from the CDC Sentinel County Study, which monitors the epidemiology of acute viral hepatitis in four U.S. counties. Overall, the incidence of hepatitis B decreased by 57% from 1989 to 1993, but then rose slightly in 1994-95. The recent rise occurred in young adults, in non-white racial/ethnic groups, and in three high-risk groups: homosexuals, intravenous drug abusers, and especially in heterosexuals. The rise is not traceable to reporting artifact, since the Sentinel Counties surveillance system has remained unchanged. Dr. Goldstein said that the data most likely reflect an increase in risky sexual and drug-abusing behavior. They also show how difficult it is to deliver hepatitis B vaccine to non-HCW high-risk groups.
National data from NNDSS, the CDC's national surveillance system, show a steady decline in hepatitis B incidence. The current rate is about one-half the rate in 1985. "In the last few years, total case counts for hepatitis B have continued to decline in the United States," said Dr. Miriam J. Alter, Epidemiology Chief at the CDC Hepatitis Branch in an interview, "but we think this could be an under-reporting artifact. Many states have cut their surveillance activities. As a result, it is very difficult to evaluate national data."
Some state health departments reported hundreds of cases annually in the early 1990s, but now report only a handful. This almost certainly indicates an abandonment of hepatitis B surveillance. In many such states, funding cuts have prompted cutbacks in disease control activities.
Dr. Mahoney says that future hepatitis B control efforts need to concentrate on adolescents, while also increasing infant coverage rates. ACIP recognized this last year when it officially recommended hepatitis B vaccination for all 11-12 year-olds. Dr. Mahoney said "we need to work hard toward getting adolescents vaccinated so they won't get hepatitis B later in life."