Report from Austin: Special Coverage of the 1998 National Hepatitis Coordinator Conference

http://www.hepatitiscontrolreport.com/vol/v3n11.html

 
    Report from Austin:
Special Coverage of the 1998 National Hepatitis Coordinator Conference

Editor's Note: The annual CDC Hepatitis Coordinator Conference is the largest meeting in the U.S. devoted to the control of viral hepatitis. The1998 Conference was held on May 19-21 in Austin, Texas. Attendees included hepatitis coordinators from all 50 states, health department personnel, staff from the CDC Hepatitis Branch and National Immunization Program, representatives from advocacy groups, and vaccine manufacturers. The theme of this year's meeting was "Achieving the Goal of Hepatitis B Elimination." Here are the highlights.

Failure to vaccinate high-risk adults blocks hepatitis B elimination in U.S., says CDC

The vaccination of high-risk adults now stands as the biggest obstacle to eliminating hepatitis B transmission in the United States, according to Dr. Harold S. Margolis, Chief of the CDC Hepatitis Branch.

Margolis told attendees at the annual Hepatitis Coordinator Conference that the nation is "doing well" in achieving three main components of the U.S. Public Health Service (PHS) hepatitis B elimination plan: routine vaccination of all newborns, catch-up vaccination of high-risk children, and routine vaccination of adolescents. However, he said, the fourth component, vaccination of high-risk adults, has been a frustrating "legacy of missed opportunities."

The PHS hepatitis B elimination plan was developed by CDC in the late 1980s and officially adopted by the Immunization Practices Advisory Committee (ACIP) in November 1991 (MMWR 1991;40(RR-13):1-19).

Margolis's remarks reflect a growing frustration within CDC and state health departments about the lack of progress in vaccinating adults at high risk for hepatitis B, such as injecting drug users, men who have sex with men, and household or sexual contacts of persons with chronic hepatitis B virus (HBV) infection. Despite official recommendations dating back to 1982, vaccination in these groups has been extremely slow.

Health care professionals miss many opportunities to vaccinate high-risk adults. In a 1996 CDC survey of adult hepatitis B cases, 27% had been treated for a sexually-transmitted disease (STD), 20% had been in prison, 10% had a history of sexual contact with a chronically infected patient, and 8% had a history of household contact with an HBV-infected person. In all, 58% of adult hepatitis B cases had histories that should have triggered vaccination. If these missed opportunities could be eliminated, Margolis said, a majority of the adult at-risk population could be immunized.

Another problem is bureaucratic tunnel vision. For example, in the late 1980s, researchers established a clear epidemiologic link between the risk for STDs and the risk for hepatitis B. ACIP recommended vaccination for STD patients in 1991. But, in a 1997 survey cited by Margolis, only 47% of managers of federally-funded STD projects thought that hepatitis B vaccination was the responsibility of their program, and only 24% offered the vaccine (CDC, unpublished data).

Other barriers to high-risk adult vaccination include the cost of vaccine and the lack of insurance coverage. Margolis pointed out that, of the "big three" vaccine-preventable diseases of adults (influenza, pneumococcal disease, and hepatitis B), only hepatitis B vaccine is not covered by public or private insurance. Moreover, he said, when financial barriers are removed, vaccination of adults does succeed. For example, 70% percent of health care workers at occupational risk for hepatitis B have been been vaccinated, largely because of the 1992 OSHA regulations requiring employers to provide vaccine to this group (Mahoney FJ, et al. Progress towards the elimination of hepatitis B virus transmission in the United States. Viral Hepatitis 1997; 3: 105-19).

But vaccination rates for other high-risk adults remain low. In a California survey, only 3% of homosexual men had evidence of hepatitis B vaccination (MMWR 1996;45:215-7), and successful vaccination programs for injecting drug users are almost non-existent.

Margolis stressed that hepatitis B transmission cannot be eliminated, at least in the near term, without effective vaccination of adult high-risk groups. Adults transmit HBV directly to other adults. Immunizing children and adolescents will eventually slow adult transmission (provided that vaccine immunity does not wane too far), but it will take a generation for this to occur.

Margolis does not want to wait that long. "Unless we can find a way to vaccinate high-risk adults, countries such as Taiwan will eliminate HBV transmission before the United States does," he said. "Yes, vaccinating high-risk adults is complicated, but we must find a way to accomplish it."

Revisiting surveillance:
CDC will launch quarterly reports in 1998

CDC and the states are continuing to discuss ways in which surveillance for viral hepatitis can be improved, according to staff from the CDC Hepatitis Branch and the Council of State and Territorial Epidemiologists (CSTE) (see HCR, Summer 1997 issue). CSTE has contracted with an epidemiologist, Dr. AnneMarie Wasley, to help the Branch devise a new hepatitis surveillance system, one that will meet future public health needs.

At the Conference, Wasley said that the new system should be sensitive enough to detect relatively small changes in hepatitis incidence. It should also facilitate investigation of cases and provide useful data for directing and evaluating prevention programs.

The current system does not fill those needs optimally, she said. Several states do not even participate in CDC's most detailed surveillance system, the Viral Hepatitis Surveillance Program (VHSP). In a recent survey of state health departments, Wasley found that the main reason for low participation in VHSP is lack of personnel. With only one or two people per state doing hepatitis surveillance, there are not sufficient personnel to collect all the data requested on the VHSP form.

To improve the quality and completeness of CDC surveillance, the agency is revising the VHSP form and upgrading its system for recording incoming data, both electronic and paper. To improve states' access to the information (at this writing, the most recent CDC Hepatitis Surveillance Report was issued in April 1996), the agency will launch a new quarterly surveillance report. The first report, due out soon, will cover the first quarter of 1998.

Another important issue is surveillance for chronic HBV infection. Currently, CDC collects data only on the incidence of acute disease, which are not very useful for assessing trends in chronic infection. The NHANES II and NHANES III seroprevalence surveys provided some trend data, most recently in 1988-94, but the samples were too small to assess prevalence in high-risk groups and in smaller geographic areas. The next survey, NHANES IV, will be conducted in 1998-2000, but Wasley believes that dedicated surveys in high-risk groups will be needed to truly assess chronic infection in those groups.

CDC is also considering the establishment of a surveillance system dedicated to perinatal hepatitis B. The agency will pilot such a system soon in several states. The dedicated system will help answer some very important questions, such as the rate of vaccine failures in infants, vaccine escape mutants, and waning vaccine-induced immunity.

The State of Wisconsin piloted a registry for chronic HBV infections in 1996. Marjorie Hurie, a nurse with the Wisconsin Department of Health, presented data from the pilot at the Conference. The registry received reports from laboratories, private providers, blood and plasma centers, and out-of-state sources, and attempted to follow up persons identified as hepatitis B surface antigen (HBsAg) positive through questionnaires, chart reviews and interviews. Follow-up was successful in 91% of positive HBsAg tests overall and in 100% of such tests in pregnant women. The pilot registry found that 72% of contacts of HBsAg-seropositive pregnant women were properly vaccinated, versus 55% of contacts of non-pregnant persons.

"We have a two-tiered system of follow-up for hepatitis B," said Hurie. "Follow up for pregnant women is much better, in part because it is funded. There is no special funding for follow-up of non-pregnant people."

San Antonio hepatitis A vaccination program cites low coverage rates

In February 1997, San Antonio, Texas became the first jurisdiction in the U.S. to offer routine vaccination against hepatitis A to schoolchildren (see HCR Winter 1996-97 issue). The program, a five-year demonstration project led by San Antonio Health Director Dr. Fernando Guerra, has offered hepatitis A vaccination for all children ages 3-9 in 46 schools and 31 day care centers and Headstart centers located in the central city, where hepatitis A rates have been high for many years (30-50 per 100,000 person-years). At the Conference, Linn Watson, hepatitis coordinator and director of the San Antonio project, presented the results of the project to date.

The San Antonio program is purely voluntary ‚ in order for children to receive the vaccine, parents must return a consent form distributed by teachers in the targeted schools. Realizing that compliance with voluntary vaccination programs is often low, Watson and her staff promoted the project with parties, media coverage, and educational presentations for parents. The project was developed in close consultation with medical staff from the targeted area.

In the first year, the two-dose completion rate in elementary schools was 43%. In the second year, the one-dose completion rate was 38% (the second dose was not yet due at the time of analysis). The one-dose completion rates for Headstart and day care centers were somewhat higher, at 71% and 51%, respectively.

Watson said that it is too early to determine the impact of the vaccination program on hepatitis A incidence in the targeted area (although preliminary data show a decrease in hepatitis A incidence in the vaccinated group). However, the coverage rates attained by the program are probably lower than the rate needed to interrupt transmission. In a well-known study by McMahon in Alaska, vaccine coverage of 79% was successful in stopping an outbreak, but coverage of 49% was not (McMahon BJ, et al. Arch Pediatr Adolesc Med 1996;150:733-39.) Likewise, in the large hepatitis A vaccine intervention in Memphis, Tennessee in 1995, a vaccine coverage rate of 54% in high-incidence areas did not definitively affect transmission (Craig AS, et al. Clinical Infectious Diseases , in press).

Watson pointed out that the low coverage rates attained by the program occurred despite strong promotional and educational efforts by Health District and school personnel.

ALL INFORMATION, DATA, AND MATERIAL CONTAINED, PRESENTED, OR PROVIDED HERE IS FOR GENERAL INFORMATION PURPOSES ONLY AND IS NOT TO BE CONSTRUED AS REFLECTING THE KNOWLEDGE OR OPINIONS OF THE PUBLISHER, AND IS NOT TO BE CONSTRUED OR INTENDED AS PROVIDING MEDICAL OR LEGAL ADVICE.  THE DECISION WHETHER OR NOT TO VACCINATE IS AN IMPORTANT AND COMPLEX ISSUE AND SHOULD BE MADE BY YOU, AND YOU ALONE, IN CONSULTATION WITH YOUR HEALTH CARE PROVIDER.