Summer 1997 Volume 2, Number 2		Prevention of perinatal HBV infection: progress and problems discussed at National Immunization Conference (Detroit) Prevention of perinatal hepatitis B infection was the topic of discussion at the National Immunization Conference, held in Detroit in May. Nicole Smith, MPH, MPP, a Fellow at the Association of Schools of Public Health working at the CDC Hepatitis Branch, reviewed progress toward the agency's goal of reducing perinatal hepatitis B virus (HBV) transmission by 80% - from 9,500 to 1,900 infections per year - by the year 2000. CDC adopted the goal in 1995 in collaboration with state-based immunization staff and the Council of State and Territorial Epidemiologists. Ms. Smith said that CDC's methods for attaining the goal remain unchanged: hepatitis B surface antigen (HBsAg) screening of all pregnant women, identification and reporting of HBsAg-seropositive women, immunoprophylaxis of newborns at birth, and completion of the vaccination series by 6 months of age. Success in screening pregnant women for HBsAg The 1995 CDC goals included an objective that, by the year 2000, 90% of pregnant women would be screened for HBsAg prior to delivery. This objective may already have been reached in some parts of the United States. In a review of almost 4,000 records conducted by CDC four years ago, 84% of women giving birth had HBsAg results entered in their hospital records. Other studies done in New York, Kansas, California, and other states have shown screening rates as high as 96%. In many other states, however, the screening rate has not been formally evaluated. Despite this success, thousands of women are still not being screened. The question is: why? Studies have cited hospital factors, such as the lack of policies for documenting prenatal screening or for testing women whose HBsAg status is unknown at the time of admission. In most studies, documentation of maternal HBsAg status was more likely to be missing in rural and small hospitals than in large urban facilities. Studies also cite maternal characteristics, such as absent or late prenatal care, adverse insurance status, non-white race and low education level. Mandatory screening laws seem to help. Hospitals located in states that mandate maternal HBsAg screening are more likely to have screening policies. One of the goals adopted by CDC in 1995 was that, by 1998, all 50 states should have screening laws. But, according to Ms. Smith, only about 13 states have enacted such laws, and, with 1998 only a few months away, this goal will not be met. Identifying and tracking infants born to HBsAg-seropositive women CDC is able to estimate the number of births to HBsAg-seropositive women in each state using HBsAg prevalence data from the National Health and Nutrition Examination Survey (NHANES III). The agency compares these estimates to the actual number of women identified in each state to calculate the state's "performance" in identifying and tracking infants born to seropositive mothers. Ms. Smith said that, using this method, only about 40% of babies born to HBsAg seropositive mothers in the U.S. are being identified currently. There is a long way to go to reach the 90% goal in the year 2000. Many states have done very well in identifying these neonates (see map on page 6). Colorado, Kentucky, Louisiana, Massachusetts, Michigan, Minnesota, Mississippi, Montana, Rhode Island and Wisconsin have all achieved identification rates of 100% of the minimum CDC expected. Other states have not done as well. The highest identification rates are achieved in places where a computerized system exists to identify and track pregnant women receiving services from private providers and in areas where there are established hospital reporting systems for births to HBsAg-seropositive women, Ms. Smith said. Identification rates are also high in places that require the maternal HBsAg status to be entered on the newborn routine metabolic screening form or on the information submitted for the birth certificate. These requirements steadily remind providers to check maternal serologic status and act on the results. Immunoprophylaxis and vaccination The ultimate goal of screening and itentifying babies born to HBsAg seropositive women is to interrupt transmission through immunoprophylaxis with hepatitis B immune globulin (HBIG) and vaccine beginning at birth. An infant who is born to an HBsAg-seropositive mother and who does not receive prophylaxis faces a 90% HBV infection risk, and a further 90% risk of becoming chronically infected with the virus. CDC's year 2000 goal includes an objective that 90% of infants born to HBsAg-seropositive women will receive HBIG and vaccine at birth, and that 90% will receive the remaining two doses of vaccine by 6-8 months of age. In her presentation, Ms. Smith said that inoculation and vaccination rates for newborns of known HBsAg-seropositive mothers already exceed CDC's 90% objective. But rates are less than 50% for infants born to mothers with unknown HBsAg status. Furthermore, although a high proportion of U.S. infants receive immunoprophylaxis at birth, more than 30% fail to complete the three-dose vaccine series by 6-8 months of age and more than 75% of the identified infants do not receive recommended post-vaccination serologic testing. Key issues in preventing perinatal HBV transmission If we are to reach our year 2000 disease reduction goal, Ms. Smith said, we must strengthen each step in the chain of events leading to full immunoprophylaxis and vaccination of infants born to HBsAg-seropositive mothers. Hospitals must ensure that HBsAg screening occurs routinely during prenatal care, or at the time of admission if it was not done prenatally. To promote this, all states should adopt legislation requiring screening of all pregnant women. It is crucial, she said, to maintain the chain of communication of maternal HBsAg test results. Results must be communicated from the prenatal provider to the mother and to the hospital, from the labor and delivery staff to the nursery staff, and from the hospital staff to the well-child provider. Ms. Smith emphasized that infants born to HBsAg-seropositive mothers or to mothers with unknown HBsAg status must receive proper prophylaxis. Information about an infant's vaccination status must be communicated from the hospital staff to the well-child provider. In addition, Ms. Smith said, to encourage reporting of all births to HBsAg-seropositive women, maternal HBsAg status should be recorded on the newborn metabolic screening cards. To be sure that identified infants receive the recommended immunoprophylaxis, the vaccination and post-vaccination serologic status of all infants born to HBsAg-seropositive mothers should be tracked using a computerized system. Progress in the states Mr. Les Burd, Hepatitis Coordinator at the California Department of Health Services, presented a recent survey of prenatal hepatitis B screening practices in his state. HBsAg screening and reporting has been required in California since 1991. The survey reviewed records on 5,414 women who gave birth. Of these, 34 (0.6%) were HBsAg seropositive. Of the 34 infants born to these infected mothers, all got HBIG and hepatitis B vaccine in the correct dose. Eighty-five percent completed the three dose series of vaccine. However, of infants born to mothers whose HBsAg status was unknown at the time of delivery, only 19.5% were treated appropriately. Mr. Burd and his group also surveyed hospitals in California for their policies on perinatal screening and prophylaxis for hepatitis B. Of the respondents, 92.6% had a policy for ordering HBsAg when the HBsAg status of the mother was unknown at the time of delivery. Louise Bell Paushter, of the Massachusetts Hepatitis B Prevention Project, presented a review of hospital records conducted in Massachusetts. Since 1993, the state's hospital licensure regulations have required that the maternal HBsAg results be documented in both the mother's and the infant's hospital record. The review included a random sample of births in Massachusetts during the first six months of 1995. Of 157 maternal records reviewed, 98.1% had documentation of the HBsAg test result. Of these, 97% had been tested prenatally and 2% were tested in the hospital at delivery. Of the 144 newborn records reviewed, 91.7% had documentation of the maternal HBsAg test result. Eighty-eight percent of newborns received the first dose of hepatitis B vaccine in the hospital. Of the 18 infants who did not receive vaccine in the hospital, two had documentation of parental refusal and two were ineligible for the vaccine because of prematurity and low weight. The Massachusetts survey also looked at whether the correct doses of vaccine and HBIG were given. Of 138 infants who received hepatitis B vaccine, 61% had documentation of the manufacturer and of the correct dose of vaccine. Four percent had documentation that the wrong dose of vaccine was given. The Massachusetts researchers noticed that standing orders for vaccine and HBIG were often written incorrectly. For example, hepatitis B vaccine dosages were sometimes written in milliliters instead of micrograms, or HBIG was ordered if the maternal HBsAg status was unknown. The authors said that, although Massachusetts is doing well in regard to perinatal hepatitis B prevention, there is much need for improvement. In the state, up to 1,550 pregnant women are not being screened annually and up to 9,800 infants do not receive their first dose of hepatitis B vaccine in the hospital. Inadequate documentation and incorrect dosing happen too often.The authors said that obstetricians should review their prenatal worksheets to ensure that there is a space for documenting the dates of prenatal lab tests.