Analysis of a pregnancy-screening and neonatal-immunization program for hepatitis B in Hamilton, Ontario, Canada, 1977-1988.

During the 12 years from January, 1977, to December, 1988, the Hamilton Centre of the Canadian Red Cross Society (CRCS) Blood Transfusion Service screened 98,712 pregnant patients for hepatitis B surface antigen (HBsAg) and identified 120 positives (0.12%). The number of positives ranged from six to 16 per year. We were able to trace and enroll 65 mothers (54%) and 96 of their children in the follow-up study. The majority of the women were between 20 and 30 years of age (95.4%) and married (86%), and about one-half were employed outside the home. Sixty-five percent were white and 34% Asian, and 20 countries were listed as their places of origin. Hepatitis B immune globulin (HBIG) was available for neonatal immunization since 1977 and combined with vaccine since 1982. Of the 96 candidates for HBIG, 60 (63%) received HBIG within 24 hr, one after 3 months, four unknown, and 31 did not receive it. Of the 56 candidates for vaccination from 1982 to 1989, 26 (46%) received three doses, seven had two doses, eight had one dose, one was unknown, and 14 had none. HBsAg tests were performed on 69 children (71.8%) and anti-HBs on 61 (63.5%). Four of the children are HBsAg positive, 31 have anti-HBs, and 31 have no detectable antibodies. All four HBsAg positives had not received vaccine, and only one had received HBIG. Of the children positive for hepatitis B surface antibodies, five had received no immunization and therefore had been subclinically infected.(ABSTRACT TRUNCATED AT 250 WORDS)