IMMUNIZATION AGAINST HEPATITIS-B VIRAL-INFECTION - A STUDY OF SOUTH-AFRICAN ANESTHESIOLOGISTS

Introduction. The practice of anaesthesia involves exposure to blood o r bloodstained secretions which may be contaminated with transmissible pathogens including the hepatitis B virus (HBV). This study was under taken to assess the impact of freely available hepatitis B vaccine and applications of universal precautions against blood exposure on the u ptake of immunisation and prevalence of HBV markers in South Africa an aesthesiologists. Methods. Anaesthesiologists from the Department of A naesthesia of the University of Natal and those attending a continuing medical education course in Cape Town in March 1993 participated in t he study. Each participant completed a questionnaire giving details of previous exposure to HBV, immunisation status and details of immunisa tion. Blood samples were obtained on a voluntary basis for determinati on of HBV serology. Results. One hundred and twenty-one anaesthesiolog ists participated in the study; 36 were unimmunised, of whom 18 (50%) were seropositive for HBV markers. More experienced anaesthesiologists (> 10 years) tended both not to be immunised and to be seropositive, indicating previous exposure to HBV. Eighty-five participants were imm unised. Intradermal immunisation caused significantly less seroconvers ion than the intramuscular route (35% v. 81%; P < 0,05). Of 7 non-resp onders to intradermal immunisation, 5 responded to a single intramuscu lar booster injection. Discussion. Exposure to HBV is common in anaest hetic practice, as evinced by the 50% seropositivity in unimmunised an aesthesiologists, which means that routine serological testing before immunisation is warranted. Intramuscular immunisation provides the bes t protection against HBV. Post-immunisation serological testing should be performed to demonstrate an adequate antibody response. The intrad ermal route may save cost with similar efficacy if combined with post- immunisation testing and a single intramuscular booster injection for non-responders.