Frequency of appearance and prevention of hepatitis A infections in hemophilic children in Poland

Purpose The main aim of this study was to define the incidence of anti-HAV in hemophilic children not previously treated with blood products and to es timate the immunologic response in seronegative children after vaccination against the hepatitis A virus. Patients and methods Twenty-seven children with hemophilia A, who had never been treated with blood products, were tested for the presence of anti-HAV . Anti-HAV antibody investigations were carried out by the immunoenzymatic method using the Enzymun anti-HAV test (Boeringer Mannheim, Germany). 'Havr ix' vaccine was administered to 15 of 16 seronegative children (mean age 28 .8 +/- 8.3 months). Results Anti-HAV antibodies were found in 11 of 27 patients (40%). It is po ssible that children under 12 months received the antibody from their mothe rs. In the group of children over 12 months old anti-HAV antibodies were di scovered in 6 of 19 patients. After vaccination the presence of anti-HAV an tibodies was observed in a preventive titre in all children. Conclusions Due to the high incidence of anti-HAV antibody occurrence, as w ell as the efficacy and safety of the anti-HAV vaccine, we suggest anti-HAV vaccination at an early stage of treatment.