DECLINE IN HEPATITIS-B INFECTION IN SICKLE-CELL-ANEMIA AND BETA-THALASSEMIA MAJOR

Seventy five Saudi children, 55 with sickle cell anaemia and 20 with b eta thalassaemia major, who were negative for all hepatitis B virus (H BV) markers five years ago were recently investigated for exposure to HBV and hepatitis C virus (HCV) infection. Of the 55 patients with sic kle cell anaemia and 20 with beta thalassaemia major, 20 and five pati ents respectively had been vaccinated against HBV earlier and all of t hem still had protective antibody (anti-HBs 42-96 IU) 3-5 years after vaccination and there was no vaccine failure. Among the non-vaccinated children the exposure rates to HBV were 14.3% among those with sickle cell anaemia and 26.7% among those with beta thalassaemia and this wa s not statistically significant when compared with the exposure rate t o HBV among the general paediatric population (20.1%). Anti-HCV positi vity among those with beta thalassaemia major and sickle cell anaemia was 70% and 18.2%, respectively, and this was significantly higher tha n anti-HCV positivity among the control group (0.8%). Anti-HCV positiv ity was directly related to the amount of blood transfused and to the duration of transfusion. The results of the study show that although t he exposure rates to HBV among patients with sickle cell anaemia and b eta thalassaemia major were not significantly different than that amon g the general paediatric population, infection with HBV still takes pl ace among non-vaccinated patients despite strict precautionary measure s taken. Hence early vaccination against HBV would probably be the onl y effective way of controlling HBV infection. For HCV infection, and b ecause a vaccine against HCV is still not available, preventive measur es such as blood screening for anti-HCV before transfusion and stringe nt infection control measures are crucial steps to be implemented for the control of spread of HCV among these groups of patients.