HIGH PREVALENCE OF HBV INFECTIVITY IN BLOOD-DONORS DETECTED BY THE DOT-BLOT HYBRIDIZATION ASSAY

Hepatitis B virus (HBV) continues to be a significant cause for post-t ransfusion hepatitis in India, in spite of the introduction of compuls ory hepatitis B surface antigen (HBsAg) screening. To understand the t rue HBV-infective pool in the blood donor population, HBV DNA was dete cted by a P-32-labelled dot blot hybridisation assay in 605 donor unit s that were negative for HBsAg by a third-generation Elisa. Serum alan ine aminotransferase (ALT) was estimated in all these samples and corr elated with DNA positivity. The frequency of HBV DNA positivity in HBs Ag-negative units was very high (9.91%) and correlated well with the e levation in ALT (p<0.00005). However, the frequency of elevated ALT wa s high (11.9%), using the locally determined upper limit of normal, an d half of the DNA-positive samples had a normal ALT. Thus, ALT is a po or surrogate marker for HBV infectivity and efforts should be made to apply DNA detection systems in blood banks.