ABSTRACT
Donors' blood is routinely tested for Hepatitis B surface antigen [HBsAg] in the blood transfusion department of Pakistan Institute of Medical Sciences, Islamabad. Data generated from January 1991 to December 1993 retrospectively analyzed for the HBsAg carrier rate. Out of a total of 20787 samples tested by reverse passive haemagglutination [RPHA] Serodia technique, 582 [2.80%] were found to be positive for the HBsAg, while 610 samples [2.93%] gave non-specific results. All the positive and non-specific tests were again checked by Elisa technique which reduced the positivity rate from 2.8% to 2.3%, thus indicating 114 false positive results. Similarly from the 610 non-specific results only 87 were confirmed positive by Elisa method. It is therefore concluded that out of 20787 healthy blood donors tested 555 [2.67%] were carriers Hepatitis B surface antigen and Elisa technique is more sensitive as compared to Serodia technique for screening blood for HBsAg