The prevalence of markers for hepatitis B and human immunodeficiency viruses, malarial parasites and microfilaria in blood donors in a large hospital in south India.

Blood donors (35,395) were screened at the CMC Hospital, Vellore, in South India during the 2-year period from July 1986 to June 1988. They were either relatives of patients (referred to as replacement donors) or volunteers. Paid or professional donors were not accepted. Of the replacements 21.5% and of the voluntary donors 9.7% were rejected. Mean donor age was 32.2 years and the commonest blood group was O (39.46%), Rh positive (93.93%). Hepatitis B surface antigen was found in 1.37% and 2.96% of voluntary and replacement donors respectively. Anti-HIV antibodies were found in 1.9/1000 donors. This shows an increasing prevalence of HIV infection in the Indian donor population not reported earlier. The prevalences of malarial parasites and microfilaria in replacement donors were 0.02 and 1.62% respectively. In voluntary donors, malarial parasites were not found and microfilaria were found in only 0.15%. All rejection criteria except low haemoglobin were significantly more frequent among replacement donors than among voluntary donors. In the light of these results, screening of all donor blood for HBsAg and Anti-HIV by the most sensitive techniques and for malarial and filarial parasites in endemic areas is essential.