Increasing prevalence of HIV antibody among blood donors monitored over 9 years in one blood bank.

To determine the time trend of HIV infection among non-professional blood donors at the Christian Medical College and Hospital, Vellore, the annual HIV prevalence among them for the years 1993-1997 was compared with that of the previous 5 yr. Since confirmed number of HIV positive blood donors is required for calculation of prevalence, the serum samples which were reactive for HIV 1/2 antibody by ELISA, were confirmed by Western blot. The annual prevalence of HIV antibody gradually increased from 1.6 per 1000 in 1988-1989, to 3.8 per 1000 in 1996-1997. The mean tri-annual prevalences for the years 1988-91, 1991-94 and 1994-97 were 1.3, 2.7 and 3.6 per 1000 respectively, suggesting a slow but steady increase in HIV prevalence over time. Our findings provide an insight into the dynamics of HIV infection in the general population of our country, whom the nonprofessional blood donors at our hospital represent.

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.