Distribution of ABO and Rh-D blood groups among blood donors in a tertiary care centre in South India

The distribution of ABO and Rh-D blood groups was studied among 150,536 blood donors screened at the Dr John Scudder Memorial Blood Bank, Christian Medical College Hospital, Vellore, over a period of 11 years (April 1988 to March 1999).The most common blood group was found to be group O [58,330 (38.75%)], followed by group B [49,202 (32.69%)], and group A [28,372 (18.85%)]. The least common blood group was AB group [7,930 (5.27%)]. A2 or A2B groups were found in 3.01% and 1.43% of donors, respectively.The prevalence of Rh-D negative group was found in 8,225 (5.47%) donors. Bombay group (H negative non-secretor, genotype hh phenotype Oh) was found in six donors (0.004%). Although the incidence of Rh-D negative group was identical to previously published data from North India, the most common blood group was O group in our study as opposed to B group.