High rhesus (Rh(D)) negative frequency and ethnic-group based ABO blood group distribution in Ethiopia

Background: Knowledge of the distribution of ABO-Rh(D) blood groups in a locality is vital for safe blood services. However, the distribution of these blood systems among Ethiopians in general is little explored. This study was, therefore, designed to determine the ABO-Rh(D) blood group distribution among patients attending Gambella hospital, southwestern Ethiopia. Methods: A cross-sectional study was conducted between November and December 2013 (N = 449). The patients were grouped into two broad categories. Those who originally moved from different parts of Ethiopia and currently residing in Gambella are named 'highlanders' (n = 211). The other group consisted of natives (Nilotics) to the locality (n = 238). ABO-Rh(D) blood groups were typed by agglutination, open-slide test method, using commercial antisera (Biotech laboratories Ltd, Ipswich, Suffolk, UK). Results: Overall, majority of the participants (41.20%) had blood type 'O' followed by types 'A' (34.96%), 'B' (20.48%) and 'AB' (3.34%). However, blood type 'A' was the most frequent (44.07%) blood group among the 'highlanders' and 50.42% of Nilotic natives had type 'O'. The proportion of participants devoid of the Rh factor was 19.37%. Conclusions: While the ABO blood group distribution is similar to previous reports, the Rh(D) frequency is much higher than what was reported so far for Ethiopia and continental Africa.