RESUMO
Frequency distribution of blood groups is important as it is used in mod-, ern medicine, genetic research, anthropology, and tracing ancestral relations of humans. The ABO and Rh blood groups are the most important blood groups despite the long list of several other blood groups discovered so far. To study and document the frequency of ABO and Rh [D] blood groups in three ethnic groups of Silte Zone, Ethiopia. ABO and Rh [D] typing was carried out during 2012 and a total of 441 students from both genders were randomly selected from Silte Secondary and Preparatory School, SNNPR, Ethiopia. Finger prick blood samples from both genders were tested for ABO and Rh [D] blood groups by the open slide test method. A drop of each of the antisera, anti-A, anti-B and anti-D was added and mixed with each blood sample and rocked gently for 60 s to observe agglutination. The blood group CT was predominant [36.73%, 40.14%, 46.26% in Sodo, Silte and Meskan ethnic groups, respectively] in all the Rh positive subjects whereas blood group [A] was predominant [5.4%] in the Rh negative subjects only in the Sodo ethnic group among the three ethnic groups. The percentage of Rh [D] positive and negative subjects was 91.16%, 93.19%, 91.84% and 8.84%, 6.81%, 8.16% in Sodo, Silte and Meskan ethnic groups, respectively. The frequency of ABO blood groups in both Rh positive and negative subjects among the three ethnic groups of the Silte Zone, Ethiopia was O > A > B > AB, except in the Sodo ethnic group where the blood group A was the commonest among Rh negative subjects