Geographical and ethnical distribution of HBs antigen subtypes in Mauritania

A survey conducted in sera from 515 black and 499 white individuals living in 8 villages of Mauritania showed an HBs Ag prevalence of 15.7%. Two main subtypes, ayw2 (34.7%) and ayw4 (63%), were found in this country which is a junction area between North and West Africa and where 2 ethnic groups are living close one to the other but with very rare cross-breeding. ayw2 was more prevalent in the driest part of the country (North) and ayw4 in the South. Analysis of the subtype distribution in each village indicates that there is no relationship between HBs Ag subtype and ethnic groups, but there is a correlation between HBs Ag subtype and the geographical location of the villages.