Where are the different subtypes and CRFs found?
The HIV-1 subtypes and CRFs are very unevenly distributed throughout the world, with the most widespread being subtypes B and C. Subtype C is largely predominant in southern and eastern Africa, India and Nepal. It has caused the world’s worst HIV epidemics and is responsible for around half of all infections. Historically, subtype B has been the most common subtype/CRF in Europe, the Americas, Japan and Australia. Although this remains the case, other subtypes are becoming more frequent and now account for at least 25% of new infections in Europe. Subtype A and CRF A/G predominate in west and central Africa, with subtype A possibly also causing much of the Russian epidemic4 . Subtype D is generally limited to east and central Africa; A/E is prevalent in south-east Asia, but originated in central Africa; F has been found in central Africa, south America and eastern Europe; G and A/G have been observed in western and eastern Africa and central Europe. Subtype H has only been found in cen
