There are two types of HIV: HIV-1 and HIV-2
The strains of HIV-1 can be classified into three groups :
the "major" group M, the "outlier" group O and the "new" group N. 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 central Africa; J only in central America; and K only in the Democratic Republic of Congo and Cameroon. Does subtype affect disease progression?
A study presented in 2006 found that Ugandans infected with subtype D or recombinant strains incorporating subtype D developed AIDS sooner than those infected with subtype A, and also died sooner. The study's authors suggested that subtype D is more virulent because it is more effective at binding to immune cells.5
An earlier study of sex workers in Senegal, published in 1999, found that women infected with subtype C, D or G were more likely to develop AIDS within five years of infection than those infected with subtype A.6 What are the treatment implications?
Most current HIV-1 antiretroviral drug regimens were designed for use against subtype B, and so hypothetically might not be equally effective in Africa or Asia where other strains are more common. At present, there is no compelling evidence that subtypes differ in their sensitivity to antiretroviral drugs. However, some subtypes may occasionally be more likely to develop resistance to certain drugs. In some situations, the types of mutations associated with resistance may vary. This is an important subject for future research.
Maybe there is some truth in what Mabila is saying about HIV/AIDS & race