Frontiers in HIV Research

Volume: 2

Current Studies in HIV Research

Indexed in: EBSCO.

Current Studies in HIV Research brings key topics in HIV/AIDS research to the fore by compiling reviews prepared by HIV/AIDS experts. Readers will benefit from the extensive range of topics covered ...
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Diversity and Global Epidemiology of HIV

Pp. 3-10 (8)

Kazem Baesi, Seyed Younes Hosseini, Ali Teimoori and Mohammad Gholami


HIV has probably originated from multiple zoonotic transmissions of Simian Immunodeficiency Virus (SIV) from non-human primates to humans in West and Central Africa. There are two HIV types: HIV type 1 (HIV-1) groups M, N, O and P and HIV type 2 (HIV-2) groups A–H. Within the HIV-1 group M, nine subtypes are found, designated by the letters A–D, F–H, J, and K. Within a subtype, changes in the amino acid sequence is observed in the range of 8-17%, but it can be as high as 30%, while differences between subtypes are generally found in the range of 17-35%.

In fact, when new combinations between different HIV-1 subtypes occurs, it results in different Unique Recombinant Forms (URFs), some developed into Circulating Recombinant Forms (CRFs) as propagated in three or more epidemiologically unlinked individuals. The viruses fueling these epidemics vary according to geographical regions, with clade C virus being the most prevalent worldwide, and clade B being currently the most prevalent in the United States and Europe.

Thirty years after the first description of AIDS, an estimated 35.0 million [33.2 million–37.2 million] people were living with HIV at the end of 2013. 2.1 million [1.9–2.4 million] had become newly contaminated with HIV in 2013, including 240000 children, and 1.5 million [1.4–1.7 million] HIV-infected persons died.


AIDS, CRF, Diversity, Epidemiology, HIV, Mutation, Recombination, Sequence, Subtype, URF.


Hepatitis and AIDS Department, Pasteur Institute of Iran, Pasteur Ave., Tehran 1316943551, Tehran, Iran; Shiraz HIV/AIDS Research Center, Shiraz University of Medical Sciences, Zand, Iran.