Different Epidemic Potentials of the HIV-1B and C Subtypes

Abstract

Abstract. HIV, the cause of AIDS in humans, is characterized by great genetic heterogeneity. In particular, HIV-1 group M subtypes are responsible for most of the infections worldwide. We investigate the demographic history of HIV-1B and HIV-1C subtypes in South Africa and Brazil using both a parametric and a nonparametric approach based on coalescent theory. Our results show that although both subtypes are spreading exponentially in Brazil, the HIV-1C growth rate is about twice that of Brazilian HIV-1B or South African HIV-1C, providing evidence, for the first time, of a different epidemic potential between two HIV-1 subtypes. The present study not only may have important consequences for devising future vaccination and therapeutic strategies, but also offers additional evidence that skyline plots are indeed a simple and powerful tool for monitoring and predicting the behavior of viral epidemics.

Evolution of HIV-1 in India

“…Factors related to C viral entry and pathogenesis such as CCR5 and nonsyncytium-inducing properties of C isolates, may also contribute to the increased spread of C viruses. Interestingly, though both subtype B and C are spreading exponentially in Brazil, the subtype C growth rate is about twice that of subtype B there; thus providing evidence of a different epidemic potential between two HIV-1 subtypes [19].…”

Extremely Rapid Spread of Human Immunodeficiency Virus Type 1 BF Recombinants in Argentina

“…More specifically, previous coalescent analyses of env, gag and reverse transcriptase genes revealed growth rates of 0.386 to 0.609 year Ϫ1 for the parenterally transmitted subtype B population of Western Europe and North America during the 1980s (16), roughly one-fifth of the rate observed here. However, despite this initially high rate of exponential population growth, BF recombinants seem to have reached the population carrying capacity in relation to MTCT, as opposed to subtypes B and C in adults from Brazil, which may still be spreading at exponential rates (12).…”

Heterosexual transmission of human immunodeficiency virus type 1 subtype C in southern Brazil

“…Currently, depending on the state, 27-79% of HIV infections are caused by HIV-1C, 23-45% by HIV-1B, 3-29% by CRF31 BC and other BC recombinants, and HIV-1F and its recombinants account for up to 10% of infections. [6][7][8][9][10][11][12][13][14][15][16] Recent studies suggest that the HIV-1 epidemics in Brazil has initiated with multiple introductions of HIV-1B during the 60s or 70s 17,18 in the largest cities of Southeast, and then disseminated throughout the country. HIV-1F and C had a monophyletic entry in the country, the former in the Southeast and the latter in the South, approximately 10-15 years after HIV-1B.…”