The increasing prevalence of HIV-1 subtype C in Southern Brazil and its dispersion through the continent

Abstract

The HIV-1 has evolved swiftly and the scenario of HIV-1 genetic diversity is constantly changing. In South America, recombinant forms of subtypes B, F1, and BF1 have historically driven the HIV-1 epidemic. In recent years, however, infection with subtype C has gained prominence as its prevalence increased in Southern Brazil as well as neighboring countries. Current studies point to a single introduction of closely related strains as the beginning of the Brazilian subtype C epidemic. However, the place of origin of these strains, date, and route of introduction are under continuous debate as well as the clinical outcomes of the emergence of subtype C. Therefore, this paper reviews the history of the HIV-1 subtype C in Brazil, particularly in the Southern region, covering its demographic and evolutionary history and the possible implications to the Brazilian AIDS epidemic as well as to neighboring countries.

Dynamics and molecular evolution of HIV-1 strains in Sicily among antiretroviral naïve patients

“…Intriguingly, a single C-related sequence with unresolved classification and belonging to a native Italian homosexual man, strongly correlated to a group of sequences described in Apulia (Monno et al, 2012) and in France , and closely related to those described by other authors in Brazil (Brígido et al, 2007;Gräf and Pinto, 2012;Passaes et al, 2009a,b;Santos et al, 2006). Furthermore, the detection of such URFs-BC in three different geographic areas with no evidence of epidemiological link together with a local divergent evolutionary pathway, could represent a potential candidate for a novel CRF_BC profile, although a whole genome sequencing is mandatory to definitely confirm this evidence.…”

Sensitive, Subtype Independent HIV-1 PCR Assays for Assessment of Residual Viremia and Total HIV-1 DNA

“…The methods need to be sensitive but also subtype-independent since many research and clinical environments are dealing with a diversity of HIV-1 subtypes. Several recent studies have reported increasing HIV-1 subtype diversity in different parts of the world, including Sweden and USA [15][16][17][18]. Previous reports have described in-house assays or modified commercial assays that in-has been proposed as surrogate measures of the viral reservoir [31][32][33].…”

Contribution of Epidemiological Predictors in Unraveling the Phylogeographic History of HIV-1 Subtype C in Brazil

“…Although HIV-1 subtype B (HIV-1B) dominates in many countries in Europe and the Americas (2), more than 50% of the infections worldwide are caused by HIV-1 subtype C (HIV-1C), which is the most prevalent subtype in southern African countries and India and is increasing in prevalence in China and South America (2,4).…”

“…In the southern regions of Brazil, however, the spread of HIV-1B is matched by that of HIV-1C, which cocirculates in similar proportions and can even be responsible for up to 80% of infections (4). In addition, the two southernmost Brazilian states, Rio Grande do Sul (RS) and Santa Catarina (SC), have the highest AIDS incidence in the country (6).…”

“…These patterns have motivated several investigations into the history and dynamics of the Brazilian HIV-1C epidemic (HIV-1C_BR), which is estimated to have originated in the 1960s and 1970s in the state of Paraná (PR) (7,8,9). The fact that HIV-1C incidence in more northern states has only recently begun to increase (4,(10)(11)(12)(13)(14) suggests viral diffusion is driven by unknown factors that promote fast dissemination to the south while constraining spread to the north.…”