HIV Type 1 Subtype C and CB Pol Recombinants Prevail at the Cities with the Highest AIDS Prevalence Rate in Brazil

Abstract

HIV-1 B is predominant in Brazil, but HIV-1 C has increasingly been reported in the south of the country. However, many samples clustering with clade C are actually a recombinant, with a small B segment at RT (CRF31). Samples (209) from the three cities with the highest aids prevalence rate are analyzed. Partial polymerase sequences from HIV RNA made it possible to determine HIV clades and recombination patterns and to identify primary drug resistance mutations (DRMs). The incidence was estimated with a BED assay. HIV-1 C and CRF31 patterns were twice as frequent as clade B at all sites, but the proportion of C and CRF31 patterns was significantly different among sites. The incidence estimate for SC was 2.6 persons-years. Infection in recent or younger cases showed no association with clade C. Surveillance DRM was observed in 8.3% (95% CI 5-13), mostly to NNRTIs. Clade F pol genomes had significantly more primary DRM.

Comprehensive Characterization of HIV-1 Molecular Epidemiology and Demographic History in the Brazilian Region Most Heavily Affected by AIDS

“…In terms of molecular diversity, our results corroborate previous studies that also reported a large dominance of subtype C (ϳ65%) in SC state (30)(31)(32)(33) and a more diverse epidemic in RS state, mainly because of the high prevalence of BC mosaic forms in the latter (ϳ25%) (34)(35)(36). In both states, a low prevalence of subtype F1 and BF1 recombinants (ϳ3%) was observed, while this frequency can reach up to 20% in northern regions of Brazil (37,38) and 40% in Argentina (39).…”

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.…”

Estimates of HIV-1 incidence based on serological methods: a brief methodological review

“…Indeed, a preponderance of subtype C was detected among males with recent infection in Curitiba, and the overall incidence in this study was of 2.86 persons/years (95%CI: 1.04-4.68). Similar results were obtained for the two Santa Catarina cities, that presented an overall incidence estimate of 2.6 persons/year (95%CI: ±0.8) 56 , in a virological scenario where subtype C predominates. Considering the WHO criticisms 30 about the sensitivity and specificity of the BED-CEIA to estimate HIV incidence in epidemiological scenarios including non-B HIV-1 subtypes, in a preliminary study we proposed a criterion based on the matching results of two assays (BED-CEIA and Avidity index) aiming to improve the accuracy of these serological approaches to estimate HIV incidence rates 57 .…”

“…More recently, BED-CEIA has been employed in Brazil for estimating HIV incidence and to assess the molecular characterization of newly identified HIV-1 infections in people seeking HIV diagnosis in voluntary centers for counseling and testing in Rio de Janeiro 54 , and Curitiba (Paraná State) 55 , and in a Public Health Laboratory serving communities with high prevalence of HIV infection in Santa Catarina State (Camboriú and Itajaí) 56 . Indeed, a preponderance of subtype C was detected among males with recent infection in Curitiba, and the overall incidence in this study was of 2.86 persons/years (95%CI: 1.04-4.68).…”