Frequency of subtype B and F1 dual infection in HIV-1 positive, Brazilian men who have sex with men

Abstract

BackgroundBecause various HIV vaccination studies are in progress, it is important to understand how often inter- and intra-subtype co/superinfection occurs in different HIV-infected high-risk groups. This knowledge would aid in the development of future prevention programs. In this cross-sectional study, we report the frequency of subtype B and F1 co-infection in a clinical group of 41 recently HIV-1 infected men who have sex with men (MSM) in São Paulo, Brazil.MethodologyProviral HIV-1 DNA was isolated from subject's peripheral blood polymorphonuclear leukocytes that were obtained at the time of enrollment. Each subject was known to be infected with a subtype B virus as determined in a previous study. A small fragment of the integrase gene (nucleotide 4255–4478 of HXB2) was amplified by nested polymerase chain reaction (PCR) using subclade F1 specific primers. The PCR results were further confirmed by phylogenetic analysis. Viral load (VL) data were extrapolated from the medical records of each patient.ResultsFor the 41 samples from MSM who were recently infected with subtype B virus, it was possible to detect subclade F1 proviral DNA in five patients, which represents a co-infection rate of 12.2%. In subjects with dual infection, the median VL was 5.3 × 104 copies/ML, whereas in MSM that were infected with only subtype B virus the median VL was 3.8 × 104 copies/ML (p > 0.8).ConclusionsThis study indicated that subtype B and F1 co-infection occurs frequently within the HIV-positive MSM population as suggested by large number of BF1 recombinant viruses reported in Brazil. This finding will help us track the epidemic and provide support for the development of immunization strategies against the HIV.

Variability of HIV-1 Genomes among Children and Adolescents from São Paulo, Brazil

“…Janini et al [40] reported the first case of both horizontal and subsequent vertical transmission of 2 distinct HIV-1 subtypes from 1 dually infected person to another. In the present study, dual infections were evident in three patients, lending further support to previous studies [41], [42], [43], as this event is far more common in Brazil where both subtypes co-circulate. The fact that existence of dual infection in some patients contrasts with the hypothesis that an initial viral infection produces some degree of protection against a second infecting HIV subtype.…”

Deep Sequencing of HIV-1 near Full-Length Proviral Genomes Identifies High Rates of BF1 Recombinants Including Two Novel Circulating Recombinant Forms (CRF) 70_BF1 and a Disseminating 71_BF1 among Blood Donors in Pernambuco, Brazil

“…It is also conceivable that the discordances in the HIV subtypes in PBMCs and plasma are likely due to low-level minority strains present as B/BF1 variants that are not detected with bulk plasma sequencing or that the F1 viruses shed in the plasma were more fit. The evidence of dual infections in this study adds support to previous studies [35] , [36] , [37] , [38] , [39] , as this event is far more common in Brazil where these subtypes co-circulate. Furthermore, these data agree with the consensus that the presence of two or more HIV-1 subtypes within an infected individual is relatively frequent [40] , [41] .…”

Enhanced detection of viral diversity using partial and near full‐length genomes of human immunodeficiency virus Type 1 provirus deep sequencing data from recently infected donors at four blood centers in Brazil

“…It is also conceivable that the discordances in the HIV subtypes in PBMNCs and plasma are due to low‐level minority strains present that are not detected with bulk plasma sequencing or that the replicating viruses shed in the plasma were more fit. The evidence of dual infections in this study adds support to previous studies, demonstrating that this event is far more common where multiple subtypes cocirculate, which is now the case in Brazil. It is unclear from this study whether the occurrence of multiple distinct HIV strains was the result of superinfection with a second variant at a later time or whether simultaneous infection with multiple viral strains occurred during a single transmission event.…”