Molecular Epidemiological Analysis of Paired pol/env Sequences from Portuguese HIV Type 1 Patients

Abstract

The advent of new therapeutic approaches targeting env and the search for efficient anti-HIV-1 vaccines make it necessary to identify the number of recombinant forms using genomic regions that were previously not frequently sequenced. In this study, we have subtyped paired pol and env sequences from HIV-1 strains infecting 152 patients being clinically followed in Portugal. The percentage of strains in which we found discordant subtypes in pol and env was 25.7%. When the subtype in pol and env was concordant (65.1%), the most prevalent subtypes were subtype B (40.8%), followed by subtype C (17.8%) and subtype G (5.3%). The most prevalent recombinant form was CRF14_BGpol/Genv (7.2%).

Novel Multiregion Hybridization Assay for the Identification of the Most Prevalent Genetic Forms of the Human Immunodeficiency Virus Type 1 Circulating in Portugal

“…15,17 Accordingly, the MHA described in this work (vMHA B/G/02 ) was planned to allow a rapid and unambiguous discrimination of the most prevalent HIV-1 subtypes (subtype B and G) and circulating recombinant forms (CRF02_AG and CRF14_BG) that comprise the majority of the HIV-1 strains circulating in Portugal. [18][19][20][21] In a recent study 28 the same predominant subtypes were found, although an unusually high (and possibly nonrepresentative) prevalence of subtype C was reported. However, the basic features of your method allows for quick updating in the face of a change in distribution of subtypes in Portuguese epidemiology, such as an increased prevalence of a nondominant subtype.…”

Analysis of a Local HIV-1 Epidemic in Portugal Highlights Established Transmission of Non-B and Non-G Subtypes

“…Since its origin in Africa approximately 100 years ago, HIV-1 has continuously been undergoing genetic diversification that is enhanced by the massive globalization of the human population (21). Despite the perception that current antiretroviral regimens have comparable efficacies across existing diverse HIV-1 subtypes, there is evidence showing that some HIV-1 subtypes may have a transmission advantage, higher replicative efficiency, or even altered drug susceptibility (7)(8)(9)(10)(11), raising awareness on the relevance of investigating HIV-1 diversity.…”

“…Existing data show that Portugal contrasts with the rest of western Europe in its distribution of HIV-1 subtypes (18,21). It is important to gain a further understanding on the causes underlying this difference, also in light of the evidence supporting a recent increase in infections with non-B HIV-1 subtypes in several western European countries (15)(16)(17)44).…”

“…Portugal contrasts with the rest of western Europe in its distribution of HIV-1 subtypes. In addition to the B subtype, Portugal also has a high prevalence of the G subtype (18)(19)(20)(21)(22)(23). The high prevalences of the B and G subtypes are thought to have promoted the appearance among intravenous drug users (IDU) of different types of B/G recombinant strains, namely, CRF14_BG, which is considered to have emerged in Portugal in the early 1990s and then spread to Spain and other European countries (24)(25)(26).…”

HIV-1 Diversity and Its Implications in Diagnosis, Transmission, Disease Progression, and Antiretroviral Therapy

“…Subtype F predominates in Central Africa (Carr et al, 2010b;Soares et al, 2010), South America (Avila et al, 2002;Munerato et al, 2010) and Eastern Europe (Fernandez-Garcia et al, 2009;Paraschiv, Foley, and Otelea, 2011). Subtype G viruses are prevalent in Central and Western Africa (Hawkins et al, 2009;Kalish et al, 2004), as well as in Portugal (Abecasis et al, 2011;Esteves et al, 2003;Esteves et al, 2002;Palma et al, 2007) and Spain Trevino et al, 2011). Subtypes H and J were described in Central Africa Mokili et al, 1999;Yamaguchi et al, 2010) and in Angola (Bartolo et al, 2005;Bartolo et al, 2009d).…”