Autochthonous horizontal transmission of a CRF02_AG strain revealed by a human immunodeficiency virus type 1 diversity survey in a small city in inner state of Rio de Janeiro, Southeast Brazil

Abstract

Key words: Brazil -CRF02_AG -human immunodeficiency virus type 1 -molecular epidemiology -transmission clustersThe extremely high genetic diversity of human immunodeficiency virus type 1 (HIV-1) has been successfully used to study the regional and global distribution of different viral groups and subtypes (Hu et al. 1996) and makes it possible to trace patterns of viral spread between populations, groups and people (Kuiken et al. 2000). Phylogenetic analysis allows classification of HIV-1 strains into three groups: M, N and O. The M (main) group, the widest spread, has been further subdivided into at least nine subtypes (A-D, F-H, J, and K) and 32 circulating recombinant forms (CRF), whereas a high diversity of unique intersubtype recombinant forms has also been demonstrated (Leitner et al. 2005). In Brazil, molecular analyses of HIV-1 nucleotide sequences have shown an epidemic driven mainly by three group M subtypes: B, C, and subsubtype F1 (heretofore designated subtype F1), as well as a myriad of unique BF1 intersubtype recombinants (Morgado et al. 1998, Tanuri et al. 1999, Vicente et al. 2000, Soares et al. 2003. Isolated cases of other subtypes, such as subtype D (Morgado et al. 1998, CoutoFernandez et al. 2006), subtype A (Caride et al. 2000, CRF02_AG (Pires et al. 2004, Couto-Fernandez et al. 2005), CRF28_BF and CRF29_BF (De Sa Filho et al. 2006 have also been reported.Phylogenetic analyses of HIV-1 nucleotide sequences are being increasingly used to better understand epidemiological patterns of viral spread. Such studies have proven to be invaluable to clarify the routes of viral transmission in community settings (Holmes et al. 1995, Brown et al. 1997, to establish (Ou et al. 1992, Blanchard et al. 1998 or rule out (Holmes et al. 1993, Jaffe et al. 1994) iatrogenic viral transmission, to study the pathways of viral spread among clusters of patients (Leitner et al. 1996, Robbins et al. 2002, to trace the geographic origin of recently introduced subtypes (Gao et al. 1996, Kato et al. 1999, Yu et al. 2001, CoutoFernandez et al. 2006, to infer the demographic history and date of origin of epidemic spread (Robbins et al. 2003, Bello et al. 2006, to investigate unusual forms of viral transmission (Goujon et al. 2000, Andreo et al. 2004, and has also found forensic applications (Albert et al. 1994, Banaschak et al. 2000, Metzker et al. 2002, Lemey et al. 2005. Phylogenetic analyses of HIV-1 sequences have also been used to provide evidence of a high incidence molecular profile, as evidenced by multiple transmission clusters, low level of sequence diversity and signature amino acid substitutions (Liitsola et al. 1998, Oelrichs et al. 2000, Shankarappa et al. 2001, Nguyen et al. 2002, and of an old and mature epidemic pattern, given the high sequence diversity and the absence of transmission clusters (Vidal et al. 2000, Trask et al. 2002.It is known that the AIDS epidemic in Brazil is spreading from the large urban centers towards small cities and the innermost parts of the country (Szwarcwald et al. 20...

Brazilian Network for HIV Drug Resistance Surveillance: a survey of individuals recently diagnosed with HIV

“…Subtype F and several BF mosaics as well Unique Recombinant Forms (URFs) are the other major non-B strain spread throughout the country and corresponds to approximately 13% of the samples analyzed in our study. Interestingly, a CRF2 (A/G) isolate was found in Salvador Bahia, corroborating previous reports regarding the introduction of this west African strain in Brazil [29].…”

“…Interestingly, a CRF2 (A/G) isolate was found in Salvador Bahia, corroborating previous reports regarding the introduction of this west African strain in Brazil [29]. …”

Transmitted Drug Resistance among People Living with HIV/Aids at Major Cities of Sao Paulo State, Brazil

“…This is further detailed elsewhere [16]. Also, a single CRF02_AG was identified, and although it is the most disseminated HIV recombinant form worldwide, it is rather uncommon at South America, with a report of its presence in Brazil [17]. In this study, we found an association within Campinas sequences of transmitted resistance to subtype B ( P = 0.05) using either CPR or IAS criteria, in agreement with Sprinz et al [4], where TDR was predominantly found among subtype B infected individuals.…”

The Use of Bioinformatics for Studying HIV Evolutionary and Epidemiological History in South America

“…All these CRF are thought to have been generated locally by recombination of the prevailing HIV-1 subtypes. Other HIV-1 clades have also been sporadically detected in South America, such as the subtype D and the CRF02_AG in Brazil [25–27] and the CFR16_AD and CRF06_cpx in Argentina [14, 28]. These forms were likely introduced by African immigrants, and have not achieved epidemic relevance to date.…”