High Levels of Primary Antiretroviral Resistance Genotypic Mutations And B/F Recombinants in Santos, Brazil

Abstract

This study characterized HIV-1 among antiretroviral-naïve populations presenting recent infection (RI) or long-standing infection (LSI). Sera collected from January 1999 to December 2001 at an anonymous HIV testing site in Santos, Brazil, were submitted to serologic testing algorithm for recent HIV seroconversion (STARHS). The STARHS methodology uses a combination of a sensitive and a less sensitive version of an anti-HIV enzyme immunoassay (EIA), and specimens found to be positive on the sensitive EIA and negative on the less sensitive EIA are considered to represent RI. HIV-1 V3 and pol regions of those with RI and LSI were compared. Antiretroviral resistance was defined solely by genotypic analysis. Ninety samples were evaluated representing those taken from an original cohort of 345 individuals, for whom adequate samples were available. Of 90 HIV-positive individuals, 25 presented RI. Cumulatively, 36.8% of those with RI and 25% of those with LSI presented resistance to at least one antiretroviral class. In the pol and V3 regions, 47% and 53% of those with RI presented clade B viruses and B/F recombinant viruses, respectively, whereas 56.2%, 41.7%, and 2.1% of those with LSI harbored clades B, B/F, and clade C viruses, respectively. Primary resistance and the prevalence of B/F recombinants was high in this population. Monitoring HIV-1 genetic diversity is important for developing vaccines and treatment strategies.

Molecular characterisation of newly identified HIV-1 infections in Curitiba, Brazil: preponderance of clade C among males with recent infections

“…The prevalence of pDRM was similar to most of the studies in the country (Brindeiro et al 2003, Barreto et al 2006, Rodrigues et al 2006, Brigido et al 2007, EyerSilva et al 2008), but some studies showed higher rates (Pedroso et al 2007, Sucupira et al 2007). These studies varied in patient population selection, type of genetic material analysed and the list of mutations considered for surveillance purposes.…”

“…These studies varied in patient population selection, type of genetic material analysed and the list of mutations considered for surveillance purposes. The study with higher levels of resistance was based on proviral DNA (Sucupira et al 2007), whereas most of the other studies were based on HIV-1 virion RNA. Few studies have compared plasma and cell mutation profiles, but cell/plasma discordance is not uncommon (Bon et al 2007) and one recent study suggested an astonishingly high degree of heterogeneity among peripheral blood mononuclear cells (PBMCs) in regards to resistance (Quan et al 2008).…”

“…Brazil has many studies on HIV-1 subtypes and primary drug resistance from different areas in the country, and most of the recent ones suggest low rates of primary drug resistance, varying from 1.4-8.3% (Brindeiro et al 2003, Barreto et al 2006, De Medeiros et al 2006, Rodrigues et al 2006, Brigido et al 2007, Sá-Ferreira et al 2007, Eyer-Silva et al 2008. A study performed in Santos has reported the highest drug resistance rates in the country, with 37% among recent infections and 25% among chronic cases (Sucupira et al 2007). The predominant clade in Brazil is HIV-1 B, except in some areas in the south of the country, where clade C predominates (Bongertz et al 2000, Brindeiro et al 2003, Gadelha et al 2003, Cerqueira et al 2004, Barreto et al 2006, Rodrigues et al 2006, Stefani et al 2007).…”

Genetic diversity and primary resistance among HIV-1-positive patients from Maringá, Paraná, Brazil

“…The L10I/V polymorphism is a mutation that is weakly associated with a reduced response of the virus to some PIs 26 . The combination of minor mutations M36I and L10I/V has been suggested to result in the subsequent development of mutation L90M, causing virological failure and some level of resistance to all PIs 29,36 .…”

Prevalence of HIV type 1 drug resistance mutations in treatment-naïve and experienced patients from resource-limited settings with universal access to antiretroviral therapy: a survey in two small Brazilian cities

“…Up to the present time, this seems not to be the case in Brazil . When compared to figures reported from developed nations, most studies from Brazil have found relatively low rates of primary HIV-1 drug resistance (Brindeiro et al 1999, Dumans et al 2002, Brindeiro et al 2003, Pires et al 2004, Brigido et al 2005, Barreto et al 2006, Medeiros et al 2006, Rodrigues et al 2006, SaFerreira et al 2007, even though isolated surveys recently reported worrisome rates in the port cities of Santos (Sucupira et al 2007) and Salvador (Pedroso et al 2007). Also, resistance rates in Brazil are being reported from studies primarily based in large urban centers and little is known about the prevalence of resistant strains in innermost parts of the country.…”