Update on Primary HIV-1 Resistance in Argentina

Abstract

Here we present a survey including 52 drug-naive recently HIV-1-infected subjects from Buenos Aires City and province (79%) and 3 other regions in Argentina (21%). Recent infections were established from previous negative serology (32/52), indeterminate Western blot (12/52), or acute retroviral syndrome after high-risk HIV exposure (8/52) within 9 months before genotyping (median time, 4.2 months). Genotyping was performed from plasma by sequencing both protease and reverse transcriptase. Phylogenetic analysis combined with bootscanning resulted in 21 subtype B sequences and 31 B/F recombinants (RecBF). On protease, minor resistance-related mutations were found in both subtype B and RecBF with low frequencies. The substitution L89M, recently suggested as a resistance-related mutation in some subtype F viruses, was observed in 1 RecBF. On reverse transcriptase, major resistance-related mutations were found in 4 of 52 (7.7%) patients from different health centers: M41L (subtype B) and K103N+/-P225H (1 RecBF and 2 subtype B). The greater than 5% resistance threshold found indicates a need for sentinel resistance surveillances calling for an update in the current resistance testing guidelines in Argentina.

Surveillance of HIV Transmitted Drug Resistance in Latin America and the Caribbean: A Systematic Review and Meta-Analysis

“…In Argentina, surveys performed in Buenos Aires before 2005 generally reported low TDR prevalence in chronically infected individuals: 2.3% (n = 86, 1997–2000) [ 116 ]; 2.8% (n = 250, 2003–2005)[ 117 ]; 3.2% (n = 284, 2003–2005) [ 118 ]; while some of these older studies also reported moderate or borderline high TDR in recently infected individuals: 15.4% (n = 13, 1997–2000) [ 116 ]; 7.7% (n = 52, 2004–2005) [ 119 ]; 7.1% (n = 28, 2003–2005) [ 117 ], suggesting increasing TDR trends in time in Buenos Aires. Interestingly, a study including 16 female sex workers in 6 Argentinean cities, performed between 2000–2002, showed a high overall TDR level of 12.5% associated to NRTI and NNRTI [ 120 ].…”

Acute retroviral syndrome and high baseline viral load are predictors of rapid HIV progression among untreated Argentinean seroconverters

“…It is possible that HIV subtype could influence viral load set point and subsequent course of HIV infection [36-38]. We are currently studying the potential influence of the two most prevalent subtypes of HIV-1, B and BF [52-56], on disease progression in our country.…”

Detection of HIV-1 dual infections in highly exposed treated patients

“…It has been observed that several drug resistance-associated mutations in the pol region of BF recombinant variants include mutations which are in fact natural polymorphisms of the BF strains [10,11]. Therefore, we only considered major PI-resistance associated mutations to categorize viral variants as resistant.…”