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Session 116 Poster Abstracts
Transmission of HIV Drug Resistance
Wednesday, 1:30 - 3:30 pm
Hall A


672    
Transmission of Drug-resistant Viruses in Recent HIV Seroconverters in Spain
Carmen de Mendoza*1, C Rodriguez2, J Colomina3, C Tuset4, F Garcia5, J Eiros6, A Corral1, J del Romero2, J Aguero7, P Leiva8, J Torre-Cisneros9, I Viciana10, J Pedreira11, R Ortiz12, V Soriano1, and on behalf of the Spanish Seroconverter Study Group.
1Hosp Carlos III, Madrid, Spain; 2Ctr Sanitario Sandoval, Madrid, Spain; 3Hosp de la Ribera, Valencia, Spain; 4Hosp Clin, Valencia, Spain; 5Hosp San Cecilio, Granada, Spain; 6Hosp Univ, Valladolid, Spain; 7Hosp Marques de Valdecilla, Santander, Spain; 8Hospital Central de Asturias, Oviedo, Spain; 9Hosp Reina Sofia, Cordoba, Spain; 10Hosp Virgen de la Victoria, Malaga, Spain; 11Hosp Juan Canalejo, A Coruņa, Spain; and 12Hosp Clin, Valladolid, Spain

Background:  The rate of transmission of drug resistance has fluctuated over time in Spain with average rates of 15%. 

Methods:  Genotypic drug resistance was examined in consecutive, recent HIV seroconverters (< 12 months from first HIV exposure) from January 1997 to September 2004 in 11 different hospitals across Spain. Only major drug-resistance mutations at the RT and protease were considered for this analysis. Phylogentic analyses were done for HIV subtyping and clustering between individuals.

Results:  A total of 172 recent HIV-seroconverters were identified. Mean time of infection was 7 months and 68.5% were infected through homosexual contact. Overall, the rate of primary drug-resistance mutations was 13.7% and by year as follows:  33.3% (1997), 29.4% (1998), 20% (1999), 14.3% (2000), 3.3% (2001), 14.8% (2002), 10.4% (2003), and 12% (2004). There was a significant increase of K103N in 2004 with respect to previous years (p = 0.025). A total of 14 individuals carried non-B subtypes (7 CRF14_BG, 2 F, 2 BF, 2 C, and 1 CRF02_AG) and was restricted to the last 3 years. A significant association between non-B subtypes and acquisition of HIV infection through intravenous drug use (58.3%, p < 0.001) and heterosexual contact (15.4%, p < 0.05) was observed with respect to homosexual contact (2%). Moreover, the CRF14_BG was specifically associated with injecting drug users (5 subjects) or their heterosexual contact (2 subjects). Phylogenetic analyses confirmed transmission of HIV infection during HIV seroconversion in 6 couples and a cluster of 3 injecting drug users infected with CRF14_BG.

Conclusions:  The overall rate of primary drug resistance in recent HIV seroconverters seems to be stable in 2004, although 3 new aspects have been observed. First, resistance to non-nucleoside reverse transcriptase inhibitors (NNRTI) is transmitted more frequently with respect to others. Second, transmission of non-B subtypes has increased, and the new CRF14_BG is spreading mainly among injecting drug users and their heterosexual partners. Third, the evidence for transmission during seroconversion suggests that prevention strategies should be reinforced in risky populations.

Keywords: recent HIV seroconverters; drug resistance; non-B subtypes