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Transmission of resistant HIV-strains in patients with documented date of HIV-infection in the German HIV-seroconverter cohort (1997-2007). A decade of observation
Presented by Osamah Hamouda, Germany.
B. Bartmeyer1, C. Kuecherer2, J. Werning1, C. Kollan1, O. Hamouda1
1Robert Koch-Institute, HIV/AIDS, STD Unit, Dept. Infectious Disease Epidemiology, Berlin, Germany, 2Robert Koch-Institute, HIV Variability and Molecular Epidemiology, Berlin, Germany
Background: Transmission of primary drug resistance cannot be precisely observed in HIV-patients with unknown duration of infection. Epidemiological analysis focused on trends of transmission of resistant HIV in patients with known date of infection in the German HIV-Seroconverter Cohort.
Methods: As of 31.12.2007 1563 individuals with a last negative and a first positive HIV antibody test within a maximum three year interval as well as individuals with an acute seroconversion confirmed by laboratory criteria were defined as HIV-seroconverters. Genotypic resistance testing was performed in treatment naïve patients of the HIV-Seroconverter Cohort (Stanford algorithm, version 4.3.1, 2007). Statistical analysis was performed by Chi squared test for trend.
Results: The majority of patients were male (92%, 1447/1563) belonging to the risk group of men having sex with men, MSM (82%), followed by heterosexuals, IDU and patients of countries with high prevalence (7.8%, 3.8% and 2.5%, respectively). One third of patients were acute (29.1%), two thirds were documented seroconverters (1108/1563). 1043 (67%) samples were analysed by genotypic resistance testing. Resistant strains were identified in 143 individuals (13.7%, CI 11.7-15.9). Primary NRTI-resistant strains were predominant (6.6%, 69/1043), followed by NNRTI- and PI-related resistance (3.0% and 2.4%, respectively). Dual- and multi-resistance appeared in 1.6% and 0.4% of genotyped samples, respectively. Transmission of resistant HIV strains tended to decrease over time (p= 0.05). A significant decline in NRTI- as well as PI-associated resistance was observed over time (NRTI p=0.02; PI p=0.007, respectively). Whereas NNRTI-related resistance seemed to increase but did not reach significance (p= 0.18).
Conclusions: In contrast to many studies of prevalent HIV-infections, the German HIV-Seroconverter Cohort provides the opportunity to examine trends in transmission of resistant HIV among newly infected patients. The significant decrease of NRTI- and PI- resistance might be associated with changing prescription practice, new generation PIs and broader application of genotypic resistance analysis during therapy.
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