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Characterization of the patterns of drug-resistance mutations in newly diagnosed HIV-1 infected patients naïve to the antiretroviral drugs

Claudia Alteri1, Valentina Svicher1, Caterina Gori2, Roberta D'Arrigo2, Massimo Ciccozzi3, Francesca Ceccherini-Silberstein12, Marina Selleri2, Stefano Aviani Bardacci4, Massimo Giuliani5, Paola Elia2, Paola Scognamiglio2, Roberta Balzano2, Nicoletta Orchi2, Enrico Girardi2, Carlo Federico Perno12* and SENDIH Study Group

Author Affiliations

1 Department of Experimental Medicine and Biochemical Sciences, University of "Tor Vergata" Rome, Italy

2 National Institute for Infectious Diseases "L. Spallanzani", Rome, Italy

3 Department of Infectious Parasite and Immuno-Mediate Diseases, Istituto Superiore di Sanità, Rome, Italy

4 AIDS Center, Belcolle Hospital, Viterbo, Italy

5 Division of Dermatological Infectious Diseases, STI/HIV Unit, San Gallicano Institute, Rome, Italy

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BMC Infectious Diseases 2009, 9:111  doi:10.1186/1471-2334-9-111

Published: 16 July 2009



The transmission of HIV-1 drug-resistant strains in drug naive patients may seriously compromise the efficacy of a first-line antiretroviral treatment. To better define this problem, a study in a cohort of newly diagnosed HIV-1 infected individuals has been conducted. This study is aimed to assess the prevalence and the patterns of the mutations recently associated with transmitted drug resistance in the reverse transcriptase (RT) and in protease (PR) of HIV-1.


Prevalence of transmitted drug resistant strains is determined in 255 newly diagnosed HIV-1 infected patients enrolled in different counselling and testing (CT) centres in Central Italy; the Avidity Index (AI) on the first available serum sample is also used to estimate time since infection. Logistic regression models are used to determine factors associated with infection by drug resistant HIV-1 strains.


The prevalence of HIV-1 strains with at least one major drug resistance mutation is 5.9% (15/255); moreover, 3.9% (10/255) of patients is infected with HIV nucleoside reverse transcriptase inhibitor (NRTI)-resistant viruses, 3.5% (9/255) with HIV non-NRTI-resistant viruses and 0.4% (1/255) with HIV protease inhibitor (PI)-resistant viruses. Most importantly, almost half (60.0%) of patients carries HIV-1 resistant strains with more than one major drug resistance mutation. In addition, patients who had acquired HIV through homosexual intercourses are more likely to harbour a virus with at least one primary resistance mutation (OR 7.7; 95% CI: 1.7–35.0, P = 0.008).


The prevalence of drug resistant HIV-1 strains among newly diagnosed individuals in Central Italy is consistent with the data from other European countries. Nevertheless, the presence of drug-resistance HIV-1 mutations in complex patterns highlights an additional potential risk for public health and strongly supports the extension of wide genotyping to newly diagnosed HIV-1 infected patients.