French national sentinel survey of antiretroviral drug resistance in patients with HIV-1 primary infection and in anti retroviral-naive chronically infected patients in 2001-2002

Objective: To survey the frequency of genotypic antiretroviral resistance and the spread of non-B subtypes in patients with primary HIV-1 infection (2001-2002) and in treatment-naive chronically HIV-1-infected patients (2001). Methods: Plasma samples from 303 patients with acute HIV-1 infection (Primo study)and 363 treatment-naive patients with chronic HIV-1 infection (Odyssee study) were tested for genotypic resistance. Resistance mutations were identified from the International AIDS Society Resistance Testing-USA panel and resistant viruses were defined according to the French Agence Nationale de Recherches sur le SIDA (ANRS) resistance algorithm. Results: In the Primo study, 14% of the patients had viruses with resistance mutations and 12% of patients had viruses with mutations conferring resistance to least I antiretroviral drug. Thirty patients had viruses with mutations to at least I antiretroviral drug in a single pharmacologic class. Six patients were infected by viruses resistant to 2 or 3 classes of drugs. In the Odyssee study, the prevalence of reverse transcript (RT) associated and major protease inhibitor-associated mutations was 6.1% (95% CI: 3.6-8.6). Six patients had viruses resistant to at least I antiretroviral drug and 3 patients had viruses resistant to 2 classes of antiretroviral drugs. Twenty-four percent of acutely infected patients harbored non-B subtype strains (19% in 1999-2000) and 33.2% of chronically infected patients (10% in 1998; P < 0.0001). Conclusion: In France, the frequency of HIV-1 resistance in untreated patients was not significantly higher in 2001-2002 than in previous surveys while the prevalence of non-B subtypes is increasing.