The Chilean AIDS cohort: a model for evaluating the impact of an expanded access program to antiretroviral therapy in a middle-income country--organization and preliminary results.

Chile, middle-income country with 15 million people, began an expanded access program (EAP) to antiretroviral therapy (ART) in 2001. EAP provides ART, monitoring, and funding for management of associated complications in 32 points of care. A national cohort (Chilean AIDS Cohort [ChiAC]), enrolling 98% of these patients, was created for standardized treatment and impact evaluation. Information exchange is mainly through the Internet. By December 2004, the ChiAC had 4365 participants (83.3% male). At baseline, 47.5% had clinical AIDS, 26.2% were asymptomatic, 80.2% had a CD4 count <200 cells/mm and 58.2% were ART naive; in these patients, the most frequent regimen is zidovudine, lamivudine, and efavirenz. A 6-month follow-up in 1057 patients showed a global mortality of 5% (0.5% if patients were asymptomatic at baseline and 8.3% if patients had baseline AIDS). There was a similar risk of death if the baseline CD4 count was 100 to 200 cells/mm or >200 cells/mm ( approximately 1%), but this increased to 4.8% (relative risk [RR] = 5.2) and 10.7% (RR = 11.5) if the CD4 count was 51 to 100 cells/mm or

[Primary resistance to antiretroviral therapy in patients with HIV/AIDS in Chile]. / Resistencia primaria a terapia antirretroviral en pacientes con infección por VIH/SIDA en Chile.

BACKGROUND: Resistance to antiretroviral therapy is a determining factor for therapeutic failure in HIV/AIDS. The prevalence of primary resistance (i.e. in those patients that have not received treatment) varies in different parts of the world. AIM: To study the prevalence of primary resistance to antiretroviral drugs in patients living in Northern Santiago. PATIENTS AND METHODS: Viral load, lymphocyte subpopulations by flow cytometry and genotypic resistance testing were assessed in blood samples from 60 HIV-1 infected patients (mean age 37 years, 54 male). RESULTS: Mean CD4 cell count and viral load was 200 cells/ml and 142,840 RNA copies/ml respectively. Ten mutations were identified: V179D, L10I/V, M361, L63P, A71T/V, Y115F, V118I and K20R. None of these mutations is associated to a high degree of resistance to reverse transcriptase inhibitors, nucleoside analogs (NRTI), non nucleoside analogs (NNRTI) or viral protease inhibitors. CONCLUSIONS: This is a first approach to study antiretroviral resistance in Chilean patients. This study must be amplified, since the prevalence of resistance may experience changes with time.