The Virological and Immunological Characteristics of the HIV-1-Infected Population in Brazil: From Initial Diagnosis to Impact of Antiretroviral Use

Background Immunological and virological status of HIV-infected individuals entering the Brazilian public system over time was analyzed. We evaluated the impact of ART on virological, immunological and antiretroviral resistance over time. Methods CD4+ T cell counts, viral loads and genotypes from patients over 13 years old from 2001–2011 were analyzed according to demographic data. We compared groups using parametric t-tests and linear regression analysis in the R statistical software language. Results Mean baseline CD4+ T cell counts varied from 348 (2003) to 389 (2009) and was higher among women (p = 1.1 x 10 −8 ), lower in older patients (p< 1 x 10 −8 ) and lower in less developed regions (p = 1.864 x 10 −5 ). Percentage of treated patients with undetectable viral loads increased linearly from 46% (2001) to 77% (2011), was lower among women (p = 2.851 x 10 −6 ), younger ages (p = 1 x 10 −3 ), and in less developed regions (p = 1.782 x 10 −4 ). NRTI acquired resistance was 86% in 2001–3 and decreased over time. NNRTI resistance increased from 2001-3(50%) to 2006–9 (60%), PI resistance decreased from 2001–3 (60%) to 2009 (40%), and 3-class resistance was stable over time around 25%. Subtype prevalence comprised B (75.3%), B/F recombinants (12.2%), C (5.7%), F (5.3%) and B/C recombinants (1.5%), with regional variations. Three-class resistance was 26.5% among Bs, 22.4% among Fs and 17.2% among Cs. Conclusions HIV diagnosis occurs late, especially among elderly Brazilians. Younger individuals need special attention due to poor virological response to treatment. Antiretroviral Resistance profile is subtype related.