Virological failure to raltegravir in Spain: incidence, prevalence and clinical consequences

The objective of this study was to evaluate the incidence, prevalence and clinical consequences of virological failure (VF) to raltegravir-based regimens in Spain. A multicentre, retrospective, observational study was performed in 10 tertiary hospitals (January 2006 to June 2013). The study included HIV-1-infected patients with loss of virological suppression (LVS; two consecutive HIV-1 RNA ≥50 copies/mL) while receiving raltegravir. VF and low-level viraemia (LLV) were defined as two consecutive HIV-1 RNA ≥200 copies/mL and 50 to