Objectives: To assess the prevalence of an undetectable viral load (VL) (<50 HIV-1 RNA copies/mL) in a clinical population and to identify those viraemic and at risk of failing antiretroviral therapy (ART).
Methods: An audit of a complete clinical population on 1 January 2005 via a clinical database and clinical note review.
Results: On 1 January 2005, 1910 patients were under care; 1229/1332 (92%) of those exposed to ART for >16 weeks had a VL of <50 copies/mL. We examined 49/56 case notes of viraemic patients to identify explanations for viraemia. Common reasons included previous initial mono- or dual therapy, adherence problems, more advanced HIV disease, concomitant medications, physical and mental health issues and being less well linked into the service. A review of these patients' current status on 1 April 2007 showed that six of the 49 had since died. However, of those still alive, 20 (47%) had a VL <500 copies/mL.
Conclusions: The proportion of patients on ART with detectable viraemia is low in current clinical practice. New drugs may help those who are failing because of resistance. However, there is a small minority of patients who, for various reasons, appear unable to maintain sufficient adherence to ART.