Today similar first-line treatment choices are made by Ugandan and Swiss physicians, but monitoring strategies still differ. As in other countries of sub-Saharan Africa, treatment of HIV-infected patients is monitored immunologically and clinically, while viral load measurement is reserved for selected patients. In accordance with WHO recommendations treatment failure is therefore determined clinically (new or recurrent WHO stage III or IV condition) and/or by the decline of a patient's CD4 cell count to or below baseline, which usually occurs late during insufficient treatment. Viral rebound and emergence of resistance may thereby arise. Moreover, misclassification of treatment failure (e.g. patients with immunological failure in the absence of virological failure or complete non-adherence to treatment) may result in premature switching to more costly second-line treatment options.