Virologic response of treatment experienced HIV-infected Ugandan children and adolescents on NNRTI based first-line regimen, previously monitored without viral load oleh Phionah Kibalama Ssemambo, Mary Gorrethy Nalubega-Mboowa, Arthur Owora, Robert Serunjogi, Susan Kironde, Sarah Nakabuye, Francis Ssozi, Maria Nannyonga, Philippa Musoke, Linda Barlow-Mosha