A Multicentre Trial of Second-line Antiretroviral Treatment Strategies in African Adults Using Atazanavir or Lopinavir/Ritonavir

Inclusion Criteria: * age 18 and above * out patient * documented HIV-1 infection * first line treatment failure: * after first-line antiretroviral treatment with a combination including a non-nucleoside reverse transcriptase inhibitor and two nucleoside reverse transcriptase inhibitors * two measurements of plasma HIV RNA levels \> 1000 copies/mL after at least 6 months of uninterrupted treatment or without any major modification * satisfactory compliance (\>80%) to 1st line antiretroviral treatment * signed informed consent * agreement for contraception for women of childbearing age Exclusion Criteria: * HIV-2 infection or HIV-1/HIV-2 coinfection * uncontrolled, ongoing opportunistic infection or of any severe or progressive disease including active TB * first line antiretroviral treatment with a protease inhibitor or tenofovir * ongoing treatment with rifampicin * severe hepatic insufficiency (PT \< 50%) * ALT \< 3 times the upper limit of normal * creatinine clearance calculated by Cockcroft's formula \< 50 mL/min * Hb \<=8 g/dL; platelets \< 50,000 cells/mm3; neutrophils \< 500 cells/mm3 * pregnancy and lactation