ODYSSEY (PENTA 20)

Inclusion Criteria: ALL PATIENTS: * Children ≥28 days and \<18 years weighing ≥3kg with confirmed HIV-1 infection * Parents/carers and children, where applicable, give informed written consent * Girls aged 12 years or older who have reached menses must have a negative pregnancy test at screening and be willing to adhere to effective methods of contraception if sexually active * Children with co-infections who need to start ART can be enrolled into ODYSSEY according to local/national guidelines * Parents/carers and children, where applicable, willing to adhere to a minimum of 96 weeks' follow-up * Children weighing 3 to \<14kg must be eligible and willing to participate in the Weight band (WB)-Pharmacokinetics (PK)1 substudy unless direct enrolment for the child's weight band has opened following the WB-PK1 substudy and/or dosing information has become available from the IMPAACT P1093 DTG dose-finding study. ADDITIONAL CRITERIA FOR ODYSSEY A: • Planning to start first-line ART ADDITIONAL CRITERIA FOR ODYSSEY B: * Planning to start second-line ART defined as either: (i) switch of at least 2 ART drugs due to treatment failure; or (ii) switch of only the third agent due to treatment failure where drug sensitivity tests show no mutations conferring Nucleoside Reverse Transcriptase Inhibitor (NRTI) resistance * Treated with only one previous ART regimen. Single drug substitutions for toxicity, simplification, changes in national guidelines or drug availability are allowed …