Seven paediatric HIV cohorts participating in the European Pregnancy and Paediatric HIV Cohort Collaboration (EPPICC) as follows: French Perinatal Cohort Study / Enquête Périnatale Français; Hospital St.Pierre Cohort, Brussels; Italian Register for HIV-infection in Children; Madrid Cohort of HIV-infected Children; Spanish Perinatal Cohort Study [NENEXP], Catalonia, Spain; UK National Study of HIV in Pregnancy and Childhood [NSHPC] & Collaborative HIV Paediatric Study [CHIPS]; and the "Victor Babes" Hospital Cohort, Romania.