Worldwide more than three million children are infected with HIV 90 of whom live in sub-Saharan Africa. cause severe morbidity. As well as dealing with chronic illness HIV-infected adolescents have to confront psychosocial issues maintain adherence to drugs and learn to negotiate sexual relationships while undergoing rapid physical and psychological development. Context-specific strategies for early identification of LY310762 HIV contamination in children and prompt linkage to care need to be developed. Clinical HIV care should integrate age-appropriate sexual and reproductive health and psychological educational and social services. Health-care workers will need to be trained LY310762 to recognise and manage the needs of these young people so that LY310762 the increasing numbers of children surviving to adolescence can access quality care beyond specialist services at low-level health-care facilities. Introduction HIV contamination has been established for more than 30 years with sub-Saharan Africa continuing to have the highest incidence of HIV of any region.1 The global epidemiology of paediatric HIV mirrors that of adults. Of more than three million children infected with HIV 90 live in sub-Saharan Africa.1 The advent of the HIV epidemic resulted in a reversal of the improvements recorded in child health outcomes in the 1970s and 1980s with global child mortality rates a third to two-thirds higher than they would have been in the absence of HIV/AIDS.2 However since 2004 access to paediatric antiretroviral treatment has expanded globally resulting in a substantial decline in mortality rates in HIV-infected children.3 In view of this increased survival HIV is now evolving into a chronic illness among adolescents.4 Young adults GABPB2 who have grown up with HIV present an important challenge to HIV care programmes. Longstanding HIV contamination acquired when the immune system was not developed results in distinctive chronic clinical complications that cause severe morbidity. In addition to dealing with chronic illness HIV-infected adolescents have to confront psychosocial issues maintain adherence to drugs and learn to negotiate sexual relationships while undergoing rapid physical and psychological changes.5 In this Review we discuss the evolving epidemiology of paediatric HIV infection and the shift of the infection burden onto adolescents. We also consider some of the unique features that characterise HIV contamination in survivors of perinatally acquired HIV contamination. The ageing paediatric HIV epidemic Unlike the rapid widespread implementation of highly effective HIV interventions in industrialised countries that began in the mid 1990s antiretroviral treatment for prevention of mother-to-child HIV transmission only became available in much of Africa around 2004. Although in sub-Saharan Africa the number of infant infections has decreased by 24% from 2009 to 2011 treatment coverage remains suboptimum with only 59% of HIV-infected pregnant women receiving antiretroviral treatment to prevent mother-to-child transmission in the 21 high-burden countries and about 1000 LY310762 infants were infected daily in 2011.1 Before antiretroviral treatment was available HIV-infected infants in Africa had a 50% LY310762 probability of dying by age 2 years.6 The increasing availability of antiretroviral drugs has resulted in a substantial rise in the life expectancy of children living with HIV in low-income countries so that escalating numbers of children are surviving to adolescence and beyond.7 8 For example more than 40% of the 25 000 children in HIV care in Zimbabwe in 2009 2009 were age 10 years or older.9 However the large numbers of adolescents in HIV programmes in sub-Saharan Africa are not accounted for fully by raised survival related to antiretroviral treatment. Over the past decade substantial numbers of children in sub-Saharan Africa with perinatally acquired HIV have been presenting to health-care services for the first time during adolescence.10 11 By extrapolation of high early mortality rates associated with untreated HIV in the early days of the HIV epidemic the widely held perception was that.