Objective: An AIDS epidemic among older children and adolescents is clinically apparent in Southern Africa. We estimated the likely scale and time course of the epidemic in older survivors of vertical HIV infection.
Design: We modelled demographic, HIV prevalence, mother-to-child transmission and child survival data to project HIV burden among older children in two Southern African countries at different stages of severe HIV epidemics. Using measured survival data for children, we estimate that 64% of HIV-infected infants are fast progressors with median survival 0.64 years and 36% are slow progressors with median survival 16.0 years. We confirmed model validity by comparing model predictions to available epidemiological data.
Findings: Without treatment, HIV prevalence among 10-year-olds in South Africa is expected to increase from 2.1% in 2008 to 3.3% in 2020, whereas in Zimbabwe, it will decrease from 3.2% in 2008 to 1.6% in 2020. Deaths among untreated slow progressors will increase in South Africa from 7000/year in 2008 to 23 000/year in 2030, and in Zimbabwe from 8000/year in 2008 to peak at 9700/year in 2014. Drugs to prevent mother-to-child transmission could reduce death rate in 2030 to 8700/year in South Africa and to 2800/year in Zimbabwe in 2014.
Conclusions: A substantial epidemic of HIV/AIDS in older survivors of mother-to-child transmission is emerging in Southern Africa. The lack of direct observations of survival in slow progressors has resulted in failure to anticipate the magnitude of the epidemic and to adequately address the clinical needs of HIV-infected older children and adolescents. Better HIV diagnostic and care services for this age group are urgently required.
aDepartment of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
bBiomedical Research and Training Institute, Zimbabwe
cDepartment of Medicine, University of Zimbabwe, Harare, Zimbabwe
dDesmond Tutu HIV Centre, University of Cape Town, Cape Town, South Africa
eSouth African Centre for Epidemiological Modelling and Analysis (SACEMA), Stellenbosch, South Africa
fUniversity College London, London, UK
gJoint United Nations Programme on HIV/AIDS (UNAIDS), Geneva, Switzerland.
Received 13 March, 2009
Revised 16 June, 2009
Accepted 25 June, 2009
Correspondence to Dr Rashida Ferrand, Clinical Research Unit, Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK.