Estimating the burden of disease attributable to vitamin A deficiency in South Africa in 2000
Objectives. To estimate the burden of disease attributable to vitamin A deficiency in children aged 0 - 4 years and pregnant women aged 15 - 49 years in South Africa in 2000. Design. The framework adopted for the most recent World Health Organization comparative risk assessment (CRA) methodology was followed. Population-attributable fractions were calculated from South African Vitamin A Consultative Group (SAVACG) survey data on the prevalence of vitamin A deficiency in children and the relative risks of associated health problems, applied to revised burden of disease estimates for South Africa in the year 2000. Small community studies were used to derive the prevalence in pregnant women. Monte Carlo simulation-modelling techniques were used for the uncertainty analysis. Setting. South Africa. Subjects. Children under 5 years and pregnant women 15 - 49 years. Outcome measures. Direct sequelae of vitamin A deficiency, including disability-adjusted life years (DALYs), as well as mortality associated with measles, diarrhoeal diseases and other infections, and mortality and DALYs associated with malaria in children and all-cause maternal mortality. Results. One-third of children aged 0 - 4 years and 1 - 6% of pregnant women were vitamin A-deficient. Of deaths among young children aged 0 - 4 years in 2000, about 28% of those resulting from diarrhoeal diseases, 23% of those from measles, and 21% of those from malaria were attributed to vitamin A deficiency, accounting for some 3 000 deaths. Overall, about 110 467 (95% uncertainty interval 86 388 - 136 009) healthy years of life lost, or between 0.5% and 0.8% of all DALYs in South Africa in 2000 were attributable to vitamin A deficiency. Conclusions. The vitamin A supplementation programme for children and the recent food fortification programme introduced in South Africa in 2003 should prevent future morbidity and mortality related to vitamin A deficiency. Monitoring the effectiveness of these interventions is strongly recommended.