The burden of disease attributable to sexually transmitted infections in South Africa in 2000

Objectives. To estimate the burden of disease attributable to sexually transmitted infections (STIs) in South Africa, to identify the factors contributing to this burden, and to review successes and failures in reducing this burden. Design. Years of life lost (YLL) and years lived with disability (YLD) were estimated using different approaches for HIV/AIDS, other STIs and cervical cancer. Burden in respect of HIV/ AIDS was estimated using the ASSA2002 model, and for the other diseases the revised national burden of disease estimates for 2000 based on 1996 cause-of-death data were used. The ASSA2002 model was used to estimate numbers of AIDS deaths under different prevention and treatment scenarios. Setting. South Africa. Outcome measures. Deaths, YLL and disability-adjusted life years (DALYs) associated with HIV/AIDS, other STIs and cervical cancer. Results. STIs accounted for more than 26% of all deaths and over 5 million DALYs in 2000 and over 98% of this burden was due to HIV/AIDS. A combination of social, behavioural and biological conditions contribute to this burden. HIV/AIDS mortality and morbidity are estimated to have increased significantly since 2000, and the future change in this burden is largely dependent on the extent to which antiretroviral treatment and HIV prevention programmes are introduced. 2.5 million AIDS deaths could be prevented by 2015 if high levels of access to antiretroviral treatment are achieved. Conclusion. South Africa faces one of the largest STI epidemics in the world. A multifaceted strategy to prevent and treat STIs is needed, and burden of disease assessments should look beyond the role of ‘unsafe sex’ when attributing this disease burden to risk factors

Estimating the burden of disease attributable to childhood and maternal undernutrition in South Africa in 2000

Objectives. To estimate the disease burden attributable to being underweight as an indicator of undernutrition in children under 5 years of age and in pregnant women for the year 2000. Design. World Health Organization comparative risk assessment (CRA) methodology was followed. The 1999 National Food Consumption Survey prevalence of underweight classified in three low weight-for-age categories was compared with standard growth charts to estimate population-attributable fractions for mortality and morbidity outcomes, based on increased risk for each category and applied to revised burden of disease estimates for South Africa in 2000. Maternal underweight, leading to an increased risk of intra-uterine growth retardation and further risk of low birth weight (LBW), was also assessed using the approach adopted by the global assessment. Monte Carlo simulation-modelling techniques were used for the uncertainty analysis. Setting. South Africa. Subjects. Children under 5 years of age and pregnant women. Outcome measures. Mortality and disability-adjusted life years (DALYs) from protein- energy malnutrition and a fraction of those from diarrhoeal disease, pneumonia, malaria, other non- HIV/AIDS infectious and parasitic conditions in children aged 0 - 4 years, and LBW. Results. Among children under 5 years, 11.8% were underweight. In the same age group, 11 808 deaths (95% uncertainty interval 11 100 - 12 642) or 12.3% (95% uncertainty interval 11.5 - 13.1%) were attributable to being underweight. Protein-energy malnutrition contributed 44.7% and diarrhoeal disease 29.6% of the total attributable burden. Childhood and maternal underweight accounted for 2.7% (95% uncertainty interval 2.6 - 2.9%) of all DALYs in South Africa in 2000 and 10.8% (95% uncertainty interval 10.2 - 11.5%) of DALYs in children under 5. Conclusions. The study shows that reduction of the occurrence of underweight would have a substantial impact on child mortality, and also highlights the need to monitor this important indicator of child health. South African Medical Journal Vol. 97 (8) Part 2 2007: pp. 733-73

Estimating the burden of disease attributable to smoking in South Africa in 2000

Objectives. To quantify the burden of disease attributable to smoking in South Africa for 2000. Design. The absolute difference between observed lung cancer death rate and the level in non-smokers, adjusted for occupational and indoor exposure to lung carcinogens, was used to estimate the proportion of lung cancer deaths attributable to smoking and the smoking impact ratio (SIR). The SIR was substituted for smoking prevalence in the attributable fraction formula for chronic obstructive pulmonary disease (COPD) and cancers to allow for the long lag between exposure and outcome. Assuming a shorter lag between exposure and disease, the current prevalence of smoking was used to estimate the population-attributable fractions (PAF) for the other outcomes. Relative risks (RR) from the American Cancer Society cancer prevention study (CPS-II) were used to calculate PAF. Setting. South Africa. Outcome measures. Deaths and disability-adjusted life years (DALYs) due to lung and other cancers, COPD, cardiovascular conditions, respiratory tuberculosis, and other respiratory and medical conditions. Results. Smoking caused between 41 632 and 46 656 deaths in South Africa, accounting for 8.0 - 9.0% of deaths and 3.7 - 4.3% of DALYs in 2000. Smoking ranked third (after unsafe sex/sexually transmitted disease and high blood pressure) in terms of mortality among 17 risk factors evaluated. Three times as many males as females died from smoking. Lung cancer had the largest attributable fraction due to smoking. However, cardiovascular diseases accounted for the largest proportion of deaths attributed to smoking. Conclusion. Cigarette smoking accounts for a large burden of preventable disease in South Africa. While the government has taken bold legislative action to discourage tobacco use since 1994, it still remains a major public health priority