Commentary: Non-communicable diseases in sub-Saharan Africa: a new global health priority and opportunity.

As part of the updated assessment of the Global Burden of Disease (GBD) study, the World Health Organization (WHO) has provided an overview of the global and regional levels and patterns of causes of death. Based on this assessment, it is estimated that nearly 59 million people died in the world during 2004. Of these deaths, 60% were due to noncommunicable diseases (NCDs) (i.e. Group II conditions), such as cardiovascular disease, diabetes, cancer and metabolic disorders. With only about one-third of the deaths due to communicable diseases, maternal and prenatal conditions and nutritional deficiencies (Group I conditions), there is increasing recognition of the importance of NCDs as a growing contributor of the GBD. Within sub-Saharan Africa, Group I conditions remain an important cause of deaths, although the contribution of NCDs is also increasing. In 2004, Group I conditions accounted for 62% of all deaths among adults aged 15–59 years in this region, whereas cardiovascular diseases, cancer and other Group II conditions contributed for about one-third of the deaths in this age group among both males and females. Within Group I conditions, HIV/AIDS was the main contributor of mortality, accounting for 35% of the overall adult deaths. Thus, if we exclude HIV/ AIDS, the contribution of remaining Group I conditions to the burden of diseases in sub-Saharan Africa is comparable with that of NCDs, which are becoming a significant public health problem in the region. Similar trends have been observed in other lowas well as middle-income countries which, when taken together, are projected to account for 80% of all global deaths due to NCDs by the year 2030. The increasing burden of NCDs in lowand middle-income countries previously dominated by infectious and other Group I conditions suggests that a major epidemiological transition is taking place in these settings. However, the precise burden of NCDs and other chronic conditions, as well as the rate of occurrence of associated morbidity and mortality in most countries remains unknown. This is particularly true in sub-Saharan Africa where health facilities are under-resourced and accurate information about chronic diseases is lacking. In addition, only few patients with NCDs seek medical services, and limited research has been conducted to determine the burden of NCDs and the distribution of potential risk factors in various geographical locations. To help fill this gap in our knowledge, Dalal et al. report in this issue of the IJE a comprehensive review of literature on the burden of NCDs as contributors of morbidity and mortality, as well as the prevalence of associated risk factors. As part of this publication, they searched the PubMed database and included community-based studies conducted in any subSaharan African country, published in English, and reported on the burden or risk factors for four main NCDs: heart diseases, stroke, diabetes mellitus type 2 and cancer. They also analysed publicly available data sets on estimated and projected causes of death from the WHO GBD and the International Agency for Research on Cancer (IARC). The findings of this report provide important insights on the epidemiology of NCDs in Africa and associated risk factors. Overall, NCDs were relatively common in the studies reported, indicating that they are a major public health priority in sub-Saharan Africa. These results confirm that Africa is facing an emerging epidemic of NCDs, which is overlapping with the ongoing burden of infectious diseases. The prevalence of specific conditions and associated risk factors varied from one country to another and also within the same country, indicating that the burden Published by Oxford University Press on behalf of the International Epidemiological Association