The epidemiology of noncommunicable respiratory disease in sub-Saharan Africa, the Middle East, and North Africa

Noncommunicable diseases (NCDs) are a major and increasing global health issue. The World Health Organization (WHO) estimates that NCDs represent 63% of all global deaths, of which 3.9 million are due to chronic respiratory diseases (CRDs) and chronic obstructive pulmonary disease (COPD) in particular. COPD is now the third most common cause of death globally; 90% of these deaths occur in low-and middle-income countries (LMICs). COPD affects 329 million people-almost 5% of the world's population. In addition, asthma affects 334 million people, again representing almost 5% of the world's population. There is limited literature published on the epidemiology of COPD and asthma from sub-Saharan Africa (SSA) and the Middle East and North Africa (MENA). Both diseases are under-diagnosed and underestimated in both SSA and MENA. The burden of COPD in sub-Saharan Africa is disputed and reports offer variable prevalence estimates, ranging from 4.1% to almost 22.2%. SSA and MENA countries report similar mortality rates from COPD of 18 per 100,000 population (2001 data). Asthma is a less common cause of death than COPD but is a major cause of morbidity; WHO estimates that there are 250,000 deaths per year from asthma, mainly in LMICs, and it remains in the top 20 causes of disability in children globally. Risk factors for CRDs are genetic and environmental; the latter dominated by air pollution exposures, including tobacco smoke, household air pollution, outdoor air pollution, and occupational exposures.