Asthma in Africa

Asthma in Developing Countries
It has been found that, maybe surprisingly, Asthma is less prevalent in developing countries than developed countries  [1]. Lower rates are found in Asia, Eastern Europe and Africa [2], but they are on the rise [3]. Within developed countries it is more common in those who are economically disadvantage while in contrast in developing countries it is more common in the affluent [1].

Data from the International Study of Asthma and Allergies in Childhood (ISAAC,  http://isaac.auckland.ac.nz) shows that in the seven participating African countries, s ymptom rates are lower than in industrialized countries, while only South Africa approaches rates found in the UK.

" The interpretation of these figures, however, is difficult; there might be an increase with gross domestic product and industrialization factors . Rural African regions always showed much lower asthma prevalence rates than urban areas . People living in rural grasslands rarely, if ever, suffer from allergic diseases and some do not even have a term to describe this condition ." [4]

Associated Risks and Causes
Living in Africa appears to present some risk factors, however, like the rest of the world, there is no overall hypothesis to explain asthma causation in Africa.

"Assumed risk factors are local flora such as Kikuyu grass, Makaore cherry, Tanganyika aningré, and Der néré as well as helminthic infection by  Trichuris,  Schistosoma,  Ascaris, and hookworm <span style="color:rgb(51,51,51);font-family:arial,sans-serif;font-size:13px;line-height:18px;">. Well-known allergens in Africa are house dust mite, cockroach, and cat and dog dander; a less well known allergen is washing soap. Parental history, female sex, low physical activity, and malnutrition, have been described as risk factors together with pesticides, insecticides, wood or kerosene heating, grass mats, mud and cow dung, smoking, and car and truck diesel exhaust. In the occupational setting isocyanate and latex sensitivity have been reported as risk factors, and poultry workers, hairdressers, gold miners, and wood choppers are reported as having an increased risk of asthma. Annual rainfall seems to have an influence on symptom presentation." [4]

It is clear then that there is no clear, single cause of Asthma in Africa, or indeed anywhere. It is also argued though that genetics can be a major cause of the development of Asthma. With diseases arrising from indegestion of unsafe water and other sanitation problems, there is a large number of child deaths, with questions arrising about whether this can also be related to allergies and asthma [4]. More information on host factors such as genetics, and much more can be found in the extensive "Global Strategy for Asthma Management and Prevention".