Prevalence of symptoms of asthma, rhinitis and eczema in 13‐ to 14‐year‐old children in Africa: the International Study of Asthma and Allergies in Childhood Phase III

Abstract

Phase I of the International Study of Asthma and Allergies in Childhood has provided valuable information regarding international prevalence patterns and potential risk factors in the development of asthma, allergic rhinoconjunctivitis and eczema. However, in Phase I, only six African countries were involved (Algeria, Tunisia, Morocco, Kenya, South Africa and Ethiopia). Phase III, conducted 5–6 years later, enrolled 22 centres in 16 countries including the majority of the centres involved in Phase I and new centres in Morocco, Tunisia, Democratic Republic of Congo, Togo, Sudan, Cameroon, Gabon, Reunion Island and South Africa. There were considerable variations between the various centres of Africa in the prevalence of the main symptoms of the three conditions: wheeze (4.0–21.5%), allergic rhinoconjunctivitis (7.2–27.3%) and eczema (4.7–23.0%). There was a large variation both between countries and between centres in the same country. Several centres, including Cape Town (20.3%), Polokwane (18.0%), Reunion Island (21.5%), Brazzaville (19.9%), Nairobi (18.0%), Urban Ivory Coast (19.3%) and Conakry (18.6%) showed relatively high asthma symptom prevalences, similar to those in western Europe. There were also a number of centres showing high symptom prevalences for allergic rhinoconjunctivitis (Cape Town, Reunion Island, Brazzaville, Eldoret, Urban Ivory Coast, Conakry, Casablanca, Wilays of Algiers, Sousse and Eldoret) and eczema (Brazzaville, Eldoret, Addis Ababa, Urban Ivory Coast, Conakry, Marrakech and Casablanca).

Pediatric Asthma in Southern Africa

“…Polokwane, in the north of South Africa, participated in the ISAAC protocol, documenting a prevalence of both asthma and allergic rhinitis in this area almost as high as in Cape Town [12]. The most important result of this study is that it confirmed a high ongoing prevalence of allergic conditions in the north of South Africa.…”

“…This means that we can use this together with the data from Cape Town, to suggest a prevalence for all of South Africa. The prevalence of asthma symptoms in Polokwane was 18%; not dissimilar to the 20,7% in Cape Town [12].…”

The impact of asthma and COPD in sub-Saharan Africa

“…17,31 The prevalence of asthma varies widely between countries: Ethiopia 9.1%, Kenya 15.8%, Nigeria 13.0%, Mozambique 13.3%, and South Africa 20.3%. 24,32 Asthma appears to be more severe in sub-Saharan Africa than in affluent countries, although the latter have the highest symptom prevalence. 32,33 In countries where several centres are involved in surveys, the prevalence of asthma is generally highest in urban areas.…”

“…In urban areas which have become increasingly 'westernised', the prevalence is higher and is similar to European countries. 24 Owing to the projected increase in the urban population in sub-Saharan Africa, it is estimated that there may be an increase of at least 35% in the number of people with asthma by 2025. 21 In developed countries children under the age of 15 years represent approximately 20% of the population, whereas in sub-Saharan Africa these children form approximately half of the population.…”

“…17 Eleven surveys of the prevalence of asthma in sub-Saharan Africa were identified and are listed in Table 1. 17,20,[22][23][24][25][26][27][28][29][30] People living in rural grasslands rarely if ever suffer from allergic diseases and most of the local languages do not even have words to describe these conditions. 17,31 The prevalence of asthma varies widely between countries: Ethiopia 9.1%, Kenya 15.8%, Nigeria 13.0%, Mozambique 13.3%, and South Africa 20.3%.…”