Prevalence of asthma among African children and adolescents: findings from the Chronic Respiratory Disease Observatory for Africa (CHEST-Africa).

Abstract

Asthma prevalence is rising in Africa; yet reliable and contemporary prevalence data are unavailable for many countries. Moreover, prevalence estimates are typically based on symptom questionnaires, which may lead to misclassification of disease burden. This study aims to determine the prevalence, severity and treatment of asthma among African children and adolescents from four African countries using both symptom-based and diagnostic testing. We conducted a cross-sectional, school-based study among children aged 6-7 years and adolescents aged 13-14 years using standardised questionnaires. Participants with self-reported asthma (wheeze in the last 12 months and/or ever asthma) underwent spirometry and fractional exhaled nitric oxide testing. Objectively confirmed asthma was defined as self-reported asthma with at least one consistent diagnostic test. A total of 4477 participants' data (2108 children and 2369 adolescents) were analysed. The prevalence of current wheeze was 7.2% in children and 4.3% in adolescents, while self-reported asthma was 8.1% and 4.8% respectively. Over half of the children (54.7%) and adolescents (61.4%) with self-reported asthma reported severe symptoms and 22.4% and 20.2%, respectively, had a prior diagnosis. Objective testing supported asthma in 41.6% of children and 61.0% of adolescents with self-reported asthma. Fewer than 5% of those with self-reported asthma used inhaled corticosteroids. There is substantial underdiagnosis and undertreatment of asthma among African children and adolescents, with high rates of severe symptoms. Incorporating objective testing refines prevalence estimates, underscoring the need to integrate these tests into clinical and epidemiological practice to improve diagnostic accuracy.