Prevalence of atopy, asthma and COPD in an urban and a rural area of an African country

Abstract

The objectives of this study were to determine the prevalence of asthma, atopy and COPD in Rwanda and to identify risk factors. The survey was conducted in Kigali, the Capital of Rwanda, and in Huye District, a rural area located in southern Rwanda.

Methods: A total of 2138 subjects were invited to participate in the study.1920 individuals (90%) answered to questionnaires on respiratory symptoms and performed spirometry, 1824 had acceptable spirograms and performed skin-prick test. In case of airflow obstruction (defined as pre-bronchodilator ratio FEV(1)/FVC < LLN) a post bronchodilator spirometry was performed. Reversibility was defined as an increase in FEV(1) of 200 ml and 12% above baseline FEV(1) after inhalation of 400 mcg of salbutamol.

Results: The mean age was 38.3 years; 48.1% of participants were males and 51.9% females. Airflow obstruction was found in 256 participants (14%); 163(8.9%) subjects were asthmatics and 82 (4.5%) had COPD. COPD was found in 9.6% of participants aged 45 years and above. 484 subjects had positive skin-prick tests (26.5%); house dust mite and grass pollen mix were the main allergens. Risk factors for asthma were allergy, female gender and living in Kigali. COPD was associated with cigarette smoking, age and male sex.

Conclusion: this is the first study which shows the prevalence of atopy, asthma and COPD in Rwanda. Asthma and COPD were respectively diagnosed in 8.9% and 4.5% of participants. COPD was diagnosed in 9.6% of subjects aged ≥ 45 years.The prevalence of asthma was higher in urban compared to rural area.