Prevalence of asthma among school children in Gaborone, Botswana.

Background: Asthma prevalence is high (>10%) in developed countries and although data is still missing for most of Africa, rates are increasing in developing regions as they become more westernized. We investigated the prevalence of asthma in school children in Gaborone, Botswana.
Methods: This was a cross sectional descriptive study. ISAAC methodology was used. A representative proportionate size random sample of two age groups of children (13-14 year olds and 6-7 year olds) was consecutively enrolled from 10 schools. The schools were selected using a table of random numbers. A minimum sample size of 924 individuals (462 from each group) was adequate to achieve a precision of 3 % around our estimated prevalence of asthma of 10% with 95% confidence assuming a non-response rate of 20%. Data was collected using the validated International study of Asthma and Allergies in children (ISAAC) questionnaire. In accordance with the ISAAC criteria, Asthma was defined as wheezing in the previous 12 months. Data was captured in microsoft excel and analysed using SPSS version 23.
Results: The prevalence of asthma (wheezing in the previous 12 months) was 16.5% (194/1175). Among the 6-7 year olds, the prevalence of asthma (wheezing in the previous 12 months) was 15.9%, while among the 13-14 years olds it was 16.8 %. The prevalence school type was 22.3 % in private schools versus 14.5 % in public schools. More severe asthma was associated with older children, 13 -14 years. The older children reported more limited speech due to wheezing (OR= 2.0, 95% CI =1.034, 3.9, p-value=0.043), ever had asthma (OR= 1.5, 95% CI=1.031, 2.3, p-value=0.034) and wheezing during exercise (OR=3.4, 95% CI= 2.5, 4.9, p-value= <0.001) compared to the younger children 6-7 years. Children from private schools had more wheezing symptoms. They were more likely to have ever wheezed (OR=2.2, .95% CI=1.7,2.9, p-value < 0.0001), wheezed in the previous twelve months (have asthma) (OR=1.7,95%CI=1.2,2.4, p-value = 0.001), ever had asthma (OR=2.4, 95% CI=1.7,3.5, pvalue< 0.0001), and wheezed during exercise (OR=1.8, 95% CI=1.4,2.4, p-value < 0.0001).
Conclusion: The prevalence of asthma amongst school children in Gaborone, Botswana is high with older children experiencing more severe symptoms of asthma.