High prevalence of asthma symptoms in Warao Amerindian children in Venezuela is significantly associated with open-fire cooking: a cross-sectional observational study

Stèphan Kraai,Berenice Del Nogal,Peter Wm Hermans,Lilly M Verhagen,Jacobus H De Waard,Enrique Valladares,Joaquin Goecke,Paula Colmenares,Lorena Rasquin

doi:10.1186/1465-9921-14-76

Abstract

BackgroundThe International Study on Asthma and Allergies in Childhood (ISAAC) reported a prevalence of asthma symptoms in 17 centers in nine Latin American countries that was similar to prevalence rates reported in non-tropical countries. It has been proposed that the continuous exposure to infectious diseases in rural populations residing in tropical areas leads to a relatively low prevalence of asthma symptoms. As almost a quarter of Latin American people live in rural tropical areas, the encountered high prevalence of asthma symptoms is remarkable. Wood smoke exposure and environmental tobacco smoke have been identified as possible risk factors for having asthma symptoms.MethodsWe performed a cross-sectional observational study from June 1, 2012 to September 30, 2012 in which we interviewed parents and guardians of Warao Amerindian children from Venezuela. Asthma symptoms were defined according to the ISAAC definition as self-reported wheezing in the last 12 months. The associations between wood smoke exposure and environmental tobacco smoke and the prevalence of asthma symptoms were calculated by means of univariate and multivariable logistic regression analyses.ResultsWe included 630 children between two and ten years of age. Asthma symptoms were recorded in 164 of these children (26%). The prevalence of asthma symptoms was associated with the cooking method. Children exposed to the smoke produced by cooking on open wood fires were at higher risk of having asthma symptoms compared to children exposed to cooking with gas (AOR 2.12, 95% CI 1.18 - 3.84). Four percent of the children lived in a household where more than ten cigarettes were smoked per day and they had a higher risk of having asthma symptoms compared to children who were not exposed to cigarette smoke (AOR 2.69, 95% CI 1.11 - 6.48).ConclusionOur findings suggest that children living in rural settings in a household where wood is used for cooking or where more than ten cigarettes are smoked daily have a higher risk of having asthma symptoms.

Highlights

The International Study on Asthma and Allergies in Childhood (ISAAC) reported a prevalence of asthma symptoms in 17 centers in nine Latin American countries that was similar to prevalence rates reported in non-tropical countries
Seventeen centers in nine different Latin American countries participated in the International Study of Asthma and Allergies in Childhood (ISAAC) Phase One [1,2], aimed at reporting the prevalence of respiratory symptoms related to asthma
High prevalence rates of asthma symptoms in children from poor Latin American families were observed in the ISAAC study [3], suggesting that other factors play a role in the development of asthma symptoms

Summary

Introduction

The International Study on Asthma and Allergies in Childhood (ISAAC) reported a prevalence of asthma symptoms in 17 centers in nine Latin American countries that was similar to prevalence rates reported in non-tropical countries. In 1989, Strachan was the first scientist to propose a relationship between asthma and exposure to infectious agents He observed that the allergic disease hay fever was less common in children from larger families compared with families with only one child. He suggested that exposure to infectious agents protects against the development of hay fever [9]. High prevalence rates of asthma symptoms in children from poor Latin American families were observed in the ISAAC study [3], suggesting that other factors play a role in the development of asthma symptoms

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Conclusion