Impact of biomass fuel smoke on respiratory health of children under 15 years old in Madagascar.

BACKGROUND: Children exposed to biomass used in households are at risk to develop diseases or respiratory symptoms. In Madagascar more than 95% of households use it daily. The main objective is to study the impact of chronic exposure to biomass on respiratory health of children under 15 years old in Madagascar. METHODS: Descriptive cross-sectional study conducted with questionnaires among urban and rural population of Antananarivo and Mahajanga provinces between 2016 and 2017. Variables were collected: number of hours spent in kitchen per day, respiratory symptoms and spirometric data. Categorized symptoms score and exposure index expressing chronic exposure to biomass were analyzed with multinomial logistic regression models. RESULTS: Of the 661 children included in the analysis, 27.7% had 1 respiratory symptom and 29.3% had 2 or more respiratory symptoms. Moderate exposure index (aOR=1.57; CI95%=[1.30-1.89]; p<0.001) and high exposure index (aOR=1.76; CI95%=[1.39-2.24]; p<0.001) were significantly associated with 1 respiratory symptom, adjusted with provinces, household members and visitors smoking, perceived discomfort related to air pollution and birthweight. Exposure index was not significantly associated with an increased risk of having 2 or more respiratory symptoms (p = 0.754). CONCLUSION: Respiratory symptoms were associated with exposure to biomass, living in coastal areas, birthweight, tobacco and perceived discomfort related to air pollution. Recommendations and actions must be implemented in order to improve respiratory health related to biomass among children.

High IgE sensitization to maize and rice pollen in the highlands of Madagascar.

INTRODUCTION: Maize and rice are two crops constituting the main food supply in many under-developed and developing countries. Despite the large area devoted to the culture, the sensitization to the pollen from these plants is reported to be low and often considered as an occupational allergy. METHODS: Sixty five Malagasy pollen allergic patients were clinically and immunochemically investigated with regard to maize and rice pollen allergens. Pollen extracts were electrophoretically separated in 1 and 2 dimensions and IgE and IgG reactivities detected upon immunoblotting. RESULTS: When exploring the sensitization profile of Malagasy allergic patients to maize and rice pollen, it appears that a high proportion of these patients consulting during grass pollinating season were sensitized to both pollen as revealed by skin prick testing (62 vs. 59%) and IgE immunoblotting (85 vs. 40%). Several clinically relevant allergens were recognized by patients' serum IgE in maize and rice pollen extracts. CONCLUSION: The high levels of maize and rice pollen sensitization should be related, in this tropical region, to a specific environmental exposure including i) a proximity of the population to the allergenic sources and ii) a putative exacerbating effect of a highly polluted urban atmosphere on pollen allergenicity. Cross-reactivities between wild and cultivated grasses and also between rice and maize pollen are involved as well as some specific maize sensitizations. The presence of dense urban and peri-urban agriculture, in various African regions and worldwide, could be a high environmental risk factor for people sensitive to maize pollen.