ORIGINAL ARTICLES   

Minerva Pediatrica 2011 February;63(1):19-26

Copyright © 2011 EDIZIONI MINERVA MEDICA

language: English

Environmental exposure to endotoxin in rural and urban Egyptian school children and its relation to asthma and atopy

Morcos M. M. ¹, Morcos W. M. ¹, Ibrahim M. A. ², Shaheen M. A. ² ✉

¹ Child Health Department, National Research Centre, Cairo, Egypt; ² Departments of Pediatrics, Faculty of Medicine, Ain Shams University, Cairo, Egypt

AIM; The environmental exposure of farm children to micro-organisms in dust has been related to a reduced prevalence of asthma and atopy. The aim of this study was to evaluate the relation between settled dust endotoxin and development of asthma and/or atopy in rural and urban school children.
METHODS: A comparative study was conducted on 40 rural and 40 urban school children (6-12 years). Parental self-reported allergic symptoms questionnaires were distributed. Forced expiratory volume in the first second (FEV1), forced vital capacity (FVC) were measured using MIR spirobank and FVE1% was calculated. Skin prick testing with the most common aeroallergens was performed. Limulus amebocyte lysate endotoxin content was measured in settled dust samples.
RESULTS: The rural group which has higher exposure to farm animals and feeding on farm milk has less allergic symptoms. Rural students showed highly significant FEV1, FEV1% and significant FVC versus urban students (110.9±19.7, 103.8±12.2, 105.8±24.3 vs. 92.3±24.2, 98.4±18.9, 92.7±23.2, respectively). Rural school dust contains significantly higher level of endotoxin (2-3 EU/mg) than urban school (0-0.1 EU/mg). Urban residence was associated with increase risk of asthma after age and sex adjustments ([ORadj], 5.16; 95% [CI], 0.95-28).
CONCLUSION: Our results support the hygiene theory, i.e., endotoxin exposure could be protective to asthma and atopy in school children.