Article
Effect of urban vs. rural residence on the association between atopy and wheeze in Latin America: findings from a case-control analysis
Registro en:
ENDARA, P. et al. Effect of urban vs. rural residence on the association between atopy and wheeze in Latin America: findings from a case-control analysis. Clinical & Experimental Allergy, v. 45, p. 438-447, 2015.
0954-7894
10.1111/cea.12399
Autor
Endara, P.
Vaca, M.
Platts-Mills, T. A. E.
Workman, L.
Chico, M. E.
Barreto, Maurício Lima
Rodrigues, Laura Cunha
Cooper, P. J.
Resumen
Barreto, Mauricio Lima. Fiundação Oswaldo Cruz. Instituto Gonçalo Moniz. “Documento produzido em parceria ou por autor vinculado à Fiocruz, mas não consta à informação no documento”. Wellcome Trust, UK, HCPC Latin America Centres of Excellence Programme (grant 072405/Z/03/Z); PJC is
supported by the Wellcome Trust (grant 088862/Z/09/Z); and TAEPM is supported by NIH grant AI-20565. The association between atopy and asthma is attenuated in non-affluent populations, an effect that may be explained by childhood infections such as geohelminths. Objective To investigate the association between atopy and wheeze in schoolchildren living
in urban and rural areas of Ecuador and examine the effects of geohelminths on this
association.
Methods We performed nested case–control studies among comparable populations of
schoolchildren living in rural communities and urban neighbourhoods in the Province of
Esmeraldas, Ecuador. We detected geohelminths in stool samples, measured recent wheeze
and environmental exposures by parental questionnaire, and atopy by specific IgE (sIgE)
and skin prick test (SPT) reactivity to aeroallergens.
Results Atopy, particularly sIgE to house dust mite (HDM), was more strongly associated
with recent wheeze in urban than rural schoolchildren: (urban, adj. OR 5.19, 95% CI
3.37–8.00, P < 0.0001; rural, adj. OR 1.81, 95%CI 1.09–2.99, P = 0.02; interaction,
P < 0.001). The population fractions of wheeze attributable to atopy were approximately
two-fold greater in urban schoolchildren: SPT to any allergen (urban 23.5% vs. rural
10.1%), SPT to HDM (urban 18.5% vs. rural 9.6%), and anti-HDM IgE (urban 26.5% vs.
rural 10.5%), while anti-Ascaris IgE was related to wheeze in a high proportion of rural
(49.7%) and urban (35.4%) children. The association between atopy and recent wheeze
was attenuated by markers of geohelminth infections.
Conclusions Our data suggest that urban residence modifies the association between HDM
atopy and recent wheeze, and this effect is explained partly by geohelminth infections.