Poverty, dirt, infections and non-atopic wheezing in children from a Brazilian urban center.
BACKGROUND
The causation of asthma is poorly understood. Risk factors for atopic and non-atopic asthma may be different. This study aimed to analyze the associations between markers of poverty, dirt and infections and wheezing in atopic and non-atopic children.


METHODS
1445 children were recruited from a population-based cohort in Salvador, Brazil. Wheezing was assessed using the ISAAC questionnaire and atopy defined as allergen-specific IgE ≥ 0.70 kU/L. Relevant social factors, environmental exposures and serological markers for childhood infections were investigated as risk factors using multivariate multinomial logistic regression.


RESULTS
Common risk factors for wheezing in atopic and non-atopic children, respectively, were parental asthma and respiratory infection in early childhood. No other factor was associated with wheezing in atopic children. Factors associated with wheezing in non-atopics were low maternal educational level (OR 1.49, 95% CI 0.98-2.38), low frequency of room cleaning (OR 2.49, 95% CI 1.27-4.90), presence of rodents in the house (OR 1.48, 95% CI 1.06-2.09), and day care attendance (OR 1.52, 95% CI 1.01-2.29).


CONCLUSIONS
Non-atopic wheezing was associated with risk factors indicative of poverty, dirt and infections. Further research is required to more precisely define the mediating exposures and the mechanisms by which they may cause non-atopic wheeze.
Instituto de Saúde Coletiva, Universidade Federal da Bahia, Salvador, Brazil. mauricio@ufba.br
Mauricio L
ML
Barreto
Sergio S
SS
Cunha
Rosemeire
R
Fiaccone
Renata
R
Esquivel
Leila D
LD
Amorim
Sheila
S
Alvim
Matildes
M
Prado
Alvaro A
AA
Cruz
Philip J
PJ
Cooper
Darci N
DN
Santos
Agostino
A
Strina
Neuza
N
Alcantara-Neves
Laura C
LC
Rodrigues
D001249:Asthma / Q000453:epidemiology*; D001938:Brazil / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D015897:Comorbidity; D005260:Female; D006801:Humans; D006920:Hygiene; D006969:Hypersensitivity, Immediate / Q000453:epidemiology*; D008297:Male; D011204:Poverty Areas; D015995:Prevalence; D012135:Respiratory Sounds; D012141:Respiratory Tract Infections / Q000453:epidemiology*; D018570:Risk Assessment; D012307:Risk Factors; D014505:Urban Population / Q000706:statistics & numerical data*