Risk factors for wheezing in primary health care settings in the tropics

Background The "International Study of Wheezing in Infants (EISL)", is a cross-sectional, population-based study, based on ISAAC. "(Http // www.isaac.auckland.ac.nz ). It uses a validated questionnaire on early wheezing and risk/protective factors. Objective To apply EISL questionnaire regarding wheezing events in 0-12months' infants with/without atopic background searching for risk-factors in the tropics. Methods Population: toddlers coming in for check-up or 12-months’ vaccination in primary health care clinics of a tropical city. Apart from child factors (i.e. day-care attendance) we evaluated home factors (i.e. air-conditioning, bathroom, carpet, >6 persons, pollution) and mother’s factors (i.e. education level, employment, cellphone). Data analysis was descriptively and case-control, with as cases atopic (AW) or nonatopic (NAW) wheezing children versus healthy controls. Wheezing-associated factors were evaluated using multivariate analysis, adjusted for the relation of AW/NAW with factors, significant in prior univariate analysis. Results 999 included toddlers. Any wheeze: 31.3%, recurrent wheeze (≥3 episodes): 12.1%. Major risk-factors for AW (OR;95%CI): smoking (11.39;2.36-54.99), common cold 1 sibling (0.33;0.18-0.61) and breastfeeding >3m (0.50;0.28-0.91) protective. Conclusion Wheezing is a health care burden. We found potential new risk-factors for AW, some possibly unique for tropical climates. We suggest testing several hypotheses: could early AW be reduced in the tropics attacking mold growth? enhancing cooking place ventilation? keeping pets outside? Or by postponing day-care attendance till after four months and avoiding (passive) smoking during pregnancy?