Comparison of local risk factors for children's atopic symptoms in Hanoi, Vietnam
Article first published online: 14 MAY 2004
Volume 59, Issue 6, pages 637–644, June 2004
How to Cite
Chai, S. K., Nga, N. N., Checkoway, H., Takaro, T. K., Redding, G. J., Keifer, M. C., Trung, L. V. and Barnhart, S. (2004), Comparison of local risk factors for children's atopic symptoms in Hanoi, Vietnam. Allergy, 59: 637–644. doi: 10.1111/j.1398-9995.2004.00463.x
- Issue published online: 14 MAY 2004
- Article first published online: 14 MAY 2004
- Accepted for publication 12 November 2003
- developing countries;
- hay fever perennial allergic rhinitis;
- risk factors
Background: A 1999 study in Hanoi, Vietnam using the International Study on Asthma and Allergies in Childhood (ISAAC) questionnaire showed a high prevalence of atopic symptoms. Identifying risk factors for symptoms in these children may help in understanding the causes for these high estimates.
Methods: An ISAAC questionnaire with supplemental questions on environmental variables was distributed to 5495 school children in Hanoi and a suburban district, Dong Anh. The response rate was 65.7%.
Results: In Dong Anh, the following were among the significant age and gender adjusted associations: pig ownership [odds ratio (OR) (95% confidence interval), OR = 1.79 (1.18–2.70) for doctor-diagnosed asthma (DDA), OR = 1.72 (1.08–2.78) for doctor diagnosed hay fever (DDHF)] and farming [OR = 1.67 (1.27–2.19) for ever asthma, OR = 1.51 (1.09–2.09) for DDHF]. In multivariate models, tuberculosis (TB) was a significant predictor of atopic symptoms [Hanoi: OR = 3.09 (1.10–8.70) for DDA, Dong Anh: OR = 3.71 (1.40–9.84) for DDA, OR = 4.66 (1.88–11.57) for DDHF].
Conclusions: These findings are contrary to the ‘hygiene hypothesis’. Recent immunologic and epidemiologic studies refute the inverse association between allergy and TB and may be one explanation for the positive association in this study. The positive association with pig ownership and farming may be because of exposures on farms in a developing country that may be different from exposures in farms of developed countries.