Farming exposure in childhood, exposure to markers of infections and the development of atopy in rural subjects
Article first published online: 9 JUL 2004
Clinical & Experimental Allergy
Volume 34, Issue 8, pages 1178–1183, August 2004
How to Cite
Radon, K., Windstetter, D., Eckart, J., Dressel, H., Leitritz, L., Reichert, J., Schmid, M., Praml, G., Schosser, M., Von Mutius, E. and Nowak, D. (2004), Farming exposure in childhood, exposure to markers of infections and the development of atopy in rural subjects. Clinical & Experimental Allergy, 34: 1178–1183. doi: 10.1111/j.1365-2222.2004.02005.x
- Issue published online: 9 JUL 2004
- Article first published online: 9 JUL 2004
- Submitted 24 November 2003; revised 17 March 2004; accepted 27 April 2004
- animal farming;
- field crop;
- Helicobacter pylori;
- hygiene hypothesis;
- Toxoplasma gondii;
- unpasteurized milk
Background Within the context of the hygiene hypothesis, we aimed to study the potential association between farming-related risk factors and Toxoplasma gondii (T. gondii) as well as Helicobacter pylori (H. pylori) seropositivity.
Methods The study included questionnaire data and serum samples of 321 young adults living in a rural environment. Serum samples were analysed for specific IgE to a common panel of aeroallergens (SX1) as well as IgG against T. gondii and H. pylori.
Results Regular contact with animal stables before the age of 3 years (odds ratio (OR) (95% confidence interval): 2.0 [1.0; 4.0]) and unpasteurized milk consumption at age 6 years (1.8 [1.0; 3.3]) were the strongest risk factors for T. gondii infection. None of the farming-related factors were significantly associated with H. pylori infection. Current consumption of raw farm milk was not significantly associated with H. pylori infection (2.1 [0.8; 5.3]). Regular contact with animal houses before the age of 7 years was the strongest predictor for atopy (0.49 [0.26–0.96]). The reduction in risk could not be further decreased by any other factor under consideration. After adjustment for animal house contact, the OR for atopy was decreased by raw milk consumption and H. pylori infection in an additive manner.
Conclusion Exposure to farming environments in childhood might predict T. gondii seropositivity in rural subjects. Nevertheless, the strongest predictor for atopy in rural subjects seems to be regular contact with farm animals. Whether T. gondii infection is an intermediate factor in the association between farm contact and atopy needs to be confirmed in larger studies.