title: Investigation of the hygiene hypothesis: current issues and future directions.
authors.forename: A-L
authors.initials: AL
authors.lastname: Ponsonby
authors.forename: A
authors.initials: A
authors.lastname: Kemp
mesh_terms: D000818:Animals; D002675:Child, Preschool; D006801:Humans; D006920:Hygiene; D006969:Hypersensitivity, Immediate / Q000453:epidemiology / Q000209:etiology* / Q000276:immunology; D007107:Immune System / Q000502:physiology; D007223:Infant; D007239:Infections / Q000150:complications* / Q000276:immunology; D006255:Rhinitis, Allergic, Seasonal / Q000209:etiology* / Q000276:immunology; D035781:Siblings