title: Influence of dog ownership and high endotoxin on wheezing and atopy during infancy.
abstract: BACKGROUND
  Increased exposure to microbial products early in life may protect from development of atopic disorders in childhood. Few studies have examined the relationship of endotoxin exposure and pet ownership on atopy and wheezing during infancy.
  
  
  OBJECTIVE
  Evaluate relationships among high endotoxin exposure, pet ownership, atopy, and wheezing in high-risk infants.
  
  
  METHODS
  Infants (n = 532; mean age, 12.5 +/- 0.8 months) with at least 1 parent with confirmed atopy were recruited. A complete medical history and skin prick testing to foods and aeroallergens were performed at age 1 year. House dust samples were analyzed for endotoxin.
  
  
  RESULTS
  Prevalences of wheezing were not independently associated with dog or cat ownership or endotoxin levels. Percutaneous reactivity to at least 1 allergen was observed in 28.6% of infants. Univariate analyses showed significant associations of any wheezing, recurrent wheezing, and recurrent wheezing with an event with daycare attendance, number of siblings, respiratory infections, maternal smoking, and history of parental asthma. Logistic regression adjusting for the latter variables showed that recurrent wheezing (odds ratio, 0.4; 95% CI, 0.1-0.9) as well as 2 other wheeze outcomes were significantly reduced in homes with high endotoxin exposure in the presence of 2 or more dogs.
  
  
  CONCLUSIONS
  Pet ownership or endotoxin did not independently modify aeroallergen sensitization or wheezing during infancy. However, high endotoxin exposure in the presence of multiple dogs was associated with reduced wheezing in infants.
  
  
  CONCLUSIONS
  A home environment with many dogs and high levels of endotoxin may be conducive to reduced wheezing in infancy.
authors.affiliation: Department of Internal Medicine, Immunology Division, University of Cincinnati, Cincinnati, OH 45267-0563, USA.
authors.forename: Paloma
authors.initials: P
authors.lastname: Campo
authors.forename: Harpinder K
authors.initials: HK
authors.lastname: Kalra
authors.forename: Linda
authors.initials: L
authors.lastname: Levin
authors.forename: Tiina
authors.initials: T
authors.lastname: Reponen
authors.forename: Rolanda
authors.initials: R
authors.lastname: Olds
authors.forename: Zana L
authors.initials: ZL
authors.lastname: Lummus
authors.forename: Seung-Hyun
authors.initials: SH
authors.lastname: Cho
authors.forename: Gurjit K
authors.initials: GK
authors.lastname: Khurana Hershey
authors.forename: James
authors.initials: J
authors.lastname: Lockey
authors.forename: Manuel
authors.initials: M
authors.lastname: Villareal
authors.forename: Sherry
authors.initials: S
authors.lastname: Stanforth
authors.forename: Grace
authors.initials: G
authors.lastname: Lemasters
authors.forename: David I
authors.initials: DI
authors.lastname: Bernstein
mesh_terms: D000485:Allergens / Q000032:analysis*; D000818:Animals; D015331:Cohort Studies; D004285:Dogs; D004391:Dust / Q000032:analysis*; D004731:Endotoxins / Q000032:analysis*; D004781:Environmental Exposure / Q000032:analysis*; D005260:Female; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000453:epidemiology*; D007223:Infant; D008297:Male; D009820:Ohio / Q000453:epidemiology; D015995:Prevalence; D011446:Prospective Studies; D012135:Respiratory Sounds; D012307:Risk Factors; D011795:Surveys and Questionnaires
chemical_list: D000485:Allergens; D004391:Dust; D004731:Endotoxins