Influence of dog ownership and high endotoxin on wheezing and atopy during infancy.
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.
Campo
Paloma
P
Department of Internal Medicine, Immunology Division, University of Cincinnati, Cincinnati, OH 45267-0563, USA.
Kalra
Harpinder K
HK
Levin
Linda
L
Reponen
Tiina
T
Olds
Rolanda
R
Lummus
Zana L
ZL
Cho
Seung-Hyun
SH
Khurana Hershey
Gurjit K
GK
Lockey
James
J
Villareal
Manuel
M
Stanforth
Sherry
S
Lemasters
Grace
G
Bernstein
David I
DI
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
D000485:Allergens; D004391:Dust; D004731:Endotoxins