Study of risk factors for atopic sensitization, asthma, and bronchial hyperresponsiveness in animal laboratory workers.
OBJECTIVE
The aim of this estudy was to investigate the influence of allergen exposure levels and other risk factors for allergic sensitization, asthma, and bronchial hyperresponsiveness (BHR) in workers exposed to laboratory animals.


METHODS
This was a cross-sectional study performed at two universities, 123 workplaces with 737 subjects. Dust samples were collected from laboratories and animal facilities housing rats, mice, guinea pigs, rabbits, or hamsters and analyzed by enzyme-linked immunosorbent assay (ELISA) to measure allergen concentrations. We also sampled workplaces without animals. Asthma was defined by both symptoms and BHR to mannitol. The concentrations of allergens were tested for association with a skin prick test, respiratory symptoms, spirometry data, and BHR. This multivariate analysis was performed by using Poisson regression to estimate the relative risk (RR) for the exposed group.


RESULTS
Our sample comprised students and workers, with 336 subjects in the nonexposed group and 401 subjects in the exposed group. Sixty-nine subjects (17%) had positive results in the skin prick test for animal allergens in the exposed group; in the nonexposed group, 10 subjects had positive results (3%) (p<0.001). Exposure to laboratory animals over 2.8 years was associated with atopic sensitization (RR=1.85; 95% confidence interval: 1.09-3.15; p=0.02). Allergen concentration was not associated with sensitization, asthma, or BHR.


CONCLUSIONS
Exposure to laboratory animals was associated with atopic sensitization. However, we did not find a cutoff allergen concentration that increased the risk for sensitization. Duration of exposure seems to be more relevant to sensitization than concentration of allergens in dust.
Department of Medicine, Medical School of Ribeirão Preto, University of São Paulo.
Christian Silva
CS
Simoneti
Amanda Souza
AS
Freitas
Michelle Christiane Rodrigues
MC
Barbosa
Erica
E
Ferraz
Marcelo Bezerra
MB
de Menezes
Ericson
E
Bagatin
Luisa Karla
LK
Arruda
Elcio Oliveira
EO
Vianna
D000328:Adult; D000485:Allergens / Q000009:adverse effects / Q000032:analysis*; D000818:Animals; D000830:Animals, Laboratory; D059366:Asthma, Occupational / Q000209:etiology; D001938:Brazil; D016535:Bronchial Hyperreactivity / Q000209:etiology; D006224:Cricetinae; D003430:Cross-Sectional Studies; D017449:Dermatitis, Allergic Contact / Q000209:etiology; D004391:Dust / Q000032:analysis*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006168:Guinea Pigs; D006799:Housing, Animal; D006801:Humans; D006967:Hypersensitivity / Q000209:etiology*; D059232:Laboratory Personnel; D008297:Male; D051379:Mice; D009784:Occupational Diseases / Q000209:etiology*; D016273:Occupational Exposure / Q000009:adverse effects / Q000032:analysis*; D016012:Poisson Distribution; D011817:Rabbits; D051381:Rats; D012307:Risk Factors; D012882:Skin Tests; D013147:Spirometry
D000485:Allergens; D004391:Dust