title: Household contact with pets and birds and risk of lymphoma.
abstract: BACKGROUND
  Contact with household pets has been suggested to be inversely associated with lymphoma risk.
  
  
  METHODS
  We tested the hypothesis in a case-control study of lymphoma in the Sardinia region of Italy. Cases were 326 patients, first diagnosed with lymphoma in 1999-2003. Controls were 464 population controls, frequency matched to cases by age, gender, and area of residence. In person interviews included self-reported household contact with pets and birds, type of pet(s), and age at starting contact.
  
  
  RESULTS
  Frequent contact with birds was inversely associated with lymphoma, and particularly B-cell non-Hodgkin lymphoma (odds ratio [OR] = 0.6, 95% confidence interval [95% CI]: 0.4, 0.9). Contact with chickens accounted for this inverse association, which was strongest for first contact occurring at age ≤8 years (OR = 0.4, 95% CI: 0.2, 1.0). No association was observed when first contact occurred at age 9 or older. Contact with any pets was inversely associated with risk of diffuse large B-cell lymphoma (OR = 0.4, 95% CI: 0.2, 1.0), but not other lymphoma subtypes.
  
  
  CONCLUSIONS
  Our results support the hypothesis that early-life exposure to pets, birds and particularly with chickens might be associated with a reduced risk of lymphoma.
authors.affiliation: Department of Public Health, University of Cagliari, Policlinico Universitario, Monserrato, Italy.
authors.forename: Saverio
authors.initials: S
authors.lastname: Bellizzi
authors.forename: Pierluigi
authors.initials: P
authors.lastname: Cocco
authors.forename: Mariagrazia
authors.initials: M
authors.lastname: Zucca
authors.forename: Ileana
authors.initials: I
authors.lastname: D'Andrea
authors.forename: Simonetta
authors.initials: S
authors.lastname: Sesler
authors.forename: Maria
authors.initials: M
authors.lastname: Monne
authors.forename: Angela
authors.initials: A
authors.lastname: Onida
authors.forename: Giovanna
authors.initials: G
authors.lastname: Piras
authors.forename: Antonella
authors.initials: A
authors.lastname: Uras
authors.forename: Emanuele
authors.initials: E
authors.lastname: Angelucci
authors.forename: Attilio
authors.initials: A
authors.lastname: Gabbas
authors.forename: Marco
authors.initials: M
authors.lastname: Rais
authors.forename: Dorothea
authors.initials: D
authors.lastname: Nitsch
authors.forename: Maria G
authors.initials: MG
authors.lastname: Ennas
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D000829:Animals, Domestic; D001717:Birds; D016022:Case-Control Studies; D005191:Family Characteristics; D005260:Female; D001841:Human-Animal Bond; D006801:Humans; D008223:Lymphoma / Q000453:epidemiology / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D057805:Pets; D012307:Risk Factors