title: Patterns of infection and day care utilization and risk of childhood acute lymphoblastic leukaemia.
abstract: To investigate if decreased exposure to common childhood infections is associated with risk of childhood acute lymphoblastic leukaemia (ALL) we conducted a case-control study of 1842 newly diagnosed and immunophenotypically defined cases of ALL under age 15, and 1986 matched controls in the US. Data regarding day care, sibship size and common childhood infections were obtained through parental interviews. Data were analysed stratified by leukaemia lineage and separately for 'common' childhood ALL (age 2-5 years, CD19, CD10-positive). Neither attendance at day care nor time at day care was associated with risk of ALL overall or 'common' ALL. Ear infections during infancy were less common among cases, with odds ratios of 0.86, 0.83, 0.71 and 0.69 for 1, 2-4, 5+ episodes, and continuous infections respectively (trend P = 0.026). No effect of sibship size or birth interval was seen. With one exception (ear infections), these data do not support the hypothesis that a decrease in the occurrence of common childhood infection increases risk of ALL.
authors.affiliation: Department of Pediatrics, University of Minnesota School of Medicine, Minneapolis, USA.
authors.forename: J P
authors.initials: JP
authors.lastname: Neglia
authors.forename: M S
authors.initials: MS
authors.lastname: Linet
authors.forename: X O
authors.initials: XO
authors.lastname: Shu
authors.forename: R K
authors.initials: RK
authors.lastname: Severson
authors.forename: J D
authors.initials: JD
authors.lastname: Potter
authors.forename: A C
authors.initials: AC
authors.lastname: Mertens
authors.forename: W
authors.initials: W
authors.lastname: Wen
authors.forename: J H
authors.initials: JH
authors.lastname: Kersey
authors.forename: L L
authors.initials: LL
authors.lastname: Robison
mesh_terms: D000293:Adolescent; D001721:Birth Intervals; D016022:Case-Control Studies; D002648:Child; D002656:Child Day Care Centers / Q000706:statistics & numerical data*; D002675:Child, Preschool; D003710:Demography; D005191:Family Characteristics; D005260:Female; D006801:Humans; D016130:Immunophenotyping; D007223:Infant; D007231:Infant, Newborn; D007239:Infections / Q000150:complications / Q000453:epidemiology*; D015448:Leukemia, B-Cell / Q000453:epidemiology* / Q000209:etiology; D015458:Leukemia, T-Cell / Q000453:epidemiology* / Q000209:etiology; D008297:Male; D016017:Odds Ratio; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000453:epidemiology* / Q000209:etiology