title: Relationship between the presence of newborn and the house dust endotoxin.
abstract: BACKGROUND
  Exposure to house dust endotoxin induces of airways' inflammation. Endotoxin are produced by the Gram-negative bacteria, which are released into the stools and could contaminate domestic environment.
  
  
  OBJECTIVE
  The newborn could contaminate his mattress by endotoxin.
  
  
  METHODS
  The dusts of mattress and carpets of 97 newborn' dwellings were sampled at birth and after six months of life. Samplings were made in the bedroom from the baby and in the second place where the baby spent the longer time. The endotoxin concentration was measured by a quantitative Limulus assay and the bacterial contamination was evaluated using 3 selective agar media.
  
  
  RESULTS
  Endotoxin concentration at birth was positively associated with the presence of both sibling and the number of inhabitants (p<0.01). At 6 months of life, the endotoxin concentration raised significantly not only in the mattresses (from a median of 17.6 (ranges: 0.4-346.7) to 79.6 (3.8-518.8) EU/mg) (p<0.0001), but also in the dust from the second place where the baby is sleeping (from 20.4 (0.8-226.3) to 101.8 (6.5-634.3) EU/mg) (p<0.001). Importantly, there was no change in endotoxin concentration from the carpets dust, and the environmental dwelling characteristics remained unchanged. The total bacterial contamination was also positively associated with endotoxin concentration in newborn mattress at birth (p<0.01) and showed a significant increase at 6 months of life of the newborn (p<0.01).
  
  
  CONCLUSIONS
  The newborn is a significant source of house dust's endotoxin.
authors.affiliation: Clinic of Immuno-allergology, CHU Brugmann, Université Libre de Bruxelles (ULB), and Neonatal Intensive Care Unit, Hôpital Universitaire Des Enfants Reine Fabiola, HUDERF, ULB, Brussels, Belgium.
authors.forename: Virginie
authors.initials: V
authors.lastname: Doyen
authors.forename: Anne-Britt
authors.initials: AB
authors.lastname: Johansson
authors.forename: Laurence
authors.initials: L
authors.lastname: Hanssens
authors.forename: Nathalie
authors.initials: N
authors.lastname: Dehennin
authors.forename: Duc Huy Phong
authors.initials: DH
authors.lastname: Dinh
authors.forename: Georges
authors.initials: G
authors.lastname: Casimir
authors.forename: Olivier
authors.initials: O
authors.lastname: Michel
mesh_terms: D000391:Air Microbiology; D016902:Air Pollution, Indoor / Q000032:analysis*; D001513:Beds / Q000382:microbiology; D001530:Belgium; D015169:Colony Count, Microbial; D004391:Dust / Q000032:analysis*; D004731:Endotoxins / Q000032:analysis*; D004784:Environmental Monitoring; D005260:Female; D005430:Floors and Floorcoverings; D006090:Gram-Negative Bacteria / Q000737:chemistry / Q000302:isolation & purification*; D006094:Gram-Positive Bacteria / Q000302:isolation & purification; D006798:Housing; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008033:Limulus Test; D008297:Male
chemical_list: D004391:Dust; D004731:Endotoxins