title: The prevalence of parasite infestation and house dust mite sensitization in Gabonese schoolchildren.
abstract: BACKGROUND
  Allergic diseases seem less prevalent in communities in less developed parts of the world, where parasite infections are highly prevalent. Altogether not much is known about the association between chronic infections with tissue and blood-dwelling parasites and atopy.
  
  
  METHODS
  In an area in Gabon endemic for blood and tissue parasites, 520 schoolchildren were parasitologically examined and skin prick-tested for a set of common environmental aeroallergens. Levels of allergen-specific IgE and polyclonal IgE were measured.
  
  
  RESULTS
  In schoolchildren schistosome and filarial infections increased with age, whereas malaria was more prevalent in younger children. In contrast to allergen sensitization that increased with age, skin test reactivity tended to decline. The number of children with mite-specific IgE antibodies (47%) by far exceeded the number responding to skin prick testing (11%). Mite sensitization was found to be the highest in children infected with schistosomes and/or filariae whereas skin test reactivity was lowest. The multiple logistic regression showed that the risk of a positive skin test was 8-fold higher with increasing levels of mite-specific IgE but was reduced by 72% when infected with blood stage helminths.
  
  
  CONCLUSIONS
  Chronic blood and tissue parasite infections that are often capable of modulating immune responses in the host are negatively associated with skin test reactivity in a sensitized population.
authors.affiliation: Department of Parasitology, Leiden University Medical Center, NL-2300 RC Leiden, The Netherlands.
authors.forename: A H
authors.initials: AH
authors.lastname: van den Biggelaar
authors.forename: C
authors.initials: C
authors.lastname: Lopuhaa
authors.forename: R
authors.initials: R
authors.lastname: van Ree
authors.forename: J S
authors.initials: JS
authors.lastname: van der Zee
authors.forename: J
authors.initials: J
authors.lastname: Jans
authors.forename: A
authors.initials: A
authors.lastname: Hoek
authors.forename: B
authors.initials: B
authors.lastname: Migombet
authors.forename: S
authors.initials: S
authors.lastname: Borrmann
authors.forename: D
authors.initials: D
authors.lastname: Luckner
authors.forename: P G
authors.initials: PG
authors.lastname: Kremsner
authors.forename: M
authors.initials: M
authors.lastname: Yazdanbakhsh
mesh_terms: D000293:Adolescent; D000485:Allergens / Q000276:immunology*; D000818:Animals; D002648:Child; D002675:Child, Preschool; D004391:Dust; D005260:Female; D005681:Gabon / Q000453:epidemiology; D006801:Humans; D006967:Hypersensitivity / Q000150:complications / Q000453:epidemiology / Q000276:immunology*; D007073:Immunoglobulin E / Q000276:immunology; D016778:Malaria, Falciparum / Q000150:complications / Q000453:epidemiology / Q000276:immunology*; D008297:Male; D008368:Mansonelliasis / Q000150:complications / Q000453:epidemiology / Q000276:immunology*; D008925:Mites; D015995:Prevalence; D012552:Schistosomiasis / Q000150:complications / Q000453:epidemiology / Q000276:immunology*; D012882:Skin Tests
chemical_list: D000485:Allergens; D004391:Dust; D007073:Immunoglobulin E