title: Association between allergic responses and Schistosoma mansoni infection in residents in a low-endemic setting in Brazil.
abstract: BACKGROUND
  Schistosomiasis is endemic in 76 countries and territories. Several studies have found an inverse correlation between parasitic disease and the development of allergies. The purpose of the present study was to determine whether infection with Schistosoma mansoni in subjects with a low parasite load is protective against allergy. The final sample consisted of 39 S. mansoni-positive and 52 S. mansoni-negative residents of a small community in northeastern Brazil.
  
  
  METHODS
  All subjects were submitted to the Kato-Katz test, anti-S. mansoni IgG measurement, the prick test for aeroallergens, eosinophil counts and serum IgE measurement.
  
  
  RESULTS
  Subjects who reacted to one or more antigens in the prick test were considered allergic. Only 7 S. mansoni-positive subjects (17.9%) reacted to one or more antigens, whereas 20 S. mansoni-negative subjects (38.5%) tested positive for allergy.
  
  
  CONCLUSIONS
  Our findings suggest that, in areas of low endemicity, infection with S. mansoni significantly reduces the risk of the development of allergy in subjects with a low parasite load.
authors: Departamento de Patologia e Medicina Legal, Universidade Federal do Ceará, Fortaleza, CE, Brazil.
authors: Sara Menezes de
authors: SM
authors: Oliveira
authors: Departamento de Patologia e Medicina Legal, Universidade Federal do Ceará, Fortaleza, CE, Brazil.
authors: Fernando Schemelzer de Moraes
authors: FS
authors: Bezerra
authors: Departamento de Patologia e Medicina Legal, Universidade Federal do Ceará, Fortaleza, CE, Brazil.
authors: Teiliane Rodrigues
authors: TR
authors: Carneiro
authors: Departamento de Análises Clínicas e Toxicológicas, Universidade Federal do Ceará, Fortaleza, CE, Brazil.
authors: Marta Cristhiany Cunha
authors: MC
authors: Pinheiro
authors: Departamento de Patologia e Medicina Legal, Universidade Federal do Ceará, Fortaleza, CE, Brazil.
authors: José Ajax Nogueira
authors: JA
authors: Queiroz
mesh_terms: D000485:Allergens / Q000276:immunology*; D000818:Animals; D000909:Antibodies, Helminth / Q000097:blood*; D000947:Antigens, Helminth / Q000276:immunology*; D001938:Brazil / Q000453:epidemiology; D016022:Case-Control Studies; D005243:Feces / Q000469:parasitology; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000276:immunology*; D007073:Immunoglobulin E; D010270:Parasite Egg Count; D012550:Schistosoma mansoni / Q000276:immunology*; D012555:Schistosomiasis mansoni / Q000453:epidemiology / Q000276:immunology*; D012882:Skin Tests
chemical_list: D000485:Allergens; D000909:Antibodies, Helminth; D000947:Antigens, Helminth; D007073:Immunoglobulin E