title: Effect of albendazole treatments on the prevalence of atopy in children living in communities endemic for geohelminth parasites: a cluster-randomised trial.
abstract: BACKGROUND
  Epidemiological studies have shown inverse associations between geohelminth (intestinal helminth) infection and atopy, leading to the suggestion that geohelminths might protect against allergy. Periodic deworming of school children with anthelmintics is a widely implemented intervention and has raised concerns that such programmes could increase allergy. We investigated the effect of repeated anthelmintic treatments with albendazole over 12 months on the prevalence of atopy and clinical indices of allergy.
  
  
  METHODS
  We did a cluster-randomised controlled trial in schoolchildren from 68 rural schools. Children were randomly assigned by school to either albendazole (34 schools, 1164 children) every 2 months for 12 months, or to no intervention (34 schools, 1209 children). The intervention schools received a total of seven albendazole treatments. The primary outcome was atopy at 12 months (allergen skin-test reactivity), and analysis was by intention-to-treat for whole-school analyses and per protocol for children. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN61195515.
  
  
  RESULTS
  Data for analysis were available for all schools and from 67.4% (784 of 1164) and 70.1% (848 of 1209) of children in albendazole and no-treatment groups, respectively. Albendazole treatment caused large reductions in geohelminth prevalence over the study period (adjusted odds ratio 0.13, 95% CI 0.09-0.19, p<0.001), but there was no evidence that treatment was associated with an increase in atopy prevalence (0.97, 0.68-1.39, p=0.862), or clinical allergy (wheeze, 1.07, 0.54-2.11, p=0.848) in the albendazole compared with the no-treatment group.
  
  
  CONCLUSIONS
  We saw no increase in the prevalence of atopy or clinical allergy associated with albendazole treatment. Deworming programmes for schoolchildren are unlikely to be accompanied by an increase in allergy.
authors.affiliation: Laboratorio de Investigaciones, Hospital Pedro Vicente Maldonado, Pichincha Province, Ecuador. pcooper@ecnet.ec
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Cooper
authors.forename: Martha E
authors.initials: ME
authors.lastname: Chico
authors.forename: Maritza G
authors.initials: MG
authors.lastname: Vaca
authors.forename: Ana-Lucia
authors.initials: AL
authors.lastname: Moncayo
authors.forename: J Martin
authors.initials: JM
authors.lastname: Bland
authors.forename: Evelin
authors.initials: E
authors.lastname: Mafla
authors.forename: Fernanda
authors.initials: F
authors.lastname: Sanchez
authors.forename: Laura C
authors.initials: LC
authors.lastname: Rodrigues
authors.forename: David P
authors.initials: DP
authors.lastname: Strachan
authors.forename: George E
authors.initials: GE
authors.lastname: Griffin
mesh_terms: D015766:Albendazole / Q000627:therapeutic use*; D000871:Anthelmintics / Q000627:therapeutic use*; D002648:Child; D004484:Ecuador; D005260:Female; D006373:Helminthiasis / Q000188:drug therapy*; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000276:immunology*; D008297:Male
chemical_list: D000871:Anthelmintics; D015766:Albendazole