title: Reducing occurrence of Giardia duodenalis in children living in semiarid regions: impact of a large scale rainwater harvesting initiative.
abstract: BACKGROUND
  In Brazil, about two million people living in rural semiarid regions were benefited with the construction of rainwater cement cisterns, as an initiative from the program "One Million Cisterns" (P1MC). Nevertheless, few epidemiological studies have been conducted to assess health risks or protection effects associated with consumption of this water source. The aim of this study was to evaluate whether access to rainwater harvesting cisterns is associated with the decrease in the occurrence of Giardia duodenalis infections in children, compared to other children living in households supplied by other water sources.
  
  
  RESULTS
  A quasi-experimental study with two concurrent cohorts was developed in two rural municipalities of the semiarid region of Brazil. A sample of 664 children, aged between 4 months and 5 years old, was followed up, of which 332 had access to rainwater cisterns (cistern group) and 332 did not, having water supplied from alternative sources (comparison group). In a period of approximately one year (2010) intestinal parasites were investigated in feces three times. The prevalence of G. duodenalis in children from the cistern group ranged from 4.8 to 10.5%, while the prevalence in the comparison group ranged from 7.6 to 16.7%. Multivariate analysis (GEE) showed a higher risk of G. duodenalis infection in children who did not have access to rainwater cisterns, when compared to children who did (OR 1.72; 95% CI 1.14-2.59). The other variables associated with G. duodenalis infection were: number of rooms per house (OR 0.89; 95% CI 0.80-0.99); family income (OR0.48; 95% CI 0.26-0.88); birth order (OR 1.72; 95% CI 1.17-2.51); preterm children (OR 1.70; 95% CI 1.19-2.43); and improper hand hygiene prior to food preparation (OR 4.78; 95% CI 1.95-11.76).
  
  
  CONCLUSIONS
  Ownership of a rainwater cistern is associated with a lower prevalence of G. duodenalis infection in children after adjustment for environmental and family-related factors. Nevertheless, the study suggests the necessity to complement physical interventions with actions related to personal and domestic hygiene to enable further reductions in parasite infections affecting mainly the underprivileged populations.
authors.affiliation: School of Engineering; Department of Sanitary and Environmental Engineering - Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Jacqueline Evangelista
authors.initials: JE
authors.lastname: Fonseca
authors.affiliation: Department of Parasitology; Institute of Biological Sciences and Graduate Program in Health Sciences: Infectious Diseases and Tropical Medicine - Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Mariângela
authors.initials: M
authors.lastname: Carneiro
authors.affiliation: School of Engineering; Department of Sanitary and Environmental Engineering - Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: João Luiz
authors.initials: JL
authors.lastname: Pena
authors.affiliation: Department of Statistics; Institute of Mathematical Sciences - Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Enrico A
authors.initials: EA
authors.lastname: Colosimo
authors.affiliation: Department of Statistics; Institute of Mathematical Sciences - Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Nívea Bispo
authors.initials: NB
authors.lastname: da Silva
authors.affiliation: Department of Statistics; Institute of Mathematical Sciences - Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: André Gabriel F C
authors.initials: AG
authors.lastname: da Costa
authors.affiliation: Laboratory of Parasitology - Universidade Presidente Antônio Carlos, Teófilo Otoni, Minas Gerais, Brazil.
authors.forename: Luciano E
authors.initials: LE
authors.lastname: Moreira
authors.affiliation: London School of Hygiene and Tropical Medicine, London, United Kingdom.
authors.forename: Sandy
authors.initials: S
authors.lastname: Cairncross
authors.affiliation: School of Engineering; Department of Sanitary and Environmental Engineering - Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Léo
authors.initials: L
authors.lastname: Heller
mesh_terms: D001938:Brazil / Q000453:epidemiology; D002675:Child, Preschool; D060766:Drinking Water; D005243:Feces / Q000469:parasitology; D005260:Female; D016829:Giardia lamblia / Q000302:isolation & purification*; D005873:Giardiasis / Q000453:epidemiology* / Q000517:prevention & control*; D006801:Humans; D007223:Infant; D008297:Male; D065228:Non-Randomized Controlled Trials as Topic; D015995:Prevalence; D012424:Rural Population
chemical_list: D060766:Drinking Water