title: Influence of Schistosoma mansoni and Hookworm Infection Intensities on Anaemia in Ugandan Villages.
abstract: BACKGROUND
  The association of anaemia with intestinal schistosomiasis and hookworm infections are poorly explored in populations that are not limited to children or pregnant women.
  
  
  METHODS
  We sampled 1,832 individuals aged 5-90 years from 30 communities in Mayuge District, Uganda. Demographic, village, and parasitological data were collected. Infection risk factors were compared in ordinal logistic regressions. Anaemia and infection intensities were analyzed in multilevel models, and population attributable fractions were estimated.
  
  
  RESULTS
  Household and village-level predictors of Schistosoma mansoni and hookworm were opposite in direction or significant for single infections. S. mansoni was found primarily in children, whereas hookworm was prevalent amongst the elderly. Anaemia was more prevalent in individuals with S. mansoni and increased by 2.86 fold (p-value<0.001) with heavy S. mansoni infection intensity. Individuals with heavy hookworm were 1.65 times (p-value = 0.008) more likely to have anaemia than uninfected participants. Amongst individuals with heavy S. mansoni infection intensity, 32.0% (p-value<0.001) of anaemia could be attributed to S. mansoni. For people with heavy hookworm infections, 23.7% (p-value = 0.002) of anaemia could be attributed to hookworm. A greater fraction of anaemia (24.9%, p-value = 0.002) was attributable to heavy hookworm infections in adults (excluding pregnant women) as opposed to heavy hookworm infections in school-aged children and pregnant women (20.2%, p-value = 0.001).
  
  
  CONCLUSIONS
  Community-based surveys captured anaemia in children and adults affected by S. mansoni and hookworm infections. For areas endemic with schistosomiasis or hookworm infections, WHO guidelines should include adults for treatment in helminth control programmes.
authors.affiliation: Department of Land Economy, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Goylette F
authors.initials: GF
authors.lastname: Chami
authors.affiliation: Schistosomiasis Control Initiative, Imperial College London, London, United Kingdom.
authors.forename: Alan
authors.initials: A
authors.lastname: Fenwick
authors.affiliation: D Department of Land Economy, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Erwin
authors.initials: E
authors.lastname: Bulte
authors.affiliation: Department of Land Economy, University of Cabridge, Cambridge, United Kingdom.
authors.forename: Andreas A
authors.initials: AA
authors.lastname: Kontoleon
authors.affiliation: Schistosomiasis Control Initiative, Imperial College London, London, United Kingdom; Uganda Ministry of Health, Vector Control Division, Bilharzia and Worm Control Programme, Kampala, Uganda.
authors.forename: Narcis B
authors.initials: NB
authors.lastname: Kabatereine
authors.affiliation: Uganda Ministry of Health, Vector Control Division, Bilharzia and Worm Control Programme, Kampala, Uganda.
authors.forename: Edridah M
authors.initials: EM
authors.lastname: Tukahebwa
authors.affiliation: Department of Pathology, University of Cambridge, Cambridge, United Kingdom.
authors.forename: David W
authors.initials: DW
authors.lastname: Dunne
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000740:Anemia / Q000453:epidemiology / Q000473:pathology*; D000818:Animals; D002648:Child; D002675:Child, Preschool; D005260:Female; D006725:Hookworm Infections / Q000150:complications* / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011247:Pregnancy; D012307:Risk Factors; D012424:Rural Population; D012555:Schistosomiasis mansoni / Q000150:complications* / Q000453:epidemiology; D014454:Uganda / Q000453:epidemiology; D055815:Young Adult