title: Heterogeneities and consequences of Plasmodium species and hookworm coinfection: a population based study in Uganda.
abstract: BACKGROUND
  Previous studies have suggested that helminth infection exacerbates malaria, but few existing epidemiological studies adequately control for infection heterogeneities and confounding factors. In this study, we investigate spatial and household heterogeneities, predictors, and consequences of Plasmodium species and hookworm coinfection in rural communities in Uganda.
  
  
  METHODS
  A cross-sectional study was conducted among 1770 individuals aged 0-88 years in 4 villages. We recorded demographic, socioeconomic, and microgeographic factors during household surveys. We determined malaria parasitemia and hemoglobin concentration and collected stool samples on 2 consecutive days. For data analysis, we used a hierarchical, spatially explicit Bayesian framework.
  
  
  RESULTS
  Prevalence of Plasmodium-hookworm coinfection was 15.5% overall and highest among school-aged children. We found strong evidence of spatial and household clustering of coinfection and an enduring positive association between Plasmodium-species and hookworm infection among preschool-aged children (odds ratio [OR], 2.36; 95% Bayesian credible interval [BCI], 1.26-4.30) and adults (OR, 2.09; 95% BCI, 1.35-3.16) but not among school-aged children. Coinfection was associated with lower hemoglobin level only among school-aged children.
  
  
  CONCLUSIONS
  Plasmodium-hookworm coinfection exhibits marked age dependency and significant spatial and household heterogeneity, and among preschool-aged children and adults, occurs more than would be expected by chance. Such heterogeneities provide insight into factors underlying observed patterns and the design of integrated control strategies.
authors.affiliation: Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom. rachel.pullan@lshtm.ac.uk
authors.forename: Rachel L
authors.initials: RL
authors.lastname: Pullan
authors.forename: Narcis B
authors.initials: NB
authors.lastname: Kabatereine
authors.forename: Hasifa
authors.initials: H
authors.lastname: Bukirwa
authors.forename: Sarah G
authors.initials: SG
authors.lastname: Staedke
authors.forename: Simon
authors.initials: S
authors.lastname: Brooker
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006725:Hookworm Infections / Q000150:complications* / Q000453:epidemiology; D006801:Humans; D007223:Infant; D008288:Malaria / Q000150:complications* / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010961:Plasmodium; D015995:Prevalence; D012307:Risk Factors; D014454:Uganda / Q000453:epidemiology; D055815:Young Adult