title: The epidemiology of polyparasitism and implications for morbidity in two rural communities of Côte d'Ivoire.
abstract: BACKGROUND
  Polyparasitism is still widespread in rural communities of the developing world. However, the epidemiology of polyparasitism and implications for morbidity are poorly understood. We studied patterns of multiple species parasite infection in two rural communities of Côte d'Ivoire, including associations and interactions between infection, clinical indicators and self-reported morbidity.
  
  
  METHODS
  Between August and September 2011, two purposely selected rural communities in southern Côte d'Ivoire were screened for helminth, intestinal protozoa and Plasmodium infection, using a suite of quality-controlled diagnostic methods. Additionally, participants were examined clinically and we measured haemoglobin level, height, weight and mid-upper arm circumference to determine nutritional status. An anamnestic questionnaire was administered to assess people's recent history of diseases and symptoms, while a household questionnaire was administered to heads of household to collect socioeconomic data. Multivariate logistic regression models were applied for assessment of possible associations between parasitic (co-)infections and morbidity outcomes.
  
  
  RESULTS
  912/1,095 (83.3%) study participants had complete parasitological data and 852 individuals were considered for in-depth analysis. The rate of polyparasitism was high, with Plasmodium falciparum diagnosed as the predominant species, followed by Schistosoma haematobium, Schistosoma mansoni and hookworm. There were considerable differences in polyparasitic infection profiles among the two settings. Clinical morbidity such as anaemia, splenomegaly and malnutrition was mainly found in young age groups, while in adults, self-reported morbidity dominated. High parasitaemia of P. falciparum was significantly associated with several clinical manifestations such as anaemia, splenomegaly and fever, while light-intensity helminth infections seemed to have beneficial effects, particularly for co-infected individuals.
  
  
  CONCLUSIONS
  Clinical morbidity is disturbingly high in young age groups in rural communities of Côte d'Ivoire and mainly related to very high P. falciparum endemicity. Interactions between helminth infections and P. falciparum burden (parasitaemia and clinical morbidity) are evident and must be taken into account to design future interventions.
authors.forename: Eveline
authors.initials: E
authors.lastname: Hürlimann
authors.forename: Richard B
authors.initials: RB
authors.lastname: Yapi
authors.forename: Clarisse A
authors.initials: CA
authors.lastname: Houngbedji
authors.forename: Thomas
authors.initials: T
authors.lastname: Schmidlin
authors.forename: Bernadette A
authors.initials: BA
authors.lastname: Kouadio
authors.forename: Kigbafori D
authors.initials: KD
authors.lastname: Silué
authors.forename: Mamadou
authors.initials: M
authors.lastname: Ouattara
authors.forename: Eliézer K
authors.initials: EK
authors.lastname: N'Goran
authors.forename: Jürg
authors.initials: J
authors.lastname: Utzinger
authors.affiliation: Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, P,O, Box, CH-4002, Basel, Switzerland. giovanna.raso@unibas.ch.
authors.forename: Giovanna
authors.initials: G
authors.lastname: Raso
mesh_terms: D000293:Adolescent; D000328:Adult; D000723:Ancylostomatoidea / Q000302:isolation & purification; D000818:Animals; D002648:Child; D002675:Child, Preschool; D060085:Coinfection; D007560:Cote d'Ivoire / Q000453:epidemiology; D005243:Feces / Q000469:parasitology; D005260:Female; D006373:Helminthiasis / Q000453:epidemiology* / Q000469:parasitology; D006376:Helminths / Q000302:isolation & purification*; D006725:Hookworm Infections / Q000453:epidemiology / Q000469:parasitology; D006801:Humans; D016015:Logistic Models; D016778:Malaria, Falciparum / Q000453:epidemiology* / Q000469:parasitology; D008297:Male; D015999:Multivariate Analysis; D010963:Plasmodium falciparum / Q000302:isolation & purification*; D012424:Rural Population; D012547:Schistosoma / Q000302:isolation & purification; D012552:Schistosomiasis / Q000453:epidemiology / Q000469:parasitology; D055815:Young Adult