title: Distribution and risk factors for Plasmodium and helminth co-infections: a cross-sectional survey among children in Bagamoyo district, coastal region of Tanzania.
abstract: BACKGROUND
  Plasmodium and soil transmitted helminth infections (STH) are a major public health problem, particularly among children. There are conflicting findings on potential association between these two parasites. This study investigated the Plasmodium and helminth co-infections among children aged 2 months to 9 years living in Bagamoyo district, coastal region of Tanzania.
  
  
  METHODS
  A community-based cross-sectional survey was conducted among 1033 children. Stool, urine and blood samples were examined using a broad set of quality controlled diagnostic methods for common STH (Ascaris lumbricoides, hookworm, Strongyloides stercoralis, Enterobius vermicularis, Trichuris trichura), schistosoma species and Wuchereria bancrofti. Blood slides and malaria rapid diagnostic tests (mRDTs) were utilized for Plasmodium diagnosis.
  
  
  RESULTS
  Out of 992 children analyzed, the prevalence of Plasmodium infection was 13% (130/992), helminth 28.5% (283/992); 5% (50/992) had co-infection with Plasmodium and helminth. The prevalence rate of Plasmodium, specific STH and co-infections increased significantly with age (p < 0.001), with older children mostly affected except for S. stercoralis monoinfection and co-infections. Spatial variations of co-infection prevalence were observed between and within villages. There was a trend for STH infections to be associated with Plasmodium infection [OR adjusted for age group 1.4, 95% CI (1.0-2.1)], which was more marked for S. stercoralis (OR = 2.2, 95% CI (1.1-4.3). Age and not schooling were risk factors for Plasmodium and STH co-infection.
  
  
  CONCLUSIONS
  The findings suggest that STH and Plasmodium infections tend to occur in the same children, with increasing prevalence of co-infection with age. This calls for an integrated approach such as using mass chemotherapy with dual effect (e.g., ivermectin) coupled with improved housing, sanitation and hygiene for the control of both parasitic infections.
authors.affiliation: Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, United Republic of Tanzania; Department of Pediatrics and Child Health, Muhimbili University Health and Allied Sciences (MUHAS), Dar es Salaam, United Republic of Tanzania; Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland.
authors.forename: Nahya
authors.initials: N
authors.lastname: Salim
authors.affiliation: Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland; Department of Life Sciences, Wolfson Wellcome Biomedical Laboratories, Natural History Museum, London, United Kingdom.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Knopp
authors.affiliation: Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, United Republic of Tanzania.
authors.forename: Omar
authors.initials: O
authors.lastname: Lweno
authors.affiliation: Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, United Republic of Tanzania.
authors.forename: Ummi
authors.initials: U
authors.lastname: Abdul
authors.affiliation: Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, United Republic of Tanzania.
authors.forename: Ali
authors.initials: A
authors.lastname: Mohamed
authors.affiliation: Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, United Republic of Tanzania; University of Basel, Basel, Switzerland; Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland.
authors.forename: Tobias
authors.initials: T
authors.lastname: Schindler
authors.affiliation: Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, United Republic of Tanzania; University of Basel, Basel, Switzerland; Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland.
authors.forename: Julian
authors.initials: J
authors.lastname: Rothen
authors.affiliation: Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, United Republic of Tanzania.
authors.forename: John
authors.initials: J
authors.lastname: Masimba
authors.affiliation: Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, United Republic of Tanzania.
authors.forename: Denis
authors.initials: D
authors.lastname: Kwaba
authors.affiliation: Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, United Republic of Tanzania.
authors.forename: Alisa S
authors.initials: AS
authors.lastname: Mohammed
authors.affiliation: Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland.
authors.forename: Fabrice
authors.initials: F
authors.lastname: Althaus
authors.affiliation: Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, United Republic of Tanzania.
authors.forename: Salim
authors.initials: S
authors.lastname: Abdulla
authors.affiliation: Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland.
authors.forename: Marcel
authors.initials: M
authors.lastname: Tanner
authors.affiliation: University of Basel, Basel, Switzerland; Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland.
authors.forename: Claudia
authors.initials: C
authors.lastname: Daubenberger
authors.affiliation: Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland; Department of Ambulatory Care and Community Medicine, Infectious Disease Service, Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: Blaise
authors.initials: B
authors.lastname: Genton
mesh_terms: D000818:Animals; D001769:Blood / Q000469:parasitology; D002648:Child; D002675:Child, Preschool; D060085:Coinfection / Q000453:epidemiology*; D003430:Cross-Sectional Studies; D005243:Feces / Q000469:parasitology; D006373:Helminthiasis / Q000175:diagnosis* / Q000453:epidemiology*; D006376:Helminths / Q000302:isolation & purification; D006801:Humans; D007223:Infant; D008288:Malaria / Q000175:diagnosis* / Q000453:epidemiology*; D010961:Plasmodium / Q000302:isolation & purification; D015995:Prevalence; D012307:Risk Factors; D012987:Soil / Q000469:parasitology; D011795:Surveys and Questionnaires; D013636:Tanzania / Q000453:epidemiology; D014556:Urine / Q000469:parasitology
chemical_list: D012987:Soil
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