title: Use of Bayesian geostatistical prediction to estimate local variations in Schistosoma haematobium infection in western Africa.
abstract: OBJECTIVE
  To predict the subnational spatial variation in the number of people infected with Schistosoma haematobium in Burkina Faso, Mali and the Niger prior to national control programmes.
  
  
  METHODS
  We used field survey data sets covering a contiguous area 2750 x 850 km and including 26,790 school-age children (5-14 years old) in 418 schools. The prevalence of high- and low-intensity infection and associated 95% credible intervals (CrIs) were predicted using Bayesian geostatistical models. The number infected was determined from the predicted prevalence and the number of school-age children in each km(2).
  
  
  RESULTS
  The predicted number of school-age children with a low-intensity infection was 433,268 in Burkina Faso, 872,328 in Mali and 580 286 in the Niger. The number with a high-intensity infection was 416,009, 511,845 and 254,150 in each country, respectively. The 95% CrIs were wide: e.g. the mean number of boys aged 10-14 years infected in Mali was 140,200 (95% CrI: 6200-512,100).
  
  
  CONCLUSIONS
  National aggregate estimates of infection mask important local variations:: e.g. most S. haematobium infections in the Niger occur in the Niger River valley. High-intensity infection was strongly clustered in western and central Mali, north-eastern and northwestern Burkina Faso and the Niger River valley in the Niger. Populations in these foci will carry the bulk of the urinary schistosomiasis burden and should be prioritized for schistosomiasis control. Uncertainties in the predicted prevalence and the numbers infected should be acknowledged by control programme planners.
authors.affiliation: University of Queensland, School of Population Health, Herston Road, Herston, Qld, 4006, Australia. a.clements@uq.edu.au
authors.forename: Archie C A
authors.initials: AC
authors.lastname: Clements
authors.forename: Sonja
authors.initials: S
authors.lastname: Firth
authors.forename: Robert
authors.initials: R
authors.lastname: Dembelé
authors.forename: Amadou
authors.initials: A
authors.lastname: Garba
authors.forename: Seydou
authors.initials: S
authors.lastname: Touré
authors.forename: Moussa
authors.initials: M
authors.lastname: Sacko
authors.forename: Aly
authors.initials: A
authors.lastname: Landouré
authors.forename: Elisa
authors.initials: E
authors.lastname: Bosqué-Oliva
authors.forename: Adrian G
authors.initials: AG
authors.lastname: Barnett
authors.forename: Simon
authors.initials: S
authors.lastname: Brooker
authors.forename: Alan
authors.initials: A
authors.lastname: Fenwick
mesh_terms: D000293:Adolescent; D000354:Africa, Western / Q000453:epidemiology; D000818:Animals; D001499:Bayes Theorem; D002648:Child; D005260:Female; D005544:Forecasting; D006306:Health Surveys; D006801:Humans; D008297:Male; D015995:Prevalence; D012548:Schistosoma haematobium; D012553:Schistosomiasis haematobia / Q000453:epidemiology*; D017062:Small-Area Analysis
references.citation: Adv Parasitol. 2006;62:221-61
references.pmid: 16647972
references.citation: Parasitology. 2001;123 Suppl:S245-60
references.pmid: 11769287
references.citation: Int J Parasitol. 2006 Feb;36(2):201-10
references.pmid: 16259987
references.citation: Am J Epidemiol. 2004 Jan 1;159(1):64-72
references.pmid: 14693661
references.citation: Kidney Int. 1997 Aug;52(2):478-81
references.pmid: 9264005
references.citation: Biostatistics. 2000 Dec;1(4):453-63
references.pmid: 12933567
references.citation: Parasitology. 1994 Jul;109 ( Pt 1):45-55
references.pmid: 8058368
references.citation: Lancet Infect Dis. 2006 Jul;6(7):411-25
references.pmid: 16790382
references.citation: Parasitol Today. 1998 Oct;14(10):435
references.pmid: 17040837
references.citation: Am J Trop Med Hyg. 1979 Sep;28(5):864-70
references.pmid: 484768
references.citation: Int J Parasitol. 2006 Sep;36(10-11):1143-51
references.pmid: 16814294
references.citation: Trans R Soc Trop Med Hyg. 1992 Jul-Aug;86(4):406-9
references.pmid: 1440818
references.citation: Proc Natl Acad Sci U S A. 2006 May 2;103(18):6934-9
references.pmid: 16632601
references.citation: Lancet Infect Dis. 2004 Jun;4(6):327-36
references.pmid: 15172341
references.citation: Filaria J. 2003 Sep 14;2(1):14
references.pmid: 14525619
references.citation: Adv Parasitol. 2006;62:119-56
references.pmid: 16647969
references.citation: Parasitology. 2006 Dec;133(Pt 6):711-9
references.pmid: 16953953
references.citation: Parasitol Today. 1998 Jan;14(1):23-6
references.pmid: 17040685
references.citation: Trends Parasitol. 2006 Aug;22(8):353-8
references.pmid: 16798089
references.citation: Parasitology. 2005 Jul;131(Pt 1):97-108
references.pmid: 16038401
references.citation: Trop Med Int Health. 2006 Apr;11(4):490-503
references.pmid: 16553932
references.citation: Bull World Health Organ. 2000;78(12):1456-65
references.pmid: 11196498
references.citation: Trop Med Int Health. 2006 Jul;11(7):1032-46
references.pmid: 16827704
references.citation: Trends Parasitol. 2006 Jul;22(7):322-6
references.pmid: 16690357