Volume 76, Issue 5
  • ISSN: 0002-9637
  • E-ISSN: 1476-1645


An important epidemiologic feature of schistosomiasis is the focal distribution of the disease. Thus, the identification of high-risk communities is an essential first step for targeting interventions in an efficient and cost-effective manner. We used a remotely-sensed digital elevation model (DEM), derived hydrologic features (i.e., stream order, and catchment area), and fitted Bayesian geostatistical models to assess associations between environmental factors and infection with among more than 4,000 school children from the region of Man in western Côte d’Ivoire. At the unit of the school, we found significant correlations between the infection prevalence of and stream order of the nearest river, water catchment area, and altitude. In conclusion, the use of a freely available 90 m high-resolution DEM, geographic information system applications, and Bayesian spatial modeling facilitates risk prediction for , and is a powerful approach for risk profiling of other neglected tropical diseases that are pervasive in the developing world.


Article metrics loading...

Loading full text...

Full text loading...



  1. World Health Organization, 2002. Prevention and control of schistosomiasis and soil-transmitted helminthiasis: report of a WHO expert committee. WHO Tech Rep Ser 912 : 1–57.
  2. King CH, Dickman K, Tisch DJ, 2005. Reassessment of the cost of chronic helmintic infection: a meta-analysis of disability-related outcomes in endemic schistosomiasis. Lancet 365 : 1561–1569.
  3. Utzinger J, Keiser J, 2004. Schistosomiasis and soil-transmitted helminthiasis: common drugs for treatment and control. Expert Opin Pharmacother 5 : 263–285.
  4. Gryseels B, Polman K, Clerinx J, Kestens L, 2006. Human schistosomiasis. Lancet 368 : 1106–1118.
  5. Steinmann P, Keiser J, Bos R, Tanner M, Utzinger J, 2006. Schistosomiasis and water resources development: systematic review, meta-analysis, and estimates of people at risk. Lancet Infect Dis 6 : 411–425.
  6. Bavia ME, Malone JB, Hale L, Dantas A, Marroni L, Reis R, 2001. Use of thermal and vegetation index data from earth observing satellites to evaluate the risk of schistosomiasis in Bahia, Brazil. Acta Trop 79 : 79–85.
  7. Fenwick A, Keiser J, Utzinger J, 2006. Epidemiology, burden and control of schistosomiasis with particular consideration to past and current treatment trends. Drugs Fut 31 : 413–425.
  8. Clennon JA, King CH, Muchiri EM, Kariuki HC, Ouma JH, Mungai P, Kitron U, 2004. Spatial patterns of urinary schistosomiasis infection in a highly endemic area of coastal Kenya. Am J Trop Med Hyg 70 : 443–448.
  9. Clements ACA, Lwambo NJS, Blair L, Nyandindi U, Kaatano G, Kinung’hi S, Webster JP, Fenwick A, Brooker S, 2006. Bayesian spatial analysis and disease mapping: tools to enhance planning and implementation of a schistosomiasis control programme in Tanzania. Trop Med Int Health 11 : 490–503.
  10. Raso G, Matthys B, N’Goran EK, Tanner M, Vounatsou P, Utzinger J, 2005. Spatial risk prediction and mapping of Schistosoma mansoni infections among schoolchildren living in western Côte d’Ivoire. Parasitology 131 : 97–108.
  11. Raso G, Vounatsou P, Gosoniu L, Tanner M, N’Goran EK, Utzinger J, 2006. Risk factors and spatial patterns of hookworm infection among schoolchildren in a rural area of western Côte d’Ivoire. Int J Parasitol 36 : 201–210.
  12. Wright R, Garbeil H, Baloga SM, Mouginis-Mark PJ, 2006. An assessment of shuttle radar topography mission digital elevation data for studies of volcano morphology. Remote Sens Environ 105 : 41–53.
  13. Rabus B, Eineder M, Roth A, Bamler R, 2003. The shuttle radar topography mission-a new class of digital elevation models acquired by spaceborne radar. ISPRS-J Photogramm Remote Sens 57 : 241–262.
  14. Doumenge JP, Mott KE, Cheung C, Villenave D, Chapuis O, Perrin MF, Read-Thomas G, 1987. Atlas of the Global Distribution of Schistosomiasis. Geneva: World Health Organization.
  15. Raso G, Utzinger J, Silué KD, Ouattara M, Yapi A, Toty A, Matthys B, Vounatsou P, Tanner M, N’Goran EK, 2005. Disparities in parasitic infections, perceived ill health and access to health care among poorer and less poor schoolchildren of rural Côte d’Ivoire. Trop Med Int Health 10 : 42–57.
  16. Strahler A, Strahler A, 2005. Physical Geography: Science and Systems of the Human Environment. New York: John Wiley & Sons.
  17. Brown DS, 1994. Freshwater Snails of Africa and Their Medical Importance. London: Taylor and Francis.
  18. Jensen SK, Domingue JO, 1988. Extracting topographic structure from digital elevation data for geographic information system analysis. Photogramm Eng Remote Sens 54 : 1593–1600.
  19. Strahler AN, 1952. Hypsometric (area-altitude) analysis of erosional topography. Geol Soc Am Bull 63 : 1117–1141.
  20. Strahler AN, 1957. Quantitative analysis of watershed geomorphology. EOS Trans Am Geophys Union 38 : 913–920.
  21. Gorokhovich Y, Voustianiouk A, 2006. Accuracy assessment of the processed SRTM-based elevation data by CGIAR using field data from USA and Thailand and its relation to the terrain characteristics. Remote Sens Environ 104 : 409–415.
  22. Ecker MD, Gelfand AE, 1997. Bayesian variogram modeling for an isotropic spatial process. J Agric Biol Environ Stat 2 : 347–369.
  23. Banerjee S, Gelfand AE, Knight JR, Sirmans CF, 2004. Spatial modeling of house prices using normalized distance-weighted sums of stationary processes. J Bus Econ Stat 22 : 206–213.
  24. Raso G, Vounatsou P, Singer BH, N’Goran EK, Tanner M, Utzinger J, 2006. An integrated approach for risk profiling and spatial prediction of Schistosoma mansoni-hookworm co-infection. Proc Natl Acad Sci USA 103 : 6934–6939.
  25. Gelfand AE, Smith AFM, 1990. Sampling-based approaches to calculating marginal densities. J Am Stat Assoc 85 : 398–409.
  26. Spiegelhalter DJ, Best NG, Carlin BP, Linde AVD, 2002. Bayesian measures of model complexity and fit. J R Stat Soc Ser B Stat Methodol 64 : 583–616.
  27. Diggle PJ, Tawn JA, Moyeed RA, 1998. Model-based geostatistics. Appl Stat 47 : 299–350.
  28. Gosoniu L, Vounatsou P, Sogoba N, Smith T, 2006. Bayesian modelling of geostatistical malaria risk data. Geospatial Health 1 : 127–139.
  29. Rytkönen MJ, 2004. Not all maps are equal: GIS and spatial analysis in epidemiology. Int J Circumpolar Health 63 : 9–24.
  30. Chatelain C, Gautier L, Spichiger R, 1996. A recent history of forest fragmentation in southwestern Ivory Coast. Biodivers Conserv 5 : 37–53.
  31. Hay SI, 2000. An overview of remote sensing and geodesy for epidemiology and public health application. Adv Parasitol 47 : 1–35.
  32. Brooker S, Michael E, 2000. The potential of geographical information systems and remote sensing in the epidemiology and control of human helminth infections. Adv Parasitol 47 : 245–288.
  33. Kabatereine NB, Brooker S, Tukahebwa EM, Kazibwe F, Onapa AW, 2004. Epidemiology and geography of Schistosoma mansoni in Uganda: implications for planning control. Trop Med Int Health 9 : 372–380.
  34. Appleton CC, 1978. Review of literature on abiotic factors influencing the distribution and life dynamics, and control. Malacol Rev 11 : 1–25.
  35. Kloos H, de Souza C, Gazzinelli A, Soares BS, Temba PD, Bethony J, Page K, Grzywacz C, Lewis F, Minchella D, LoVerde P, Oliveira RC, 2001. The distribution of Biomphalaria spp. in different habitats in relation to physical, biological, water contact and cognitive factors in a rural area in Minas Gerais, Brazil. Mem Inst Oswaldo Cruz 96 : 57–66.
  36. Shreve RL, 1966. Statistical law of stream numbers. J Geol 74 : 17–37.
  37. Beven K, Kirkby MJ, 1979. A physically based, variable contributing area model of basin hydrology. Hydrolog Sci Bull 24 : 43–69.
  38. Sørensen R, Zinko U, Seibert J, 2006. On the calculation of the topographic wetness index: evaluation of different methods based on field observations. Hydrol Earth Syst Sci 10 : 101–112.
  39. Staubach C, Thulke HH, Tackmann K, Hugh-Jones M, Conraths FJ, 2001. Geographic information system-aided analysis of factors associated with the spatial distribution of Echinococcus multilocularis infections of foxes. Am J Trop Med Hyg 65 : 943–948.

Data & Media loading...

  • Received : 07 Dec 2006
  • Accepted : 06 Feb 2007

Most Cited This Month

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error