title: An updated atlas of human helminth infections: the example of East Africa.
abstract: BACKGROUND
  Reliable and updated maps of helminth (worm) infection distributions are essential to target control strategies to those populations in greatest need. Although many surveys have been conducted in endemic countries, the data are rarely available in a form that is accessible to policy makers and the managers of public health programmes. This is especially true in sub-Saharan Africa, where empirical data are seldom in the public domain. In an attempt to address the paucity of geographical information on helminth risk, this article describes the development of an updated global atlas of human helminth infection, showing the example of East Africa.
  
  
  METHODS
  Empirical, cross-sectional estimates of infection prevalence conducted since 1980 were identified using electronic and manual search strategies of published and unpublished sources. A number of inclusion criteria were imposed for identified information, which was extracted into a standardized database. Details of survey population, diagnostic methods, sample size and numbers infected with schistosomes and soil-transmitted helminths were recorded. A unique identifier linked each record to an electronic copy of the source document, in portable document format. An attempt was made to identify the geographical location of each record using standardized geolocation procedures and the assembled data were incorporated into a geographical information system.
  
  
  RESULTS
  At the time of writing, over 2,748 prevalence surveys were identified through multiple search strategies. Of these, 2,612 were able to be geolocated and mapped. More than half (58%) of included surveys were from grey literature or unpublished sources, underlining the importance of reviewing in-country sources. 66% of all surveys were conducted since 2000. Comprehensive, countrywide data are available for Burundi, Rwanda and Uganda. In contrast, information for Kenya and Tanzania is typically clustered in specific regions of the country, with few records from areas with very low population density and/or environmental conditions which are unfavourable for helminth transmission. Information is presented on the prevalence and geographical distribution for the major helminth species.
  
  
  CONCLUSIONS
  For all five countries, the information assembled in the current atlas provides the most reliable, up-to-date and comprehensive source of data on the distribution of common helminth infections to guide the rational implementation of control efforts.
authors: Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, UK. simon.brooker@lshtm.ac.uk
authors: Simon
authors: S
authors: Brooker
authors: Narcis B
authors: NB
authors: Kabatereine
authors: Jennifer L
authors: JL
authors: Smith
authors: Denise
authors: D
authors: Mupfasoni
authors: Mariam T
authors: MT
authors: Mwanje
authors: Onésime
authors: O
authors: Ndayishimiye
authors: Nicholas Js
authors: NJ
authors: Lwambo
authors: Deborah
authors: D
authors: Mbotha
authors: Peris
authors: P
authors: Karanja
authors: Charles
authors: C
authors: Mwandawiro
authors: Eric
authors: E
authors: Muchiri
authors: Archie Ca
authors: AC
authors: Clements
authors: Donald Ap
authors: DA
authors: Bundy
authors: Robert W
authors: RW
authors: Snow
mesh_terms: D017954:Africa South of the Sahara / Q000453:epidemiology; D000818:Animals; D001271:Atlases as Topic; D003430:Cross-Sectional Studies; D003710:Demography; D006373:Helminthiasis / Q000453:epidemiology*; D006376:Helminths; D006801:Humans; D015995:Prevalence; D012547:Schistosoma