title: Malaria indicator surveys demonstrate a markedly lower prevalence of malaria in large cities of sub-Saharan Africa.
abstract: BACKGROUND
  One in eight sub-Saharan Africans now lives in a city with a population greater than 750,000. Decision makers require additional evidence regarding the burden of malaria in these large cities. This paper presents results from analysis of existing data from nationwide household surveys measuring malaria parasitaemia by microscopy among children six to 59 months of age in 15 countries of sub-Saharan Africa.
  
  
  METHODS
  Geo-coordinates for each survey cluster were used to determine the distance from the cluster to the centre of each of 16 large cities with populations greater than 750,000. Geo-coordinates of each site within 25 km of the centre were entered into Google Earth to obtain a satellite image of the location and determine whether it was within the boundaries of the metropolis. In the case of two countries for which survey geo-coordinates were not available, clusters located in an additional four large cities were identified based upon their designated district. Data from all sites within city boundaries were pooled together and compared to data from all rural sites within 150 km of the city centre or in the same zone of malaria endemicity.
  
  
  RESULTS
  Of the 20 large cities, only in Ouagadougou were more than 10% of children found to have a malaria infection. The prevalence was less than 5% for 16 of these cities. Apart from Antananarivo where both the large city and the comparison rural communities were parasite-free, the prevalence in each of the large cities was 0 to 40% of that found among children living in rural communities within 150 km of these cities or within the same zone of malaria endemicity. In 14 of the 20 large cities, all of the children living in 75% or more of the clusters were malaria parasite-free.
  
  
  CONCLUSIONS
  Existing data from malaria indicator surveys can be used to document the substantially lower prevalence of malaria in specific large cities. These findings will help policy makers, public health programmers and clinical workers in each country to develop and promote malaria control strategies that are suited to large cities as well as to those living in smaller communities.
authors.affiliation: Independent Consultant, Portland, Oregon, USA. pondb@mac.com.
authors.forename: Bob S
authors.initials: BS
authors.lastname: Pond
mesh_terms: D017954:Africa South of the Sahara / Q000453:epidemiology; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008288:Malaria / Q000175:diagnosis / Q000453:epidemiology*; D008297:Male; D008853:Microscopy; D018512:Parasitemia / Q000175:diagnosis / Q000453:epidemiology*; D015995:Prevalence; D014505:Urban Population
references.citation: Malar J. 2006 Nov 09;5:105
references.pmid: 17094806
references.citation: Malar J. 2005 Sep 09;4:40
references.pmid: 16153298
references.citation: Malar J. 2010 Nov 11;9:319
references.pmid: 21067615
references.citation: J Urban Health. 2012 Dec;89(6):977-91
references.pmid: 22684425
references.citation: Trans R Soc Trop Med Hyg. 2000 Mar-Apr;94(2):113-27
references.pmid: 10897348
references.citation: Sante. 2000 Jul-Aug;10(4):267-75
references.pmid: 11111245
references.citation: Acta Trop. 1994 Jun;57(1):91-4
references.pmid: 7942359
references.citation: Am J Trop Med Hyg. 1997 Nov;57(5):550-9
references.pmid: 9392594
references.citation: Trans R Soc Trop Med Hyg. 1987;81 Suppl 2:26-33
references.pmid: 3332057
references.citation: Clin Microbiol Rev. 2002 Jan;15(1):66-78
references.pmid: 11781267
references.citation: J Infect Dis. 2008 Aug 1;198(3):393-400
references.pmid: 18522503
references.citation: J Trop Med Hyg. 1984 Apr;87(2):75-81
references.pmid: 6748132
references.citation: Am J Trop Med Hyg. 2007 Dec;77(6 Suppl):119-27
references.pmid: 18165483
references.citation: Nat Rev Microbiol. 2005 Jan;3(1):81-90
references.pmid: 15608702
references.citation: Am J Trop Med Hyg. 2009 Apr;80(4):547-54
references.pmid: 19346373
references.citation: Am J Trop Med Hyg. 2010 Sep;83(3):465-73
references.pmid: 20810805
references.citation: Bull Soc Pathol Exot. 1997;90(2):94-100
references.pmid: 9289261
references.citation: Am J Trop Med Hyg. 2009 Mar;80(3):487-91
references.pmid: 19270303
references.citation: BMC Public Health. 2010 Jul 29;10:447
references.pmid: 20670448
references.citation: Malar J. 2011 Jun 24;10:173
references.pmid: 21699741
references.citation: Am J Epidemiol. 2004 Apr 1;159(7):702-6
references.pmid: 15033648
references.citation: Parasit Vectors. 2010 Dec 12;3:118
references.pmid: 21143999
references.citation: Am J Trop Med Hyg. 2004 Aug;71(2 Suppl):118-27
references.pmid: 15331827
references.citation: Trop Med Int Health. 2006 May;11(5):578-88
references.pmid: 16640609
references.citation: Malar J. 2005 Sep 16;4:43
references.pmid: 16168054
references.citation: Malar J. 2008 Aug 04;7:151
references.pmid: 18680565
references.citation: Malar J. 2012 Feb 09;11:40
references.pmid: 22321336
references.citation: Acta Trop. 2012 Mar;121(3):166-74
references.pmid: 22119584
references.citation: Med Vet Entomol. 1993 Apr;7(2):127-37
references.pmid: 8481529
references.citation: Am J Trop Med Hyg. 2003 Feb;68(2):169-76
references.pmid: 12641407
references.citation: PLoS Biol. 2004 Nov;2(11):e368
references.pmid: 15510228
references.citation: Int J Equity Health. 2009 Dec 23;8:45
references.pmid: 20030827
references.citation: Acta Trop. 2004 Jan;89(2):125-34
references.pmid: 14732235
references.citation: Malar J. 2009 Jan 13;8:13
references.pmid: 19144144
references.citation: Malar J. 2009 Jun 24;8:138
references.pmid: 19552809
references.citation: Malar J. 2008 Oct 27;7:218
references.pmid: 18954430
references.citation: Trans R Soc Trop Med Hyg. 1987;81 Suppl 2:19-25
references.pmid: 3455564