[DEBATE] : A clarion call for greater investment in global sanitation
rose_pete at aapt.net.au
Sat Nov 24 08:01:14 GMT 2007
The Lancet 2007; 370:1592-1593
A clarion call for greater investment in global sanitation
There were 236896 cholera cases with 6311 deaths notified from 52 countries to WHO in 2006.1 This represents a 79% increase in cases compared with 2005; a level last seen in the 1990s. These sobering statistics expose a global tragedy, because the occurrence of cholera is a sensitive indicator of inequity.2 Communities which depend on a water supply that is potentially contaminated with human faeces remain very vulnerable to this faeco-orally transmitted infectious disease.
Vibrio cholerae is only one of many infectious agents that thrive in contaminated water supplies, and which are a source of misery, driving poverty in many communities in developing countries. Diarrhoeal disease continues to be a leading cause of death in these countries, particularly affecting children in the first 5 years of life.3 The hindrance on global development resulting from inadequate sanitation is recognised in the Millennium Development Goals (MDGs), and an aspirational target to halve the proportion of people without access to basic sanitation by 2015 has been established. Accomplishment of this target would profoundly reduce the risk of cholera and other epidemic-prone diarrhoeal diseases. Although global sanitation coverage increased from 49% to 59% between 1990 and 2004, on the basis of current performance the shortfall will be almost 600 million people by the target date in 2015.4
The vigour with which other MDGs have been approached has not yet been mirrored in tackling the sanitation shortfall. Indeed, in sub-Saharan Africa the number of people with unsafe sanitation is increasing.4 There seems to be political reluctance to invest in the safe disposal of human faeces, with this function often delegated to the lowest level of governance (ie, struggling municipalities). Surprisingly, a meagre evidence base supports the health benefits of improved sanitation in populations.5 Rigorous science is a valuable method for persuasive advocacy.
Against this backdrop, Mauricio Barreto and colleagues' study, in today's Lancet, of the effect of a large-scale urban sanitation programme in north east Brazil provides remarkable supportive evidence for increasing access to this basic health right.6 This study bolsters the public-health evidence for a neglected intervention, transcending the gulf between small-scale efficacy or limited observational studies and population-level evidence. The authors report the results of two large population-based observational studies on occurrence of diarrhoea with or without a sanitation intervention.
Although the design was not randomised, and the challenging research environment introduced some imprecision so that the possibility of confounding cannot be absolutely excluded, these points do not detract from the convincing finding that the sanitation intervention reduced longitudinal diarrhoeal prevalence in children younger than 3 years by a noteworthy 22% (95% CI 19-26).
An estimated 1·6 billion people will need access to improved sanitation over the period 2005-15 to meet the MDG target, and the UN General Assembly7 has declared 2008 an International Year of Sanitation. The obvious benefits to poor people of increased provision of sewerage facilities should serve as the mandate for greater investment by all levels of government and civil society in tackling one of the greatest scourges to communities in developing countries-infectious diarrhoea due to poor sanitation.
I declare that I have no conflict of interest.
1. WHO. Cholera 2006. Wkly Epidemiol Rec 2007; 31: 273-284.
2. Durrheim DN. Prevention of cholera. Lancet 2004; 363: 897-898. Full Text | Full-Text PDF (44 KB) | CrossRef
3. Kosek M, Bern C, Guerrant RL. The global burden of diarrhoeal disease, as estimated from studies published between 1992 and 2000. Bull World Health Organ 2003; 81: 197-204. MEDLINE
4. UN. Millennium development goals report 2007. 2007:
(accessed Oct 17, 2007)..
5. Fewtrell L, Kaufmann RB, Kay D, Enanoria W, Haller L, Colford JM Jr. Water, sanitation, and hygiene interventions to reduce diarrhoea in less developed countries: a systematic review and meta-analysis. Lancet Infect Dis 2005; 5: 42-52. Abstract | Full Text | Full-Text PDF (125 KB) | MEDLINE | CrossRef
6. Barreto ML, Genser B, Strina A, et al. Effect of city-wide sanitation programme on reduction in rate of childhood diarrhoea in northeast Brazil: assessment by two cohort studies. Lancet 2007; 370: 1622-1628. Abstract | Full Text | Full-Text PDF (152 KB)
7. UN. Resolution A/C.2/61/L.16/Rev. United Nations. Dec 4, 2006:
(accessed Nov 6, 2007)..
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