A city-wide sewerage installation reduced diarrhea prevalence among children by 22% in the city of Salvador, Brazil. An article in The Lancet explains why urban sanitation, as an extremely valuable health measure, cannot be disregarded.
The authors explain that the importance of good water supply and hygiene for preventing diarrheal diseases and other infections was established by the international community when coverage goals were included in the MDGs (Millennium Development Goals).
Sanitation appears to be as effective as adequate water supply when the goal is better public health. The promotion of sanitation combined with hygiene is one of the most cost-effective interventions against high-burden disease in developing nations, the authors write.
An intervention started in the city of Salvador in 1997 to raise sewerage from 26% of homes to 80%.
Professor Mauricio Barreto, Instituto de Saude Coletiva, Federal University of Bahia, Salvador, Brazil, and team carried out two studies of children aged up to 36 months. The first study took place before the intervention in 1997-1998, involving 841 children. The second study occurred in 2003-2004, after the intervention was completed, and involved 1,007 children. The children were randomly sampled from 24 areas – the aim was to represent the range of conditions in the city. Homes were visited twice a week to gather diarrhea data.
The researchers found that the prevalence of diarrhea among children dropped by 21% after the sanitation program. After adjustments for baseline sewerage coverage and potential variables were made, the estimated prevalence reduction was estimated to be 22%. Where baseline diarrhea was highest the reduction reached 43%.
“Because sewerage is mainly external to houses and the fact that it prevents disease transmission in the public domain, public responsibility is to ensure that sewerage is installed. At a typical cost per person of $160, investment in sewerage is too large to be left to cash-strapped municipalities, and needs the involvement of international organizations, and central government and its agencies. The health sector is not generally an investor, but it nevertheless has a key part to play, through promotion, advocacy, and regulation, to ensure that toilets and sewers are properly built, used, and maintained, so that their full health benefits are realized by all,” the researchers said.
“Our results show that urban sanitation is a highly effective health measure that can no longer be ignored, and they provide a timely support for the launch of 2008 as the International Year of Sanitation,” the authors concluded.
Accompanying Comment
Dr David Durrheim, Hunter New England Population Health, Newcastle, NSW, and James Cooke University, Townsville, QLD, Australia, wrote “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 Assembly 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 diarrhea due to poor sanitation.”
Linked Editorial
“Adequate sanitation is the most effective public-health intervention the international community has at its disposal. Yet 40% of the world’s population still lacks access to a toilet. It is time for toilets and sewage disposal systems to be taken more seriously, not just by governments and civil society, but also by funding bodies and the global health community,” concluded a Linked Editorial.
Article
“Effect of city-wide sanitation programme on reduction in rate of childhood diarrhoea in northeast Brazil”
M L Barreto et al
Accompanying Comment
“Reduction of maternal depression: much remains to be done”
R Small, J Lumley
The Lancet Volume 370 • Number 9599 • November 10-16, 2007
(spelling׃ USA – Diarrhea. UK – diarrhoea)
Written by׃ Christian Nordqvist