Public health and development: Infrastructure, social norms, and health behaviours

6 Case studies

As discussed in Section 2, efforts to increase WASH coverage in low-income countries are falling short of what is required to achieve the Sustainable Development Goals. There have been some successful specific interventions, and some interventions that failed to achieve better health outcomes. This section presents four case studies that identified a causal link between the intervention and the health outcomes: WASH interventions, behavioural change campaigns, privatized water and sewerage services, and campaigns to overcome vaccine hesitancy.

Complementarities and externalities in WASH interventions

Waterborne diseases are health conditions caused by pathogenic microorganisms that are transmitted by water. The most common waterborne diseases are diarrhoea and skin, ear, eye, and respiratory infection. The pathogens are spread while bathing, washing, or drinking water, or by eating food exposed to contaminated water. They are a major cause of death in developing countries. To learn more about transmission pathways, read Hugh Waddington and Birte Snilstveit. 2009. ‘Effectiveness and Sustainability of Water, Sanitation, and Hygiene Interventions in Combating Diarrhoea’. Journal of Development Effectiveness 1(3): pp. 295–335.

Lack of clean water supply, sanitation, and hygiene (WASH) are major causes for the spread of waterborne diseases in a community. There are many pathways to transmission of waterborne diseases, and these pathways are affected by complementarities and external effects.

complements

Two goods for which an increase in the price of one leads to a decrease in the quantity demanded of the other. See also: substitutes.

Complementarities between water and sanitation exist when water is needed to keep latrines functioning: use of a latrine may be discouraged if it is in a poor condition (for example, due to high maintenance costs). There is evidence of short-term use of latrines while they are new, but failure to keep them functional causes a decline in use after this initial boost. External effects (externalities) emerge in the context of water contamination. For example, shallow wells can be contaminated by human faeces from OD practices.

Successful sanitation campaigns need to account for both complementarities and external effects. One example is an intervention that provided universal access to latrines and piped water to a whole community in a sample of 100 communities in the state of Orissa, one of India’s poorest, in the 1990s to early 2000s.^1 2 The programme was implemented only when 100% of the households in the community agreed to pay a subsidized fee. The cost amounted to US$60 per household per year, roughly three times the investment of the Swachh Bharat Mission Clean India Campaign per household. As the authors state: ‘The design of the program we evaluate takes externalities and complementarities seriously: Infrastructure is built to ensure that every household in the village is connected to a local water and sanitation network, and every household is provided with a pour flush toilet and piped water, with taps in the home and the toilet.’¹ This is not very common in rural WASH interventions, where take-up and/or coverage are seldom universal, and most interventions are not integrated to provide both water and sanitation solutions. While many sanitation campaigns have failed to show positive health results, complementing water provision with toilets resulted in a significant (30–50%) reduction of diarrhoea episodes persisting even after five years. Besides the reduction in diarrhoea, the study also finds improvements in malaria and fever, albeit smaller in magnitude. These improvements may also be linked to improved sanitation, as better water management can help prevent malaria-spreading mosquitoes from breeding.

Pure behavioural change campaign in rural Mali

According to the WHO, stunting is the impaired growth and development that children experience from poor nutrition, repeated infection, and inadequate psychosocial stimulation. Children are defined as stunted if their height-for-age is more than two standard deviations below the WHO Child Growth Standards median.

Stunting in early life—particularly in the first 1,000 days from conception until the age of two—has adverse functional consequences on the child. Some of those consequences include poor cognition and educational performance, low adult wages, lost productivity and, when accompanied by excessive weight gain later in childhood, an increased risk of nutrition-related chronic diseases in adult life.

In rural Mali, a well-implemented Community-Led Total Sanitation (CLTS) programme contributed to the reduction in child stunting, though had no effect on diseases such as diarrhoea.³ Such results are interesting because CLTS has often failed to show consistent health or growth effects.

The adoption of unimproved pit latrines can be easier in contexts of low population density and favourable climate conditions (drier weather).

CLTS is the main and only approach to rural sanitation in Mali. Mali is one of the poorest countries in the world and its government lacks resources to invest in health-related infrastructure so, with the help of UNICEF, they implemented CLTS to eliminate OD in rural areas. The version of CLTS implemented was as close to the textbook version as possible, with no subsidies and very close and continued monitoring of latrine construction. Latrines were very simple pit latrines that were relatively cheap to build. Latrine usage doubled (from 33% to 66%), and handwashing behaviour improved. CLTS succeeded because it helped establish new social norms. Individuals surveyed before the start of the CLTS campaign were already aware of the positive aspects of a clean environment, so the campaign worked as a way to coordinate expectations and solve collective action problems at the community level.^4 5

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Pit latrine in rural Mali built under the CLTS programme.

Privatizing water and sewerage services: Does it harm the poor?

The privatization of piped drinking water and sewerage services might affect child health through several channels. However, the net effect (positive or negative) is difficult to predict: while privatization can create efficiency gains, improving both access to water and its quality, it may do so at a higher price, reducing the access of poorer community members. Additionally, if the positive health external effects of clean water provision are not considered, the service will be underprovided.

A study of the privatization of water services in Argentina during the 1990s found that it reduced child mortality by 26%.⁶ This reduction largely took place in poorer districts, which experienced a greater increase in access to water and had higher child mortality rates to begin with. The fall in mortality was due to a combination of network expansion and better bacteriological content of the water. While the unit price of the service did not increase by much after privatization, the initial connection fees—roughly equivalent to the poverty line income—were high. Protests by users caused the fees to drop to one-tenth of the original privatized price. The lower connection fee was cross-subsidized by a fixed fee applied to each water bill. Privatization also increased investment in infrastructure works in water provision (such as new pipes connecting households to the network) and sewerage, and led to efficiency gains.

Vaccine hesitancy: Eradicating polio in India

By the start of the twenty-first century, most countries around the world had eradicated polio, starting with OECD countries and followed by the rest of the world. However, as of 2024, wild polio was present in two countries, with less than 100 cases (25 in Afghanistan and 70 in Pakistan), and polio circulation was still present in countries such as Yemen and Somalia.

India was certified as ‘polio free’ by the WHO in 2014. Eradication of polio in India was a challenge because of its size and environmental conditions. While the scientific solution to eradicating polio had been available for years, complete eradication of the disease by means of vaccines in India required overcoming ‘barriers to vaccination that were deeply rooted in larger issues of social trust and political vulnerability’.⁷ The main challenges were vaccine hesitancy in very poor groups and religious minorities in areas such as the state of Uttar Pradesh. Additionally, health infrastructure in such areas was rudimentary. Building trust with local leaders was also a key factor. For example, UNICEF engaged with academics and scholars to develop pro-vaccine arguments that drew on religious literature and local beliefs. Vaccine acceptance improved when packaging the polio vaccine with a bulk of other healthcare services such as routine check-ups and basic medications. Influential community leaders, such as Islamic scholars and members of religious and academic organizations, were involved to reach vaccine-hesitant groups.