SCI Foundation is now Unlimit Health. Learn more about what the change means for our ongoing efforts to eliminate neglected tropical diseases

Water, Sanitation & Hygiene (WASH)

The term WASH is used as shorthand for a vast array of infrastructure, behavioural and policy interventions implemented to increase the access to and use of water supply and sanitation services.

What is WASH?

The term WASH is usually applied to households and public settings such as schools and healthcare facilities in low-income contexts where access to these services remains challenging due to poverty, inequality, lack of public funds, and physical and geographic conditions.

WASH mainly refers to:

  • Water: Supplies for drinking and other domestic purposes such as cooking and laundry, and improvements to drinking water quality through water treatment. It tends to exclude water for productive purposes such as agriculture or energy.
  • Sanitation: Access to and use of facilities and services for the safe disposal of human excreta. It is sometimes, although not usually, extended to refer to other waste aspects such as household solid waste. The term applies to the entire ‘chain’ of services related to excreta disposal from toilet capture and containment through emptying, transport, treatment and final disposal or end use.
  • Hygiene: while the term usually refers to conditions and practices to maintain health and prevent disease, in WASH, hygiene focuses on personal cleanliness, often narrowly on hand washing with soap at critical time such as after toilet use and before cooking or eating.
Abebech Shaga, a mother of three, wades into Shapa River in Wolaita Zone, SNNPR to fill her 25 litre jerry can with water which she will take home to wash dishes and for other household chores. Image: Unlimit Health/I. Getachew


These various aspects, separately and as a whole, play a vital role in protecting population health, since inadequate services lead to the spread of harmful pathogens. The most recognised role of WASH for public health is the prevention of infectious diseases, such as diarrhoeal diseases, neglected tropical diseases (see below), vector-borne diseases, and further health consequences such as malnutrition. However, the impact of inadequate WASH on human wellbeing extends to broader aspects such as perpetuating the vicious cycle of disease and poverty, harming educational attainment, and deepening gender and social inequalities.

A mother washes her child in the Bedessa River in Damot Weydie Woreda (district), Wolaita Zone, SNNPR. Wading in the river renders mother and child at risk of contracting Schistosomiasis, or Bilharzia. Freshwater snails that host the Schistosomiasis Monsoni parasite, can be found in waterways like this river. Credit: Unlimit Health/I. Getachew.

WASH and neglected tropical diseases

The control and elimination of NTDs requires a broad set of actions and interventions, including behaviour change, environmental improvement measures, social inclusion efforts and treatment and care services – jointly referred to as the BEST Framework. WASH plays a key role in each of these components:

  • Behaviour: toilet use and maintenance, handwashing, personal hygiene and food hygiene;
  • Environment: construction of safe sanitation systems, water management for vector control, waste disposal (including animal waste);
  • Social inclusion: prevention of stigma in access to WASH services of people with NTDs; WASH for reducing severity of symptoms likely to result in exclusion; and
  • Treatment and care: water supply, sanitation and hygiene in healthcare settings and at home for self-care and rehabilitation of affected individuals.

The role of WASH in NTD elimination has been recognised by the WHO in the 2030 NTD road map and the publication of a Global Strategy on WASH and NTDs.

Lifecycle of schistosomiasis, from eggs, to snails, to water, to humans.

Prevention of parasitic worm infections

The transmission of parasitic infections such as soil-transmitted helminths (STH) and schistosomiasis is fundamentally linked to inadequate provision of WASH services and failures in the service chain.

In the case of STH, parasite eggs are excreted in the faeces of infected individuals. In the absence of adequate sanitation (resulting in open defecation practices) or due to other failures such as inadequate containment or end use (such as use of untreated waste as manure on crops), these eggs mature in the soil and go on to infect other individuals. Lack of good hygiene practices, and the water supplies to sustain them, result in ingestion of eggs and the infection of new hosts. Hookworm infections occur in the absence of shoe-wearing in contaminated environments. Infective helminth eggs can also be consumed in contaminated drinking water.

Schistosomiasis transmission occurs when eggs are excreted through the faeces or urine of infected individuals in or near surface water when the intermediate snail hosts are present. WASH plays a fundamental role in both preventing the transmission and the exposure to the disease. For transmission prevention, sanitation services can prevent or reduce defecation in or near surface water; while safe water supplies that cover all household needs can reduce exposure to contaminated surface water.

What Unlimit Health is doing

Unlimit Health understands the need for a comprehensive intervention package for the prevention of parasitic worm infections. While the implementation of WASH interventions falls under the responsibility of government agencies and other expert organisations, Unlimit Health can play an important role in both enhancing the effectiveness of WASH interventions for disease prevention, and the targeting of such interventions to high-prevalence areas.


The manmade dam in Shone Woreda traps water from the previous rainy season which the local community uses for washing clothes, bathing, swimming, taking home for household chores, as well as to provide water for their cattle. The pond is also home to freshwater snails that host schistosomiasis/bilharzia. Access to clean piped water, or even water from a clean protected source, is limited. Image: Unlimit Health/I. Getachew

Community-led WASH project in Uganda

Since July 2020, Unlimit Health has been collaborating with partners on a pilot project in three communities with a high prevalence of schistosomiasis infection in Kamuli district, Eastern Uganda.

The pilot tested approaches and methods to enhance community innovation and participation in health protection measures. Additionally, it provided insights for further collaboration between Unlimit Health and partners for disease prevention.

The project partners are now working to deliver key water supply, sanitation and health promotion interventions identified in the community action plans of the three communities who participated in the pilot. The project will start the process of producing community-led analyses of schistosomiasis transmission in three additional communities.


Our approach to water, sanitation and behaviour change

An approach paper has been developed by the Unlimit Health to inform its engagement with Ministries of Health in schistosomiasis-endemic countries, as well as to inform debate and development of preferred practices within the global schistosomiasis community. This is an emerging approach, which will continue evolving as Unlimit Health expands its work in this area and as the various components set out in the document are applied and evaluated in the programmatic context.

Read the Unlimit Health WASH discussion paper


Cover of 'WASH and health working together: a ‘how-to’ guide for neglected tropical disease programmes'

World Health Organization WASH and NTDs toolkit

Staff at Unlimit Health have worked as part of the NTD NGO Network (NNN)’s water, sanitation and hygiene (WASH) working group alongside the World Health Organization (WHO).

The WHO’s 2021 global strategy on WASH to combat neglected tropical diseases addresses the need for a joint approach between WASH and NTD programmes to ensure that investments in WASH reached the people most in need. Collaborative approaches across different sectors can be challenging when professionals from these sectors have separate budgets, work in separate countries and have different objectives. The collaboration between WHO and the NNN is a direct response to this challenge, putting the theory behind the global strategy into practice.

The two organisations drew on practical experiences and tested methods to create “WASH and health working together: a ‘how to’ guide for NTD programmes”. This is a step-by-step document aiming:

  • To build partnerships between local WASH agencies, businesses and groups, local health groups, behaviour change and communication experts.
  • To build an adaptive and flexible approach to programming.
  • To ensure the sustainability of programmes.
  • To support clinical and public health interventions for NTD control.

The toolkit aims to provide clear, easy to follow steps from agreeing a joint vision, to joint implementation. It will help us to aid governments in building partnerships with key stakeholders (including national and local agencies, behaviour change experts and local health groups) and to shape an adaptive approach to programming in unserved populations.