WHO publishes 54 pathogen background documents to support safe water and sanitat
2025-06-26
In a move to strengthen global efforts against waterborne disease, WHO has released 54 WASH-related pathogens new technical background documents - announced yesterday at a global water microbiology conference in the Netherlands - that capture the latest science on pathogens linked to drinking-water and sanitation systems.
Unsafe water, inadequate sanitation and poor hygiene (WASH) continue to expose billions of people to harmful pathogens every day. These systemic failures are responsible for more than 1.4 million preventable deaths each year, disproportionately affecting young children.
The newly published documents offer a detailed overview of pathogens that pose a risk through water, sanitation, or both. WHO has included documents for several pathogens not traditionally considered waterborne, but for which questions have been raised about possible transmission through drinking-water.
Each background document provides a concise summary of the current science. This includes information on human health impacts, disease patterns, modes of transmission, and sources of faecal contamination.
The profiles also detail how these pathogens occur in the environment - including in various parts of the water cycle - and how they are detected, prevented, and managed within drinking-water and sanitation systems.
The technical package also features a list of the top 10 water- and sanitation-related pathogens, developed to spotlight priority threats, raise awareness and support clear communication of the evidence and actions outlined in the background documents. Well-managed sanitation and drinking-water systems will effectively control WASH-related pathogens, including these top 10.
This summary, along with the background documents, is being launched at WaterMicro25, the 22nd Health Related Water Microbiology Conference today, in the Netherlands.
Based on burden of disease data, evidence of WASH transmission and concerns such as antimicrobial resistance, the Top 10 pathogens include diarrhoea genic and enterohaemorrhagic Escherichia coli, Vibrio cholerae, Salmonella spp., Shigella, Campylobacter, Cryptosporidium, rotavirus, norovirus, adenovirus and hepatitis A.
“We know what’s making people sick and we know how to stop it,” said Bruce Gordon, Head of WHO’s Water, Sanitation, Hygiene and Health Unit.
“Safe drinking-water, sanitation systems and strong regulations are the foundation for public health - yet millions still lack access to them. A key is for all countries to work within their means and make gradual improvements within their systems to stop these pathogens.”
A global problem, a preventable burden
Many of these pathogens are transmitted not just through drinking-water, but also through contaminated food, hands and the environment. Poorly managed sanitation systems, unreliable water supply and exposure to animal waste all contribute to transmission.
Although vaccines exist for some of these diseases - including cholera, rotavirus, typhoid and hepatitis A - most remain preventable only through long-term WASH investments, such as:
water safety planning
The WHO Guidelines for drinking-water quality recommend water safety plans (WSPs) as the most effective means of consistently ensuring the safety and acceptability of a drinking-water supply.
WSPs require a risk assessment including all steps in water supply from catchment to consumer, followed by implementation and monitoring of risk management control measures, with a focus on high priority risks.
Where risks cannot be immediately addressed, the WSP approach allows for incremental improvements to be implemented systematically over time. WSPs should be implemented within a public health context, responding to clear health-based targets and quality-checked through independent surveillance.
WSPs are adaptable to all types and sizes of water supply, and can be effectively applied in all socioeconomic settings. The water safety planning approach is increasingly being adopted globally as best practice for the provision of safe drinking-water.
Sanitation Safety Planning
Sanitation safety planning (SSP) is the approach recommended by WHO to support the implementation of the Guidelines on sanitation and health and guidelines on safe use of wastewater, excreta and greywater at the local level. This second edition includes updates to simplify the SSP process, align with the guidelines on sanitation and health for all systems with or without a safe end use step, and incorporate climate risks.
SSP is a risk-based management tool for sanitation systems that:
helps with systematically identifying and prioritizing health risks along the sanitation chain - that is, toilet, containment?storage/treatment, conveyance, treatment, and end use or disposal.
guides management and investments in sanitation systems according to risk.
identifies operational monitoring priorities and regulatory oversight mechanisms that target the highest risks; and provides assurance to authorities and the public on the safety of sanitation-related products and services.
Wastewater and environmental surveillance
Wastewater and environmental surveillance (WES) is disease surveillance using samples from sewage, or other environmental waters impacted by human wastewater. WES has potential to provide information alongside other forms of disease surveillance to fill gaps in other surveillance data and inform the public health response. WES has been successfully used for many years in the polio eradication programme and more recently in the COVID-19 pandemic response.
WHO is working on guidance and capacity development for WES, for one or more pathogen, as part of a collaborative surveillance approach with a focus on guiding WES investment to targets where; WES data provides actionable information for significant public health challenges in the local context, where methods are technically and operationally feasible, where WES is ethically and legally acceptable, and where WES can be effectively optimized though integration with other targets and clinical surveillance.
Pilot versions of the pathogen agnostic prioritization guidance and the first six WES pathogen summary sheets can be downloaded below (in English, French, Russian and Spanish).
“Effective WASH, which can stop all pathogens, is an essential complement to vaccination,” said Dr Sophie Boisson, Lead Epidemiologist in WHO’s Water, Sanitation and Hygiene Unit. “Effective WASH provides the multiple barriers that stop transmission of over 50 waterborne pathogens - viruses, bacteria and protozoan parasites.”
WHO’s call to action
The background documents are supporting information for WHO’s Guidelines on sanitation and health and/or the Guidelines for drinking-water quality. They are intended to help public health practitioners assess and manage risks in water and sanitation systems more effectively.
WHO supports countries to develop WASH standards, build workforce capacity and monitor progress through global efforts such as the WHO/UNICEF Joint Monitoring Programme for Water Supply, Sanitation and Hygiene (JMP) and the UN-Water Global Analysis and Assessment of Sanitation and Drinking-Water (GLAAS).
By identifying the pathogens that matter most - and the systems that can stop them - WHO aims to strengthen disease prevention from the ground up.
“It’s time to align public health strategies with water and sanitation realities,” added Boisson. "Without addressing the root causes of pathogen transmission, we will keep responding to outbreaks rather than preventing them."
[출처 = 세계보건기구(WHO)(https://www.who.int/news/item/21-06-2025-who-publishes-54-pathogen-background-documents-to-support-safe-water-and-sanitation-systems) / 2025년 6월 21일]
