Pathogens found in excreta (e.g. bacteria, viruses, worms and protozoa) can spread diarrhoea and many other diseases. The F-Diagram [A.2] is a tool that illustrates the main transmission routes and the potential barriers to prevent faecal-oral transmission.

Understanding the routes through which an individual can become infected helps to target interventions to reduce the spread of disease. The F-Diagram is one of the many tools in the Participatory Hygiene and Sanitation Transformation F.6 approach; it has been used in multiple contexts and with other programme approaches to explain disease transmission. The F-Diagram provides a visual explanation and illustrates the main transmission routes of pathogens from the faeces of one infected person to another. Transmission can occur via Fluids (e.g. contaminated water), people’s Fingers, Flies, via Fields where open defecation is prevalent and via Food that is unwashed, uncooked, inadequately cooked or uncovered. Since all these paths start with the letter F they are easily memorised. Additional pathways include ‘floods’ where contaminated water can easily spread pathogens and ‘fomites’ that carry a disease (e.g. household surfaces, materials and objects). It can be useful to consider animal as well as human faeces. The diagram illustrates possible barriers and interventions that can impede transmission. Barriers such as improved sanitation (where faeces are safely contained), handwashing with soap, food hygiene, water treatment and protection of the water source can prevent an initial contact with faeces (primary barrier) or help to prevent faeces being ingested by another person (secondary barrier). Participants are often provided with individual pictures and asked to construct the diagram and transmission routes for themselves. As with most interactive activities, facilitators need to enable the participants to discuss freely whilst being knowledgeable and confident about the transmission routes.

Applicability

The F-Diagram can be used in various ways for training and problem-solving with community members, WASH personnel and other humanitarian actors. It is appropriate in a variety of contexts and can be used with different age groups, including children, in all phases of the response and stages of the project cycle.

Do

• Use the tool interactively to enable a variety of stakeholders to understand Transmission Routes

• Use picture cards or posters [T.19] or make use of locally available materials to visualise transmission routes 

• Apply the transmission routes to the specific context and encourage participants to engage in problem solving

Don't

• Do not rush the activity as it can take time for people to digest and learn the transmission routes

• Do not use the whole diagram with groups that are unfamiliar with visual images –break it down into sections

Practical Example

In a WASH programme in Ghana, the F-Diagram was particularly useful coupled with Community Mapping T.7 as it enabled the community members, including children, to understand how their food and water sources became contaminated and to discuss the health and cost implications. This helped to create demand for safe drinking water and household and institutional latrine facilities in all the surrounding villages.