Fecal–oral route

The foundations for the "F-diagram" being used today were laid down in a publication by the World Health Organization (WHO) in 1958.[6] This publication explained transmission routes and barriers to the transmission of diseases from the focal point of human feces.

Modifications have been made over the course of history to derive modern-looking F-diagrams. These diagrams are used in many sanitation publications.[7] They are set up in a way that fecal–oral transmission pathways are shown to take place via water, hands, arthropods and soil. To make it easier to remember, words starting with the letter "F" are used for each of these pathways, namely fluids, fingers, flies, food, fields, fomites (objects and household surfaces).

Rather than only concentrating on human feces, animal feces should also be included in the F-diagram.[7]

The sanitation and hygiene barriers when placed correctly prevent the transmission of an infection through hands, water and food. The F-diagram can be used to show how proper sanitation (in particular toilets, hygiene, handwashing) can act as an effective barrier to stop transmission of diseases via fecal–oral pathways.

The process of transmission may be simple or involve multiple steps. Some examples of routes of fecal–oral transmission include:

• water that has come in contact with feces (for example due to groundwater pollution from pit latrines) and is then not treated properly before drinking;
• by shaking someone's hand that has been contaminated by stool, changing a child's diapers, working in the garden, or dealing with domestic animals.
• food that has been prepared in the presence of fecal matter;
• eating soil (geophagia)
• disease vectors, like houseflies, spreading contamination from inadequate fecal disposal such as open defecation;
• poor or absent hand washing after using the toilet or changing diapers;
• poor or absent cleaning of anything that has been in contact with feces;
• sexual practices that may involve oral contact with feces, such as anilingus ("Rimjobs"), coprophilia or A2M sexual intercourse.
• eating feces, in children, or in a mental disorder called coprophagia

Modified F-diagram including interventions that can block human exposure to animal feces.[7]

One approach to changing people's behaviors and stopping open defecation is the community-led total sanitation approach. In this process "live demonstrations" of flies moving from food to fresh human feces and back are used. This can "trigger" villagers into action.[8]

• Vibrio cholerae (cholera)
• Clostridium difficile (pseudomembranous enterocolitis)
• Shigella (shigellosis / bacillary dysentery)[9]
• Salmonella typhii (typhoid fever)[10]
• Vibrio parahaemolyticus[11]
• Escherichia coli[12]
• Campylobacter[13]

• Hepatitis A[14]
• Hepatitis E[15]
• Enteroviruses
• Norovirus acute gastroenteritis
• Poliovirus (poliomyelitis)
• Although most human Coronaviruses are not transmitted fecally (Feline coronavirus, in contrast, is), there have also been reports of SARS-CoV-2 being found in stool samples.[16][17]
• Rotavirus gastroenteritis
• Adenovirus gastroenteritis

• Entameba histolytica[12] (amoebiasis / amoebic dysentery)
• Giardia (giardiasis[18])
• Cryptosporidium (cryptosporidiosis)
• Toxoplasma gondii[13] (toxoplasmosis)

• Tapeworms[12]
• Soil-transmitted helminths

Waterborne diseases are diseases caused by pathogenic microorganisms that most commonly are transmitted in contaminated fresh water. This is one particular type of fecal-oral transmission.

Neglected tropical diseases also include many diseases transmitted via the fecal-oral route.