Fecal–oral route

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The "F-diagram" (feces, fingers, flies, fields, fluids, food), showing pathways of fecal-oral disease transmission. The vertical blue lines show barriers: toilets, safe water, hygiene and handwashing. F-diagram-01.jpg
The "F-diagram" (feces, fingers, flies, fields, fluids, food), showing pathways of fecal–oral disease transmission. The vertical blue lines show barriers: toilets, safe water, hygiene and handwashing.

The fecal–oral route (also called the oral–fecal route or orofecal route) describes a particular route of transmission of a disease wherein pathogens in fecal particles pass from one person to the mouth of another person. Main causes of fecal–oral disease transmission include lack of adequate sanitation (leading to open defecation), and poor hygiene practices. If soil or water bodies are polluted with fecal material, humans can be infected with waterborne diseases or soil-transmitted diseases. Fecal contamination of food is another form of fecal-oral transmission. Washing hands properly after changing a baby's diaper or after performing anal hygiene can prevent foodborne illness from spreading.

Contents

The common factors in the fecal-oral route can be summarized as five Fs: fingers, flies, fields, fluids, and food. Diseases caused by fecal-oral transmission include diarrhea, typhoid, cholera, polio and hepatitis.

Background

Villagers during a CLTS triggering exercise go to the place where meals are prepared to observe how flies are attracted to human feces and carry diseases by landing on the food (village near Lake Malawi, Malawi) Actions to end open defecation in a village in Malawi (2).jpg
Villagers during a CLTS triggering exercise go to the place where meals are prepared to observe how flies are attracted to human feces and carry diseases by landing on the food (village near Lake Malawi, Malawi)
School children during a CLTS triggering event in West Bengal, India looking at a glass of water and fresh human feces where the flies pass from the water to the feces and back. This demonstrates how water can get polluted with pathogens. CLTS triggering in Malda District, West Bengal, India.JPG
School children during a CLTS triggering event in West Bengal, India looking at a glass of water and fresh human feces where the flies pass from the water to the feces and back. This demonstrates how water can get polluted with pathogens.

Although fecal–oral transmission is usually discussed as a route of transmission, it is actually a specification of the entry and exit portals of the pathogen, and can operate across several of the other routes of transmission. [1] Fecal–oral transmission is primarily considered as an indirect contact route through contaminated food or water. However, it can also operate through direct contact with feces or contaminated body parts, such as through anal sex. [2] [3] It can also operate through droplet or airborne transmission through the toilet plume from contaminated toilets. [4] [5]

F-Diagram

The foundations for the "F-diagram" being used today were laid down in a publication by 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.

Examples

Transmission

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

Prevention

Modified F-diagram including interventions that can block human exposure to animal feces. Modified F-Diagram.jpg
Modified F-diagram including interventions that can block human exposure to animal feces.

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]

Diseases

The list below shows the main diseases that can be passed via the fecal–oral route. They are grouped by the type of pathogen involved in disease transmission.

Bacteria

Viruses

Protozoans

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 contains many diseases transmitted via the fecal-oral route.

See also

Related Research Articles

Cholera Bacterial infection of the small intestine

Cholera is an infection of the small intestine by some strains of the bacterium Vibrio cholerae. Symptoms may range from none, to mild, to severe. The classic symptom is large amounts of watery diarrhea that lasts a few days. Vomiting and muscle cramps may also occur. Diarrhea can be so severe that it leads within hours to severe dehydration and electrolyte imbalance. This may result in sunken eyes, cold skin, decreased skin elasticity, and wrinkling of the hands and feet. Dehydration can cause the skin to turn bluish. Symptoms start two hours to five days after exposure.

Trichuriasis Infection by the parasitic worm Trichuris trichiura (whipworm)

Trichuriasis, also known as whipworm infection, is an infection by the parasitic worm Trichuris trichiura (whipworm). If infection is only with a few worms, there are often no symptoms. In those who are infected with many worms, there may be abdominal pain, tiredness and diarrhea. The diarrhea sometimes contains blood. Infections in children may cause poor intellectual and physical development. Low red blood cell levels may occur due to loss of blood.

Hygiene set of practices performed for the preservation of health

Hygiene is a series of practices performed to preserve health. According to the World Health Organization (WHO), "Hygiene refers to conditions and practices that help to maintain health and prevent the spread of diseases." Personal hygiene refers to maintaining the body's cleanliness.

Sanitation public health conditions related to clean drinking water and adequate disposal of human excreta and sewage

Sanitation refers to public health conditions related to clean drinking water and adequate treatment and disposal of human excreta and sewage. Preventing human contact with feces is part of sanitation, as is hand washing with soap. Sanitation systems aim to protect human health by providing a clean environment that will stop the transmission of disease, especially through the fecal–oral route. For example, diarrhea, a main cause of malnutrition and stunted growth in children, can be reduced through adequate sanitation. There are many other diseases which are easily transmitted in communities that have low levels of sanitation, such as ascariasis, cholera, hepatitis, polio, schistosomiasis, and trachoma, to name just a few.

El Tor is a particular strain of the bacterium Vibrio cholerae, the causative agent of cholera. Also known as V. cholera biotype eltor, it has been the dominant strain in the seventh global cholera pandemic. It is distinguished from the classic strain at a genetic level, although both are in the serogroup O1 and both contain Inaba, Ogawa and Hikojima serotypes. It is also distinguished from classic biotypes by the production of hemolysins.

Ingestion is the consumption of a substance by an organism. In animals, it normally is accomplished by taking in a substance through the mouth into the gastrointestinal tract; such as through eating or drinking. In single-celled organisms ingestion takes place by absorbing a substance through the cell membrane.

Transmission (medicine) Passing of a pathogen from one organism to another

In medicine, public health, and biology, transmission is the passing of a pathogen causing communicable disease from an infected host individual or group to a particular individual or group, regardless of whether the other individual was previously infected.

Human waste refers to the waste products of the human digestive system and the human metabolism, namely feces and urine. As part of a sanitation system that is in place, human waste is collected, transported, treated and disposed of or reused by one method or another, depending on the type of toilet being used, ability by the users to pay for services and other factors. Fecal sludge management is used to deal with fecal matter collected in on-site sanitation systems such as pit latrines and septic tanks.

<i>Hymenolepis nana</i> species of worm

Dwarf tapeworm is a cosmopolitan species though most common in temperate zones, and is one of the most common cestodes infecting humans, especially children.

<i>Vibrio parahaemolyticus</i> species of bacterium

Vibrio parahaemolyticus is a curved, rod-shaped, Gram-negative bacterium found in brackish, saltwater, which, when ingested, causes gastrointestinal illness in humans. V. parahaemolyticus is oxidase positive, facultatively aerobic, and does not form spores. Like other members of the genus Vibrio, this species is motile, with a single, polar flagellum.

<i>Phlebotomus</i> genus of insects

Phlebotomus is a genus of "sand flies" in the Diptera family Psychodidae. In the past, they have sometimes been considered to belong in a separate family, Phlebotomidae, but this alternative classification has not gained wide acceptance.

<i>Cryptosporidium</i> genus of apicomplexan parasitic alveolate

Cryptosporidium, sometimes informally called crypto, is a genus of apicomplexan parasitic alveolates that can cause a respiratory and gastrointestinal illness (cryptosporidiosis) that primarily involves watery diarrhea with or without a persistent cough in both immunocompetent and immunodeficient humans.

<i>Pasteurella</i> genus of bacteria

Pasteurella is a genus of Gram-negative, facultatively anaerobic bacteria. Pasteurella species are nonmotile and pleomorphic, and often exhibit bipolar staining. Most species are catalase- and oxidase-positive. The genus is named after the French chemist and microbiologist, Louis Pasteur, who first identified the bacteria now known as Pasteurella multocida as the agent of chicken cholera.

Yersiniosis is an infectious disease caused by a bacterium of the genus Yersinia. In the United States, most yersiniosis infections among humans are caused by Yersinia enterocolitica.

<i>Campylobacter fetus</i> species of bacterium

Campylobacter fetus is a species of Gram-negative, motile bacteria with a characteristic "S"-shaped rod morphology similar to members of the genus Vibrio. Like other members of the genus Campylobacter, C. fetus is oxidase-positive.

<i>Histoplasma</i> genus of fungi

Histoplasma is a genus of dimorphic fungi commonly found in bird and bat fecal material. Histoplasma contains a few species, including—Histoplasma capsulatum—the causative agent of histoplasmosis; and Histoplasma capsulatum var. farciminosum, causing epizootic lymphangitis in horses.

Amoebiasis Human disease caused by amoeba protists

Amoebiasis, also known amoebic dysentery, is an infection caused by any of the amoebae of the Entamoeba group. Symptoms are most common during infection by Entamoeba histolytica. Amoebiasis can be present with no, mild, or severe symptoms. Symptoms may include abdominal pain, diarrhea, or bloody diarrhea. Complications can include inflammation and ulceration of the colon with tissue death or perforation, which may result in peritonitis. People affected may develop anemia due to loss of blood.

Bacterial cellular morphologies

Bacteria and Archaea are classified by direct examination with the light microscope according to their morphology and arrangement.

Anilingus Stimulating the anus of another person by the use of one’s mouth

Anilingus is the oral and anal sex act in which a person stimulates the anus of another by using the mouth, including lips, tongue, or teeth. It is also called anal–oral contact and anal–oral sex, and is additionally known by slang names.

References

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