Fecal-oral infection route and prevention

The fecal-oral route is the pathway by which disease-causing organisms (pathogens) present in the faeces of an infected person or animal enter the mouth of another person and cause infection. The pathogens are bacteria, viruses, protozoa and worm eggs.

Diseases spread this way: diarrhoea, cholera, typhoid, dysentery, hepatitis A and E, polio, giardiasis, amoebiasis, roundworm and hookworm infection. Diarrhoeal diseases are still a major cause of child illness in Nepal, especially in the monsoon.

Transmission route (F-diagram)

Pathogens travel from faeces to a new host through five "F"s:

             +--> Fluids (water) ------+
             |                         |
             +--> Fingers (hands) -----+
 FAECES -----+                         +--> FOOD --> MOUTH
             +--> Flies ---------------+       (new host)
             |                         |
             +--> Fields (soil, crops)-+

1. Fluids – drinking water polluted by sewage, open defecation near sources or leaking pipes.
2. Fingers – unwashed hands after toilet use or cleaning a child.
3. Flies – flies sit on faeces, then on food.
4. Fields – open defecation and use of raw night soil on fields; vegetables and soil get contaminated; children play on soil.
5. Food – contaminated by any of the above, or by unclean utensils and poor cooking.

Preventive measures

Barriers are put at two levels:

Primary barriers (stop faeces reaching the environment)

• Safe excreta disposal: use of sanitary toilets (pit latrine, pour-flush, septic tank); end open defecation (Nepal declared itself Open Defecation Free in 2019).
• Safe disposal of children's faeces.
• Hand washing with soap after defecation.

Secondary barriers (stop pathogens reaching the mouth)

• Safe drinking water – protect sources, boil, filter, chlorinate (e.g. Piyush), or SODIS.
• Hand washing with soap before cooking and eating.
• Food hygiene – wash fruits and vegetables, cook properly, eat hot food, cover food, clean utensils.
• Fly control – cover food and toilets, manage solid waste, keep surroundings clean.
• Proper sewage and waste water treatment; separate water supply and sewer lines.

Other measures

• Health and hygiene education in schools and communities.
• Vaccination (polio, typhoid, hepatitis A, rotavirus).
• Oral rehydration solution (ORS) and zinc for treatment of diarrhoea to prevent deaths.
• Regular deworming of children.

Breaking the route at the source (toilets + hand washing + safe water) gives the largest health benefit.