Cleanliness in the community (sanitation), cleanliness in the home, and personal cleanliness are all important to prevent these sicknesses by stopping the spread of germs.
For example:
A man infected with parasites has diarrhea outside.
A pig eats the man’s stool.
One of the man’s children plays with the pig and gets stool on himself.
Later, the child starts to cry and his mother comforts him and cleans his fingers with her skirt. She also gets stool on her hands.
The busy mother prepares food for the family without washing her hands first. She uses her skirt to keep from burning her hands, forgetting that it was not clean.
The family eats the food. Soon everyone has diarrhea.
If the family had used any of these precautions, the spread of illness could have been prevented:
if the man had used a latrine or toilet.
if the pig had not been allowed to run free.
if the mother had not used her skirt to wipe the child’s hands and then touch the food.
if the mother had washed her hands after touching her child and before preparing food.
Sources
Burns, A. A., Niemann, S., Lovich, R., Maxwell, J., & Shapiro, K. (2014). Where women have no doctor: A health guide for women. Hesperian Foundation.