Disease Transmission

Lesson learned: Two key actions isolate fecal material and prevent it from reaching the environment and the four F’s:

  1. Adequately disposing of adult and child feces and
  2. Handwashing with soap after using a toilet or cleaning a child after defecation.

Some respiratory tract infections, including influenza H1N1 and the SARS-causing coronavirus, are also transmitted in part by the hands. Proper handwashing with soap is an effective preventative measure against these infections as well.


  1. Feces are the source of diarrheal pathogens, microscopic “bugs”.
  2. If not disposed of safely, these bugs enter the environment and are then spread by the four Fs: flies, fingers, fluids, and surfaces such as fields. Blocking these routes of transmission is critical to the prevention of diarrheal disease. Which of the many possible hygiene practices would eliminate the most diseases?
  3. Boiling or disinfecting water in the home would reduce diarrhea, but preventing fecal pathogens from ever reaching household water is likely better and more cost-effective. Similarly, while foods should be reheated carefully to kill bugs that have multiplied during storage, preventing fecal pathogens from ever reaching food is more effective.
  4. Failure to do so results in new diarrheal infections.