I want to know the answer to the following question:
What has had major effects on the transmission of diarrheal diseases?
All the background I'm provided with is that "Hand washing in developing countries, however, is compromised by poverty as acknowledged by the CDC: "Handwashing is integral to disease prevention in all parts of the world; however, access to soap and water is limited in a number of less developed countries.". Is that enough to answer the question?