In developing countries, formula is frequently prepared improperly, resulting in high infant mortality due to malnutrition and diseases such as diarrhea and pneumonia. This is due to lack of clean water, lack of sterile conditions, lack of refrigeration, illiteracy (so written instructions cannot be followed), poverty (diluting formula so that it lasts longer), and lack of education of mothers by formula distributors. These problems and resulting disease and death are a key factor in opposition to the marketing and distribution of infant formula in developing countries by numerous public health agencies and NGOs (discussed in more detail at Nestlé boycott and International Code of Marketing of Breast-milk Substitutes).