The CDC report on Preventing Diarrheal Disease in Developing Countries highlights five effective household water treatment methods to reduce waterborne illnesses, which cause millions of deaths annually. These methods include ceramic filtration, solar disinfection (SODIS), flocculant/disinfectant powder (PUR), household chlorination, and slow sand filtration. Each method varies in effectiveness, cost, and ease of use, with benefits such as pathogen removal, affordability, and scalability, but also challenges like maintenance, recontamination risks, and user acceptance. The report emphasizes the importance of safe water storage and education to maximize health benefits.