Diarrheal disease remains one of the world’s major public-health problems. WHO estimates that nearly 1.7 billion cases of childhood diarrheal disease occur every year, and approximately 443,832 children under the age of five die from diarrhea each year. Diarrheal disease is particularly serious in low- and middle-income countries, where access to safe drinking water, sanitation, and hygiene remains a challenge.

Unsafe drinking water is an important source of diarrheal disease. In 2022, at least 1.7 billion people worldwide were using a drinking-water source contaminated with feaces. Microbial contamination of drinking water can transmit diseases including diarrhea, cholera, dysentery, typhoid, and polio.

Improving access to safe drinking water, adequate sanitation, and good hygiene can substantially reduce the risk of diarrheal disease. Important preventive measures include using safe drinking water, washing hands with soap, maintaining good food hygiene, and using appropriate sanitation.

Household water treatment can also be an important public-health intervention, particularly for people who rely on contaminated or unreliable water supplies. Treatment methods can include filtration, boiling, chlorination, and other technologies designed to reduce microbial contamination. WHO continues to evaluate household water-treatment technologies for their ability to remove or inactivate pathogens.

Safe drinking water is therefore not simply a matter of taste or convenience. Where drinking water is contaminated or unreliable, improving water safety can play an important role in preventing disease, particularly among young children.

作者：Michael Chiu，MWS，CI
Previously published in Ming Pao Daily News – Updated and Revised in 2026