Waterborne diseases are caused by microorganisms such as bacteria, viruses, and parasites that are transmitted through contaminated water sources. These diseases are a significant public health concern, particularly in areas with limited access to clean water and poor sanitation practices.

According to the World Health Organization (WHO), waterborne diseases account for approximately 21% of all communicable diseases globally. This percentage indicates the proportion of diseases that can be directly attributed to the consumption or use of contaminated water.

Here's a breakdown of the key points:

1. Waterborne Diseases: Waterborne diseases are caused by pathogens that contaminate water sources. These pathogens can enter the body through various routes, including drinking water, bathing or swimming in contaminated water, or consuming food that has been prepared with contaminated water.

2. Types of Waterborne Diseases: Waterborne diseases include diarrhea, cholera, typhoid, hepatitis A, giardiasis, cryptosporidiosis, and many others. These diseases can cause severe illness, leading to dehydration, malnutrition, and even death if left untreated.

3. Global Impact: Waterborne diseases have a significant impact on global health. They are responsible for millions of illnesses and deaths each year, with children being the most vulnerable population. Lack of access to clean water and poor sanitation practices contribute to the spread of these diseases.

4. Importance of Clean Water and Sanitation: Ensuring access to clean water and promoting proper sanitation practices are crucial in preventing waterborne diseases. This includes treating drinking water, improving water infrastructure, promoting hand hygiene, and implementing proper waste management systems.

5. Other Modes of Transmission: While waterborne transmission is a significant route for many diseases, it is important to note that not all communicable diseases are waterborne. Other modes of transmission include person-to-person contact, airborne transmission, vector-borne transmission (through insects), and foodborne transmission.

In conclusion, waterborne diseases account for approximately 21% of all communicable diseases worldwide. This highlights the importance of clean water and sanitation in preventing the spread of these diseases and improving public health.