If waste materials contaminate the source of drinking water, the disease that is most likely to spread is Typhoid. Typhoid is caused by the bacteria Salmonella typhi, which is commonly found in fecal matter. When waste materials pollute the water source, they can introduce this bacteria into the water, making it unsafe to drink. Consuming contaminated water can lead to the spread of typhoid, resulting in symptoms such as fever, headache, stomach pain, and diarrhea.

It is important to note that the other options mentioned in the question, namely Scurvy, Malaria, and Anaemia, are not directly related to the contamination of drinking water by waste materials. Scurvy is a Vitamin C deficiency, Malaria is transmitted through mosquito bites, and Anaemia is a condition characterized by a deficiency of red blood cells or hemoglobin. Therefore, the correct answer is option 2: Typhoid.