What is meant by communicable diseases? Describe the pathogenicity, clinical manifestation and prevention of cholera. (UPSC 2024, 15 Marks, )

संचारी रोगों का क्या अर्थ है? हैजा की रोगजनकता, नैदानिक अभिव्यक्ति और रोकथाम का वर्णन करें। (What is meant by communicable diseases? Describe the pathogenicity, clinical manifestation and prevention of cholera.)