CBSE Class 9 Answered

Means of spread of infectious diseases:

• Through air: The disease spread through sneezing or coughing through water droplets. E.g. common cold, tuberculosis.
• Through water: It can spread through consuming contaminated water, open defecation etc. E.g.- Cholera, Typhoid.
• Sexual contact: Diseases spread through sexual contact or the exchange of body fluids. E.g. - Syphilis, AIDS.
• Through vectors: Animals like flies and mosquitoes carry infecting agent from sick person to a healthy person. E.g.-Rabies, Malaria