Types of Pathogens

Communicable diseases are diseases caused by pathogens.Pathogens are microorganisms that cause disease and include bacteria, fungi, viruses and protoctists.Communicable diseases can be spread from one individual to another. They can also spread between species either directly or indirectly.Vectors are substances or organisms that carry diseases from one individual to another. For example insects spread many diseases while other diseases may be spread by food or water.