An infectious diseases is scientifically proven disease caused by microbes that are pathogens (called as pathogenic microbial agents). These are of multiple types.
- Pathogenic bacteria, causes diseases such as plague, anthrax and tuberculosis
- Protozoa,causing diseases like malaria, toxoplasmosis and sleeping sickness
- Fungi, causes infections like ringworm, candidiasis or toxoplasmosis
- Pathogenic viruses cause diseases like influenza, yellow fever or AIDS, which are basically not living organisms and are not microorganisms
These agents can cause diseases in animals or plants or both. These are usually qualified as communicable diseases ( also called contageous diseases) as they have the capabilities of transmission from one person to many others.
This transmission can happen in multiple ways. Air, physical contact, food, blood transfusion, body fluids or through contaminated objectsBird flu is an infection caused by avian (bird) influenza (flu) viruses. Theses flu viruses occur naturally among birds.
Dengue fever is a flu kind of illness spread by mosquito bites. Dengue and dengue hemorrhagic fever are caused by any of the dengue family virus.
Swine influenza (also called H1N1 flu, swine flu, hog flu, and pig flu) is an infection by any one of several types of swine influenza virus.