What do exogenous sources of infection include?

* Airborne: These infections are spread through the air, often in the form of droplets or aerosols. Examples include influenza, measles, and tuberculosis.

* Droplet: These infections are spread through contact with respiratory droplets from an infected person. Examples include the common cold and strep throat.

* Contact: These infections are spread through direct contact with an infected person or object. Examples include skin infections, such as impetigo, and sexually transmitted infections (STIs), such as herpes and gonorrhea.

* Fomite: These infections are spread through contact with an object that has been contaminated with the infectious agent. Examples include doorknobs, countertops, and medical instruments.

* Animal: These infections are spread through contact with an infected animal. Examples include rabies, Lyme disease, and tularemia.

* Vector: These infections are spread by insects, such as mosquitoes, ticks, and fleas. Examples include malaria, yellow fever, and plague.