What is a pathogen? A zoonotic pathogen?
Author of Response: Rick Koelsch, Livestock Environmental Engineer, University of Nebraska, firstname.lastname@example.org
Response: A pathogen is a biological agent that causes disease or illness. Zoonotic pathogen refers to pathogens naturally transmitted between animals and humans. There are several pathways whereby pathogens can invade humans. The principal pathways are via breathing air, drinking water, eating contaminated food, or hand to mouth contact.
The human body has many natural defenses against the more common pathogens in the form of the human immune system and through the presence of "helpful" bacteria in the body. However, if the immune system or "good" bacteria are damaged in any way or unprepared for a pathogen, then the pathogen can proliferate and cause harm.