Pathogen
Short description
A pathogen is a biological agent that can cause disease in a host. These include, for example, certain bacteria, viruses, fungi, and parasites.
Detailed description
Pathogens possess characteristics that enable them to infect a host and cause disease. Whether an infection actually leads to disease depends on the pathogen, the host, and other factors. Among other things, there is a distinction between obligate and facultative pathogens. Obligate pathogens can cause disease even in healthy people. Facultative pathogens primarily cause disease under certain conditions, such as a weakened immune system or exposure to normally sterile areas of the body.
