Host Foreign Species - Infection
An infection is the in short the hosting of foreign species in a
host organism. There is a war that is involved between the host
and the foreign body as the infection organism is looking to use
the hosts resources in order to multiply. All of this occurs at
the expense of the host. If the host and the intruder could
coexist there would be no problem, but this isn't the case. The
infecting organism in it's intrusion will interfer with the
normal operation of the host, and in many cases inflict with the
survival of the host. These organisms are usually consired to be
tiny and microscopic, however the definition is in fact much
wider than that.
Pathogens are a broad group that include: (Infectious Disease is
the specific branch of medicine that focuses on these infections
and pathogens.) - Parasites - Bacteria - Viruses - Prions -
Viroids - Fungi
All organisms with multiple cells(multicellular) are colonized
to some extent by an extrinsic organisms. The large majority of
these exist in either a relationship with the host like
mentioned above. The difference between an infection
and a colonization is due to the circumstance which exists
as a result of the former. Basically if the colonization of the
external body comprises the life of the host organisms it is an
infection.
Several variables are involved which determine the intruders
outcome on the host: - The Route of entry - The access to host
regions that it gains - The amount or load of the initial
inoculant - The intrinsic virulence of the particular organism -
The status of the immune system of the host that is being
colonized