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| − | <big><big><center>[[WikiBlood|'''BACK TO WikiBlood''']]</center></big></big>
| + | ===Introduction=== |
| − | <br>
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| − | <big><center>[[Immunology - WikiBlood|'''BACK TO IMMUNOLOGY''']]</center></big>
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| − | ----
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| − | =Introduction= | |
| − | [[Image:Routes of Infection.jpg|thumb|right|150px|Routes of Infection - B. Catchpole, RVC 2008]]
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| − | Infection is a primary cause of disease. Three pathways of infection are identified: bacterial, viral, and parasitic. In all three cases, microorganisms can display similar characteristics. They can manifest as '''primary (obligate) pathogens''' or '''secondary (opportunistic) pathogens''', the former of which always corresponds to disease, and the latter of which depends on prerequisites being fulfilled before causing disease. As such, secondary pathogens can be found in healthy animals, but they lie in wait until a primary cause compromises the immune system and then manifest symptoms. Secondary pathogens can even masquerade as '''commensal''' organisms, or those which operate in harmony with the animal, until they become pathogenic.
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| − | Microorganisms can enter the body by three routes: '''contact''' (typically dermatological infection), '''aerosol''' (typically respiratory infection), or '''orofecal''' (typically enteric infection). Infection can be either '''exogenous''' (via entry to epithelial surfaces) or '''endogenous''' (intracellular, extracellular, or vesicular).
| + | One of the main causes of disease is infection by microorganisms, with four types so far identified: |
| | + | *[[Viruses]] |
| | + | *[[Bacteria]] |
| | + | *[[Fungi]] |
| | + | *[[Parasites]]- comprising [[protozoa]] and [[helminths]] |
| | | | |
| − | =[[Viruses - WikiBlood|Viruses]]=
| + | A fifth controversial type are Pirons, which are infectious proteins that are believed to be the cause of bovine spongiform encephalopathy (BSE) and the human variant Creutzfeldt–Jakob disease (vCJD).<br /> |
| − | [[Image:Virus structure.jpg|thumb|right|150px|Virus Structure - B. Catchpole, RVC 2008]]
| + | <br /> |
| − | ==Structure==
| + | All exist as either: |
| | + | *Primary pathogens ('''obligate'''): presence always corresponds with disease |
| | + | *Secondary ('''opportunistic'''): prerequisites must be fulfilled before disease occurs |
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| − | ==Replication==
| + | Microorganisms can enter the body by three routes: |
| − | ==Routes of infection==
| + | *'''Contact''': typically seen in dermatological infections |
| − | ==Prevention and control==
| + | *'''Aerosol''': typically respiratory infections |
| | + | *'''Orofecal''':typically enteric infections |
| | | | |
| − | *[[Vaccines - WikiBlood|Vaccines]]
| + | {{Learning |
| | + | |flashcards = [[Host Invasion by Microorganisms Flashcards|Host Invasion Flashcards]] |
| | + | }} |
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| − | =[[Bacteria - WikiBlood|Bacteria]]= | + | ===References=== |
| | + | *<div id="Janeway">{{citation|initiallast = Murphy|initialfirst = K|2last = Travers|2first = P|finallast = Walport|finalfirst = M|year = 2008|title = Janeway's Immunobiology|ed = 7th |city = New York|pub = Garland Science Publishing}}</div> |
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| − | ==Structure==
| + | *http://www.cellsalive.com |
| − | ==Replication==
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| − | ==Routes of infection==
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| − | ==Prevention and control==
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| | | | |
| − | =[[Parasites - WikiBlood|Parasites]]=
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| | + | {{review}} |
| | + | <br><br> |
| | + | {{Jim Bee 2007}} |
| | + | [[Category:Immunology]] |