Exam 2 Flashcards
Types of Virus Transmission
Direct Indirect Common vehicle transmission (fecal contamination of water/food; virus contamination of meat) Airborne Vector (arthropod) Zoonotic Vertical
Impact of virus replication on host
- Cell Death
- No change
- Malignancy
- Fusion of cells (agglutination)
What is the first line of indication of a virus?
Clinical Signs
What are the types of detection of virus infection?
- Clinical Signs
- Necropsy
- Histopathology
Define Pleomorphism
The ability of a virus to change shape and size
What are the 6 steps of virus Replication?
- Attachment
- Penetration
- Uncoating
- Synthesis of virus nucleic acid/ genome
- Assembly and maturation
- Release in large numbers
A capsid is made up of many ___________, held together by _________________
Capsomeres, non-covalent bonds
All viruses are considered _________________
Obligate Intracellular Parasites
What are 3 types of treatments for viruses?
- Antiviral drugs
- Immune System Stimulation - interferons (proteins w/antiviral effects and modulate function of immune system)
- Synthesize Ab’s or administration of natural antiserum (Ab’s)
What are the types of Serology detection/diagnosis of viruses?
ELISA (enzyme linked immunosorbant assay)
Fluorescent Ab stain
Immunohistochemical stain
What are the 5 methods of prevention and control?
- Vaccination
- Proper hygiene and sanitation
- Elimination of arthropod vectors - biological and chemical control
- Quarantine
- Culling (killing) - burn or bury
What are the broad routes of entry of a virus INTO a host?
- Skin
- Mucous-membrane
- GI Tract
- Respiratory Tract
How can a virus enter a host through the skin?
A. From a cut/breach in the skin B. Transcutaneous Injection via: Bite of Arthropod Bite of Infected Animal Contaminated Objects (i.e. Needles)
How can a virus enter a host via a Mucous Membrane?
Through the : Conjunctiva (eye)
Oropharynx (mouth)
Genitourinary Tract/ Rectum
Define Viremia and the two types of viremia
Viremia - the presence of virus in blood
Primary - spread virus from subepithelial tissue/lymphatics
Secondary - directly injected in blood, through mosquito bite/syringes
Define Nuerotropic Virus
- Infects neural cells - caused by neural or hematogenus spread
- virus has an affinity for CVS
Define a Neuroinvasive Virus
Virus enters CVS after infection at peripheral sites
Define Neurovirulent Virus
Severe damage to the CVS
-virus causes disease to nervous tissue, leads to neurological symptoms and often death
What cell type to viruses use to cross the Blood Brain Barrier
Monocytes
What is the term for the specificity/affinity of a virus for a particular host tissue?
Tropism