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
What type of virus can replicate in more than 1 host tissue/organ
Pantropic Virus
What are the 5 outcomes of viral injury?
- Cell Lysis
- Apoptosis - of host cell as last resort defense mechanism
- Oncoviruses
- Persistent Infection - virus remains dormant for long period of time
- Immunosupression - infect/destroy immune system specific cells
An Ulcer is an opening in the skin from the sloughing of necrotic tissue past the epidermis: True or False?
TRUE
A Nodule is a benign skin growth at the top layer of skin: True or False
FALSE: a nodule is a solid tumorous mass deep in the dermis
A wart is a benign growth on the top layer of the skin
What is the complement pathway activated by?
C1 binding to C-reactive protein on the pathogen surface
Allows C4 to attach and cleave into C4b and C4a parts
What is the C3 convertase and C5 convertase factors of the alternative pathway?
C3: C3b-Bb
C5: C3b-Bb-C3b
Which has the shorter lag phase, greater magnitude, and class-switched IgG, and IgG having been exposed for a long period of time? Primary or Secondary Humoral Immune Response?
Secondary Humoral Immune response
-in Primary: IgM doesn’t stay long
Humoral Immunity is a part of classical immunity: True or False
FALSE - it’s a part of adaptive immunity
What are the consequences of complement activation?
Lysis (MAC)
Opsonization (C3a)
Activation of inflammatory response (C3a + C5a)
Clearance of immune complexes (removal of particulate antigens)
Which immunoglobulin cleaves into 2 parts? Pepsin or Papin?
Pepsin; Papin cleaves into 3 parts
Define an epitope
An epitope is an antigen determinant
Define a Paratope
Part of the AB that recognizes antigen (small region of antibody FAB region)
Types include: Antibodies (Ab), BCR’s, and TCR’s
_________ & __________ recognize native protein antigens without processing or without MHC
BCR’s and Ab’s
MHC I is only on ___________, and MHC II is only on ___________ (B-cells, macrophages, and dendritic cells)
T-cells, Antigen Presenting Cells (APC)
MHC I is a part of the exogenous or endogenous antigen pathway?
Endogenous antigen pathways - Cytotoxic T Lymphocyte (CTL) recognizes complex of MHC I + peptide and kills infected cell
What activated macrophages for DTH response?
CD4 + TH1 which allows peptide boding to MHC II
What activated B-cells for Antibody Response?
CD4 + TH2
MHC II binds peptide
What types of cells serve as a bridge between innate and adaptive immunity, and activate naive T cells?
Dendritic Cells - stimulate adaptive immunity via the lymph nodes
What types of cells are associated with ADCC (Ab dependent cell-medicated cytotoxicity)?
NK cells
Macrophages
Neutrophils
Eosinophils
What type of cell responds to intestinal helminths?
Eosinophils
What is a disease caused by the invasion and multiplication of a living agent in/on a host?
An Infectious Disease
The invasion of an organism in/on a host (ticks, fleas, parasites)
Infestation
A disease transmissible from one human/animal to another via direct or airborne routes
A Contagious Disease
A disease caused by an agent capable of transmission by direct, airborne, or indirect routes form an infected person, animal, plant or contaminated inanimate reservior
A Communicable Disease
Latent Period
Microbe replicating but not enough for host to become infectious
Incubation period
Microbe replicating but not symptomatic
What is a reservoir?
A habitat where an infectious agent lives, grows, and multiples (humans, animal, or environment)
They maintain pathogen over time from year to year/ generation to generation
Pathogens can evade immunity for animals to become “susceptible again,” and re-infection can occur: True or False
TRUE
Define Balanced Pathogenicity
When pathogens can cause infections with minimal symptoms
All sick animals are reservoirs: True or False
FALSE
