Pathogenesis and control of vira disease Flashcards
What are the 4 cellular responses to infection?
no effect, cytopathology, hyperplasia, cancer
(blank) are nuclear or cytoplasmic aggregates of stainable substances, usually viral proteins
inclusion bodies
Many viral infections are (blank)
subclinical
T or F
the same disease may be produced by a variety of viruses
T
T or F
the same disease may produce a variety of diseases
T
T or F
the disease produced bears no relationship to viral morphology
T
pathology is determined by what 3 factors?
viral factors
host factors
family genetics
What is the study of origin and development of disease?
pathogenesis
(blank) are events during infection that results in disease manifestation in the host
disease pathogenesis
A strain of virus is more (blank) than another strain if it commonly produces a more severe disease
virulent
What are the steps of viral pathogenesis?
viral entry into the host primary site of viral replication viral spread cellular injury host immune response viral clearance or persistent infection viral shedding
Is this a characteristic of local or systemic viral infections:
site of pathology is at portal of entry?
local
Is this a characteristic of local or systemic viral infections:
site of pathology is at distant site?
systemic
Is this a characteristic of local or systemic viral infections:
incubation period is relatively long?
systemic
Is this a characteristic of local or systemic viral infections:
incubation period is relatively short?
local
Is this a characteristic of local or systemic viral infections:
viremia is absent
local
Is this a characteristic of local or systemic viral infections:
viremia is present
distant
Is this a characteristic of local or systemic viral infections:
duration of immunity is variable (may be short)
local
Is this a characteristic of local or systemic viral infections: Duration of immunity is usually lifelong.
distant
Is this a characteristic of local or systemic viral infections:
role of secretory IgA in resistance is usually NOT important
distant
Is this a characteristic of local or systemic viral infections: role of secretory IgA in resistance is usually important
local
What are the ways that viruses attach and enter cells?
skin
respiratory tract
GI tract
urogenital tract
after primary site of entry, the virus may spread within the host. What is the most common route?
blood or lymphatics
What do you call presence of virus in the blood?
viremia
T or F
viruses may be free in the blood?
T
They may be free in the blood or associated with a specific cell type
What 2 viruses have neuronal spread?
HSV
rabies virus
viruses tend to exhibit organ and cell specificities, this is called (blank)
tropism
What does tropism determine?
the pattern of system illness produced
tissue and cell tropism relates to the presence of cell surface receptors that the viral (blank) bind to initiate entry
VAP (glycoproteins)
Why might a virus not produce viral proteins in a host cell?
due to lack of cellular transcription factor
the outcome of viral infections reflects the interplay between (blank and blank)
viral and host factors
The induction of (blank) is among the major immune response
interferons
(blank and blank) are activated and respond to sites of viral infection
mononuclear cells
lymphocytes
Virus infected cells may be lysed by (blank) resulting from recognition of viral polypeptides on the cell surface
CTLs
(blank) directed against capsid or glycoproteins blocks the viral infection of cells.
neutralizing antibody
(blank) protects against infection by viruses through the respiratory or GI tracts (mucosal immunity)
secretory IgA antibody
What are IFNs?
host encoded proteins that are part of the cytokine family that inhibit viral replication
How soon do you get production of interferons (IFNs)?
within hours of viral replication
Interferons are essential to the (blank) antiviral immune response
innate
(blank) is critical for immunity against viral, some bacterial and protozoal infections
IFN gamma or type II interferon
(blank) is an important activator of macrophages and induces (bank) molecule expression
IFN gamma
MHC
(blank) secrete 1000 times more IFN than a similiarly induced fibroblast.
dendritic cells
cells must be (blank) to produce IFNs
induced
Infection with virus is a strong (blank) of IFNs
inducer
Single stranded RNA viruses is a (weaker/stronger) inducer of INF than DNA viruses
stronger
Can you induce IFNs via double stranded RNA an bacterial endotoxins?
yes
When are IFNs detectable and then what happens once they are?
soon after viral infection
viral production decreases
(blank) does not appear in response to viral infection until days following infection.
antibody