Virology Flashcards
(109 cards)
1
Q
What is virology?
A
the study of viruses and viral disease
2
Q
What is a virologist?
A
someone who studies viruses
3
Q
T or F: Viruses cause high rates of morality and morbidity in animals and birds?
A
True
4
Q
T or F: Viruses cause financial loss to livestock and poultry industries
A
True
5
Q
T or F: Some viruses are zoonotic ?
A
True
6
Q
Are viruses non living?
A
yes
7
Q
What does a viruses contain?
A
nucleic aicd genome (DNA or RNA) surrounded by a protein coat (capsid) and in some cases a lipid envelope
8
Q
T or F: Viruses posses standard cellular organelles?
A
False, THEY DONT
9
Q
Can viruses make energy or proteins by themsleves?
A
no
10
Q
T or F: Viruses are obligate intracellular parasites?
A
true, they hack the cell machinery
11
Q
Do viruses have the capability to multiply by division?
A
No
12
Q
How does a viruses reproduce?
A
by an assembly line in which various parts come together from different parts of the host cell to form new virus particles
13
Q
What is a capsid?
A
protein shell of a virus that encases/envelopes the viral nucleic acid or genome
14
Q
What is a capsid made up of?
A
capsomeres held together by non covalent bonds
15
Q
What is nucleocapsid?
A
capsid + virus nucleic acid
16
Q
T or F: some viruses have additional layer known as envelope
A
True
17
Q
What is a envelope of a viruses made up of?
A
lipid bilayer derived from host cell
18
Q
T or F: Glycoproteins are present on the surface of the envelope, and often appear as spikes
A
True
19
Q
T or F: Naked viruses have only protein capsid enclosing nucleic acid?
A
true
20
Q
T or F: Enveloped viruses have an additional lipid layer enclosing the protein capsid enclosing nucleic acid?
A
True
21
Q
What is pleomorphism?
A
the ability of some viruses to alter their shape of size
22
Q
Does RNA have double-stranded and single stranded RNA
A
yes
23
Q
Does DNA have double-stranded and single stranded DNA
A
Yes
24
Q
What is virus replication?
A
attachment, penetration, uncoating, release in large numbers, assembly and maturation and synthesis of viral nucleic acid and protein
25
How are viruses classified?
the international committee on taxonomy of viruses
26
How are virsues transmitted?
direct contact, indirect, and common vehicle transmission
27
What is common vehicle transmission?
food borne or feces borne
28
What is vertical transmission?
infection that is transferred from mother to embryo, newborn
29
How does one diagnose viruses?
gross evaluation and histopathology
30
How do you detect viruses?
cultivation and isolation on tissue culture or inoculation in eggs
31
What is serology of viruses?
ELISA, viral antigen to host antibody, florescent antibody staining and immunohistochemical staining
32
What is RT-PCR
Reverse transcription polymerase chain reaction
33
How does one treat viral infections?
antiviral drugs, immune system stimulation
34
How does one prevent viral infections?
vaccinations, live attenuated, non-replicating, recombinant DNA, disinfectants and hygiene
35
What is an all in, all out management system?
animal houses are emptied, cleaned and disinfected between batches of animals
36
What is culling?
killing of animals to control viruses spread
37
What is pathogenicity?
the ability of a virus to cause disease in a host
38
What is pathogenesis?
manner of development of a disease
39
What is avirulent?
not harmful to the host
40
T or F: virulence is not an absolute property, but depends on many variables
True
41
What are factors related to a virus?
genetic variation, route of entry in host, affinity to host, dose of infection, immuno evasion
42
What are factors related to the host?
host species, host immunity, host physiological factors, fever
43
What are some other factors of virulence?
environment and dual infections
44
How does one measure a virus?
lethal dose 50: the dose of a virus required to cause death to 50% of animals
45
What is a route of entry for a virus?
skin, transcutaneous injection, mucous membranes, gastrointestinal tract, respiratory tract
46
What is viremia?
presence of virus in the blood
47
How does a virus spread into the bloodstream?
subepitheial tissue/ lymphatics and direct injection
48
What is secondary viremia?
virus has replicated in major organs and once more entered into circulation
49
What is a disseminated infection?
spreads beyond the primary site of infection
50
What is a systemic infection?
number of organs and tissues are infected
51
How does a viruses spread via nerves?
peripheral nerves, through receptor neurons, blood brain barrier
52
What is a nuerotropic virus?
viruses that can infect neural cells
53
What is tropism?
a affinity of a virus for a particular host tissue
54
What is a pantropic virus?
can replicate in more than one host organ/tissue
55
What is virus-cell interactions?
inhibition of host/cell nucleic acid or transcription
inhibition of protein synthesis
toxic viral infections
interference with cellular membrane function
56
T or F: cell lysis following virus replication allows release of new viruses?
True
57
What is apoptosis?
process of programmed cell death, cell suicide
58
What is an oncovirus?
causes cancer
59
What is a persistent infection of a virus?
not immediate death of a host cell, remain latent in host cell for long periods
60
T or F: Viruses cause immunosupression?
True
61
T or F: Shedding of infectious virons is crucial to the maintenance of infection in populations?
True
62
T or F: acute infections is intensive shedding over short periods of time?
True
63
T or F: persistent infections can shed at lower titers for months to years?
True
64
What are warts?
benign skin growths that appear when a virus infects the top layer of the skin
65
What is erythema?
reddening of the skin
66
What does a virus in the respiratory tract cause?
inflammation
obstruction of air passages
hypoxia and respiratory distress
67
What does a virus in the central nervous system cause?
bursting (lytic) infections of neurons
neuronal necrosis
killing of phagocytic cells
inflammatory cels around blood vessels
68
What is progressive demyelination?
canine distemper, damaged nerve, scarred myelin
69
What does damage to endothelium cause?
hemorrhages
70
What is an teratogenic viruses?
cause developmental defects of embryo or fetus in utero infections
71
What is the latent period of infectious disease?
microbe is replicating but not yet enough for the host to be infectious
72
What is the incubation period of infectious disease?
microbe is replicating but host has no symptoms
73
What is communicable disease?
disease caused by agent capable of transmission by direct, airborne or indirect routes from infected person, animal or plant
74
What is a reservoir?
habitat in which infectious agent lives and grows
75
T or F: pathogens can escape immunity so that animals become susceptible again?
True
76
T or F: pathogens can evade immunity, allowing reinfection to occur after a short period of time
True
77
T or F: all sick animals are reservoirs?
False
78
What is vertical transmission of pathogens?
from host to its offspring, possibility through placenta or during parturition
79
What is horizontal transmission of pathogens?
from reservoir to new host
| direct and indirect
80
What is a vehicle for pathogens?
inanimate object which serves to communicate disease
81
What is a vector?
a living organism that serves to communicate disease
82
What are fomites?
object that can be contaminated and transmit disease on a limited scale
83
What is a mechanical vector?
agent does not multiply or undergo part of its life cycle while in vector
84
What is a biological vector?
agent undergoes changes in vector
85
What are determinants of emergence?
type of agent
host susceptibility
pathogenetic distance
contact frequency
86
What is pathogenic adaption?
increased antibiotic resistance
| increased virulence
87
What factors increase transmission of a pathogen?
increasing abundance of host
increasing pathogen prevalence
increasing contact
88
What is prevention of infectious disease?
inhibiting the introduction or establishment of a disease into an area, herd or individual
89
T or F: Rinderpest is only animal disease that has been eradicated?
True
90
What does eradication of a infectious disease involve?
complete elimination of the pathogen from a defined region
91
What is primary prevention?
avoid occurrence of disease by health promotion or specific protection
92
What is secondary prevention?
primary prevention failed
minimize damage
early diagnosis
93
What is tertiary prevention?
both primary and secondary failed
| rehab
94
What is farm biosecurity?
external ( leaving) and internal (spread)
| all measures taken to minimize the risk of introduction and spread of agent
95
What is the purchasing policy?
closed herd system
reduce number of new animals
vaccination and health status of new animals
quarantine new animals
96
How does one remove infected individuals from a herd?
testing and slaughter
97
What is mass therapy?
eliminate pathogen from herd
98
What is biological control of an infection?
introducing a predator
99
What is the difference between isolation and quarantine?
isolation is ill with disease
| quarantine is exposed to disease
100
What is chemoprophlaxis?
use of antimicrobal drugs
| prevent infection
101
What are the four W's of immunization?
Where
When
Who
Why
102
What are features of a safe vaccine?
```
safe to use
effective against different strains
few side effects
low in cost
benefit outwieghs risk
```
103
Where does the World Animal health publication come from?
world organization for animal health OIE
104
What are sentinel labs?
direct contact with patients
105
What is infected premises?
confirmed positive cases
| infected zone surrounds this
106
What is contact premises?
may have been exposed to infection
107
What is a buffer zone?
surrounds infected zone
108
What is one health?
healthy people, healthy environment, healthy animals
109
How to protect livestock from wildlife?
separate livestock from wildlife
vector control
wildlife population control
