(RNA VIRUSES) Lesson 13: Picornaviridae Flashcards
(84 cards)
1
Q
General description of Picornaviridae
A
- very small (22-30 nm)
- Non-enveloped, positive-sense, single- stranded RNA viruses with icosahedral
symmetry - Replicate in cytoplasm
- Resistant to many organic solvents
- The capsid is composed of 60 protein subunits
- Each subunit consists of four proteins VP1
(1D), VP2 (1B), VP3 (1C) and VP4 (1A)
2
Q
Pico means
A
very small
3
Q
The capsid of Picornaviridae is composed of how many protein subunits?
A
60 protein subunits
4
Q
Each subunit of Picornaviridae consists of four proteins.
ENUMERATE
A
VP1 (1D)
VP2 (1B)
VP3 (1C)
VP4 (1A)
5
Q
This protein is located on the inner surface of the capsid.
A
protein VP4
6
Q
The protein VP4 location
A
inner surface of the capsid
7
Q
Picornaviridae replicate in
A
cytoplasm
8
Q
A number of genera of Picornaviridae that contain
viruses of veterinary significance
A
(CATTEE) 6
Cardiovirus
Aphthovirus
Teschovirus
Tremovirus
Erbovirus
Enterovirus
9
Q
belongs to the genus Aphthovirus
A
Foot-and-mouth disease virus
10
Q
Foot-and-mouth disease virus belongs to what genus
A
Aphthovirus
11
Q
it cause swine vesicular
disease
A
Enteroviruses
12
Q
Enteroviruses causes what disease
A
swine vesicular disease
13
Q
cause Teschen/Talfan disease, reproductive problems and
enteritis in pigs
A
Teschoviruses
14
Q
reproductive problems and
enteritis in pig
A
Teschen/Talfan disease
15
Q
Teschoviruses causes what disease
A
Teschen/Talfan disease
16
Q
cause encephalomyocarditis in young pigs
A
Cardioviruses
17
Q
Cardioviruses cause this disease in young pigs
A
encephalomyocarditis
18
Q
causes encephalomyelitis in chickens
A
Avian encephalomyelitis virus
19
Q
How many serotypes does Foot-and-mouth disease virus have
A
7
20
Q
viruses that cause OIE-listed diseases
A
Foot-and-mouth disease virus
Swine vesicular disease virus
Duck hepatitis A virus
21
Q
is a highly contagious disease of even-toed ungulates, characterized by fever and the formation of vesicles
A
Foot-and-mouth disease (FMD)
22
Q
Foot-and-mouth disease (FMD) is a highly contagious disease of even-toed ungulates, characterized by
A
fever and the formation of vesicles
23
Q
Foot-and-mouth disease (FMD) is a highly contagious disease of what animals
A
even-toed ungulates
24
Q
Seven major serotypes of Foot-and-mouth disease
A
- FMDV-A
- FMDV-Asia 1
- FMDV-O
- FMDV-C
- FMDV Southern African Territories (SAT) 1
- FMDV-SAT 2
- FMDV-SAT 3
25
T or F
No cross-immunity between different serotype but only within each serotype
TRUE
26
Large amounts of (FMD) virus are shed by infected animals in
all secretions and excretions
27
Virus shedding of FMD begins during this period
incubation period
28
Virus shedding of FMD begins during the incubation period, usually beginning about 24 hours before the appearance of clinical signs, and infectivity of animals is much reduced by
___________ days after
the lesions develop.
4-5 days
29
Infected groups of animals, particularly pigs, shed large quantities of virus in
exhaled air as an aerosol
29
Transmission of FMD occurs by
(a) direct contact (animal products including meat, offal, milk, semen and embryos)
(b) by the airborne route
(c) by mechanical carriage by people
(d) vehicles and fomites
29
T or F
Under suitable conditions of low temperature, high humidity and
moderate winds such aerosols may spread the virus over long
distances (within 10 km)
TRUE
30
most susceptible to infection because of their large
respiratory volume and the low infective dose required
Cattle
31
Why does cattle are most susceptible to infection
(a) respiratory volume
(b) low infective dose required
32
The virus is moderately resistant but is sensitive to pH outside the range 6.0 to 9.0.
FMD
33
FMD virus is moderately resistant but is sensitive to pH outside the range of ________
6.0 - 9.0
34
FMD virus can remain infective on soil for ______ days in the summer and for _______ days in the winter.
3
28
35
Following death and rigor mortis, the production of lactic acid in muscle inactivates the pH-labile virus but virus may persist in here
offal and bone marrow
36
Following death and rigor mortis, the production of _______ in muscle inactivates the pH-labile virus but virus may persist in offal and bone marrow
lactic acid
37
Following death and rigor mortis, the production of lactic acid in muscle inactivates this virus but virus may persist in offal and bone marrow.
pH-labile virus
38
Foot-and-mouth disease virus can persist in this region of animals that have recovered from FMD or in vaccinated animals following contact with live virus.
pharyngeal region
39
Persistence of FMD virus can last up to ________ in cattle, _______ in sheep and up to ________ in African Cape buffalo
three years
several months
five years
40
Persistence of FMD virus can last up to three years in cattle, several months in sheep and up to five years in this animal
African Cape buffalo
41
The principal route of FMD virus infection is by
inhalation
42
The principal route of FMD virus infection is by inhalation, although infection can also occur by
(IIIC)
ingestion
insemination
inoculation
contact with abraded skin
43
Following inhalation viral replication of FMD virus occurs in here
pharynx
44
Following inhalation viral replication occurs in the pharynx followed by spread to the _________ and distribution to predilection sites including the epithelium of the mouth, muzzle, feet and teats.
bloodstream
45
Following inhalation viral replication occurs in the pharynx followed by spread to the bloodstream and distribution to predilection sites including the ff:
epithelium of the mouth, muzzle, feet. and teats
46
FMD vesicle formation results from swelling and rupture of infected keratinocytes in the __________ at these sites.
stratified squamous epithelium
47
Following an incubation period of two to eight days, infected
cattle demonstrate the ff signs
(a) fever
(b) loss of appetite
(c) marked drop in milk production
48
There is profuse salivation as this appear in the mouth and rapidly rupture leaving raw, painful ulcers. It also appear
in the interdigital cleft and on the coronary band giving rise to lameness and the shifting of weight from one foot to another. It may appear on the teats and udder of lactating cows.
Vesicles
49
There is profuse salivation as this appear in the _______ and rapidly rupture leaving raw, painful ulcers.
mouth
50
Vesicles also appear in the _________ and _________ giving rise to lameness and the shifting of weight from one foot to another. It may appear on the teats and udder of lactating cows.
interdigital cleft and on the coronary band
51
Vesicles also appear in the interdigital cleft and on the coronary band giving rise to
_________ and _________.
lameness and the shifting of weight from one foot to another
52
Vesicles may appear on the ___________ of lactating cows.
teats and udder
53
The lesions of FMD heal rapidly but may become secondarily infected giving rise to the following conditions.
mastitis and underrunning of the sole
54
Infected animals show a marked loss in condition and growth rate but mortality
FMD
55
FMD: Death may occur in calves due to?
acute myocarditis
56
FMD: Although the virus does not cross the placenta, _______ may occur, probably as a result of the fever.
abortion
57
The disease is mild and characterized
by fever and vesiculation of the skin and mucous membranes.
FMD
58
Diagnosis of FMD
ELISA, RT-PCR, virus demonstrations from cell culture
59
How to Control FMD
vaccinations
affected and in-contact animals are
slaughtered
60
Following an outbreak of FMD, movement restrictions are
applied and infected premises must be thoroughly cleaned and
disinfected.
61
effective disinfectants for FMD virus
**Mild acids**such as citric acid and acetic acid
**Alkalis**
such as sodium carbonate
62
a mild vesicular disease of pigs which occurs sporadically in parts of
Europe and Asia
Swine Vesicular Disease (SVD)
63
Geographical distribution of Swine Vesicular Disease (SVD)
Europe and Asia
64
it is clinically indistinguishable from foot-and-mouth disease
Swine Vesicular Disease (SVD)
65
Swine vesicular disease virus is under this genus
enterovirus
66
The natural host is pig but is zoonotic (mild infection in man)
Swine Vesicular Disease (SVD)
67
Transmission of SVD
direct or indirect contact
68
the virus is
stable for long periods in the presence of organic matter in the
environment
Swine Vesicular Disease (SVD)
69
The spread of Swine Vesicular Disease (SVD) from farm to farm is dependent on the
movement of infected pigs or contaminated materials.
70
SVD
The ________ of infected pigs contain large quantities of virus.
tissues
71
The
infectivity of the virus is retained despite the pH changes that occur
during rigor mortis and the virus can persist indefinitely in
refrigerated pork
SVD
72
The incubation period of SVD
2-7 days
73
Subclinical disease is common
SVD
74
SVD virus entry
damaged skin or
ingestion
75
SVD
During the two- to three-day viraemia many organs
and tissues become infected.
76
Shedding of SVD virus can start before clinical signs are
evident and is heaviest in this week following
infection.
first week
77
The faeces and lesion material of infected pigs may
contain infective virus for many weeks or months
78
The clinical disease is characterized by a transient fever
followed by the development of vesicular lesions on the
feet, particularly on the coronary band, and less
commonly on the lips, tongue and snout. Lameness, dullness and inappetence occur but are not constant
signs.
SVD
79
SVD: The animals do not lose condition and the lesions heal
rapidly over the course of a few weeks.
80
The severity of the clinical signs of FVD is influenced by what?
strain of SVDV
route and dose of infection
husbandry conditions
81
Diagnosis for SVD
1. serological test (ELISA)
2. cell culture to demonstrate
cytopathic effect (CPE)
3. VNT
4. RT-PCR
82
Control for SVD
Bio-security, vaccines
