Poxvirus & Ashfarvirade Flashcards
Do not worry about terms here
Which viruses belong to the Subfamily Chordopoxvirinae? What is the genus name?
Which viruses belong to the Subfamily Entomopoxviriae?
Myxoma virus affects which species?
Goat pox virus, Sheep pox virus, Lumpy skin disease virus; Capripoxvirus
Poxviruses of insects
Myxoma virus affects rabbits
Poxviridae has how many subfamilies? Genera? Species?
2, 22, 83
Viruses we will be focusing on are highlighted in red.
Edward Jenner was a pioneer in the field of vaccinology who discovered the
concept of the first ______ vaccine. He identified the ?
smallpox
dentified the link between the cow pox nodules in the udder
of cattle and the miler’s nodules
Label accordingly
Edward Jenner, smallpox
Members of the family ______ are the most complex viruses that infect
various species of vertebrates.
poxviridae
Small poxvirus have three first novel criteria:
1. The first disease to be ______.
2. The first virus to have some effective ______ therapy.
3. The first vaccine ______.
eradicated, antiviral, developed
Poxviruses grow on the CAM of the ECE and produce pock lesions
CAM = coroantmembrane?
ECE = embryonated chicken egg.
Poxviruses replicate in the _______ and produce _________ inclusion
bodies.
cytoplasm, intracytoplasmic
Poxviruses prefer to replicate and grow in the _______.
epidermis
Immune response against poxviruses last longer times (?).
8-10 years
WHO declared the eradication of human poxvirus?
1977
Why was smallpox given its name?
To distinguish it from largepox
What can be seen in these images?
Smallpox
Mummy of egyptian that have died from small pox.
Girl infected with small pox.
Smallpox virus
No animal ______
Two species
1. Variola major ( ____ % fatality)
2. Variola minor (__-___% fatality)
Smallpox has shaped _______
Earliest evidence: ______ ______
_______ ___ (_____ BC)
reservoir, 20, 1-2, civilization, Egyptian mummies, Ramses V, 1157
General properties of members of the family
Poxviridae
* _____ shape
* Among the ______ ___ virus (____- ____ nm) in diameter
* Complex symmetry consists of ( ____ and two _____ bodies)
* Enveloped within the _______ inclusion body
Brick, largest, DNA, 200, 300, core, lateral, cytoplasmic
EM of poxvirus
Very characteristic
Label accordingly
Went through labels of this image. Need to know structures.
Physicochemical properties of Poxviridae
* Virions tend to aggregate in _____ ____ solution
* Infectivity of some members of family poxviridae are resistant to _____ enzyme
* Some members of family poxviridae are insensitive to ____
* Virion infectivity is sensitive to common ______, _______, _____
agents
* Virion infectivity is sensitive to temperatures greater than ____
* Virions are relatively stable in ____ conditions at ____ temperature
* They can be _____ with little loss of ______
high salt, trypsin, ether, detergents, formaldehyde, oxidizing, 40°C, dry, room, lyophilized, infectivity
Biological properties of Poxviridae
* Host range may be ____ in ______ animals and in ____ culture
* Poxviruses infecting humans are _____ except for ?
* Neutralizing ______ and ___-mediated immunity play a major role in ______ of vertebrate poxvirus infections
* Reinfection rates are generally ___ and usually less ______
* People who are infected with small pox are generally immune to the disease for
?
broad, laboratory, tissue, zoonotic, molluscum contagiosum
virus (MOCV) and the orthopoxvirus variola virus (VARV) (the etiologic agent of
smallpox, now eradicated), antibodies, cell, clearance, low (hot is getting high immune titer of Ab so it can
neutralize upcoming infection), severe, the rest of their lives (solid immunity against reinfection).
Describe the pathogenesis of poxvirus
Target organ of poxvirus after circulating throughout body is?
The skin
Poxvirus
* Infection starts through ______ of the small poxvirus in the ______ respiratory tract
* Virus dissemination through the _____ and cell associated viremic spread
inhalation, upper, lymphatic
What are the Different stages of poxvirus
lesion
Painful
Redness
Vesicle –> swollen
ruptures
Scar/no scar
Pustules = participation of _______ bacteria. Bacteria invade ______ and form _____.
pathogenic, vesicle, pustule
Label accordingly
Large in size and genome is large as well.
Parvovirus
* Genome: single molecule of _____ _____ strand DNA (? kb)
* Genome encodes about ___ proteins about ___ of them contained in the virions
* Virus replicates in the _____ unlike other ___ viruses which replicate in the_____
* Nucleic acids constitute about
____ %of the particle weight
linear, double, 130-300, 200, 100, cytoplasm, DNA, nucleus, nucleus, 3
Poxvirus infection cycle
- Entry and release of core
(mechanism unknown).
2- Early mRNA synthesis products
release core, cause cell
proliferation, and local immune
suppression.
3- DNA synthesized for packaging
and as template for
intermediate gene expression –
products include transcription
specificity factors for late gene
expression.
4- Transcription and translation
of late (structural) protein
genes; particles assembled at
Golgi; particles released on cell
lysis or directly infect adjoining
cell
Mechanism of poxvirus release by exocytosis
______ virion (IV) formed from ____, not by _______.
IV matures to form? (IMV)
IMV acquires another membrane to form ? (IEV)
IEV transported to, fuses with ?
Immature, Golgi, budding, infectious intracellular mature virion, intracellular enveloped virion, plasma membrane
Ortho-poxvirus-Cow-poxvirus:
Characterized by ?
papular, pustular, and crusty exudative lesions on the
udder and adjacent areas of skin
Ortho-poxvirus-Cow-poxvirus: _____ serve as reservoir hosts of the virus, which also is contagious to?
Rodents,
humans, cats and maybe some other animals species
What can be seen in these images?
Ortho-poxvirus-Cow-poxvirus
Capripoxvirus- (Sheep and Goat pox)
The _____ ______ of all pox diseases of domestic animals
_____ and _____ of all ages may be affected
Generally more severe in ____ animals
High mortality in ____ animals and significant ______ loss
-decreased ___ production
-damage to the quality of _____ and _____
Transmission:
- ____contact is the main mode of transmission
-indirect by contaminated _____
Incubation period : __ to ____ days
- _______ ,
-increase in ______ rate,
-edema of the ____, and a _____ discharge from the nose
most important , Sheep, goats, young, young, economic, milk, hides, wool, direct, environment, 4, 8, hyperthermea, respiratory, eyelids, mucous
Capripoxvirus- Sheep and Goat pox
Affected sheep lose their ____ & stand with an ____ back
______ nodules develop, which may be distributed ____
over the body
Lesions: obvious in the areas of skin where the wool/hair ______, such as ?
Lesions usually scab and persist for ___-___ weeks, healing to leave
a permanent _______ scar
Lesions within the ?
Sheep and goat pox viruses do not appear to infect ____
Control based on sanitary _____ and ___ and _____ vaccine
appetite, arched, Cutaneous, widely, shortest, the head, neck, ears, axillae, and under the tail, 3-4, depressed, mouth affect the tongue, gums, and ulcerate, humans, prophylaxis, live, inactivated
Capripoxvirus-
Sheep and Goat poxvirus infection
Lumpy Skin Disease Virus (LSDV)
____ morbidity rate; ___: mortality rate
Losses
Endemic in ?
Transmission
-mechanical by ______ vector
-ingestion of ____ and ____ contaminated with infected ____
Clinical sings include: ?
Marked reduction in ____ yield in lactating cattle
____ nodules develop over the ____ body, particularly on the ? (__– ____) days after virus inoculation
High, Low, decreased milk production, abortion, infertility, loss of condition &
damaged hides, Africa and reported in the Middle East, arthropod, feed, water, saliva, pyrexia, rhinitis, conjunctivitis and excessive salivation, milk, Painful, entire, head, neck, udder, 7 , 19
LSDV
Pox lesions: mucous membranes of the ___ _____ tract, ____ and ____ –> resulting in primary and secondary _____
* Depression, anorexia and emaciation
* Pregnant cattle may ____, some are covered in ____
* Bulls may become ____ due to _____ and testicular atrophy
–> Diagnosis based on ?
–> Serological tests include ____ and _____.
mouth, alimentary, trachea, lungs, pneumonia, abort, nodules, infertile, orchitic, viral isolation, ELISA and PCR for detection of viral antigen, SNT, FAT
Transmission of LSDV
Biting of _____ is the main mode of viral
transmission
* Transmission increases during the ___ ____ and _____ seasons
* Calves drinking milk from the LSDV infected
cows
flies, wet
summer, autumn
What can be seen in this image?
LSDV
What can be seen in this image?
Lesions are Pathognomonic lesion
All superficial lymph nodes are enlarged.
LSD-clinical signs- Diagnosis
* Fever, anorexia, rhinitis, conjunctivitis, excess salivation
* Nasal discharge (thick to watery) fluid
* Infertile bulls due to orchitic (inflammation of testis)
* Mastitis: decreased milk production
* Lachrymation: infection of the eyes which may lead to blindness
* Poor conditions due to emaciation of the infected animals
Need to wear PPE to protect yourself, animal, and environment.
Nasal swabs, saliva
Surgical removal of nodules with scalpel
Economic impact of LSDV infection on affected animals
Emaciation = lose meat
LSD virus vaccines and control measures
* Attenuated Neethling strain vaccine produce protective immunity in animals
* All cattle should be vaccinated annually (once a year) before summer and the rain
seasons
* Calves borne to vaccinated cattle remain immune for up to 6 months, then should
be vaccinated again annually
protection for up to 6 months = maternal immunity
Dispose of carcasses in very deep holes with lime salt?/salt and then cover with soil
Parapoxvirus
Family
Genus
Parapoxvirus
Papules, vesicles, pustules
* Lips, nose, eyelids, mouth
* Very painful lesions
* Animals may recover
1-4 weeks after infection
Camel-poxvirus infection
Outbreaks reported in the ?
Closely related to -___ virus, the etiological agent for ____
Causes severe generalized disease in ____, with extensive ___ lesions
Enlarged _____ _____ and ___ lesions
Lesions appear ___-__ days after the ____ of fever, starting as ______ ________, developing into _______, _________, and ________ later turning into _______
Severe cases usually occur in ______ animals,
Case-fatality rate may be as high as ____%
Spreads by _____ contact and ____ via a contaminated _____
The virus appears to be infectious to ____
What vaccines are available?
Middle East, Africa, and Asia, variola, smallpox, camels, skin, lymph nodes, skin, 1-3, onset, erythematous
macules, papules, vesicles, pustules, crusts, young, 25, direct, indirect, environment, humans, Live attenuated vaccine and an inactivated vaccine are available?
What can be seen here?
Camel-poxvirus
What can be seen here?
Avipoxvirus- Fowl Poxvirus or Avian Poxvirus
Crust = late stage
Avipoxvirus- Fowl Poxvirus or Avian Poxvirus
Common in which species?
Decrease ___ production
High _____ rates
Forms?
commercial chickens, turkeys, other species of pet and wild birds
egg, mortality
Cutaneous lesions: nodular, wart-like proliferations of
hyperplastic epithelium involve the skin of head (comb,
wattles, corners of mouth, nostrils and eyes)
-Diphtheritic form: proliferative lesions on the mucous
membranes extend into the sinuses;
involvement of the larynx and trachea : dyspnea and rales
Fowl poxvirus necropsy and histopathological lesions
Fowl poxvirus necropsy and histopathological lesions
Swollen Keratinocytes with eosinophilic
intracytoplasmic inclusion bodies (H&E)
Swine Pox virus (SwPV)
* Only member of the genus ______ and there is
little _____ variability among strains
* SwPV can persist in the ______, even in ___
conditions.
* SwPV is susceptible to most common forms of ?
* _____ are the only natural hosts for SwPV. _____
are not affected
* SwPV is mechanically transmitted by the ?
* Classic pox disease is characterized by ?
* SwPV may be cultivated in a range of ___ cells in
vitro. ___________ and __________ are used to detect SwPV-Ag
* ____ is common diagnostic assay
* Recovered animals are _____ to reinfection
* Are there any vaccines on the market?
Suipoxvirus, genetic, environment, dry, disinfectants including acid treatment, alcohols,
aldehydes, alkalis, Swine, Humans
hog louse,
Hematopinus suis
formation of macules, followed by progression to papules,
vesicles, pustules, and crusts. Secondary bacterial
infections can also occur
host, Immunofluorescence,
immunohistochemistry, PCR, immune
Currently no available
vaccines against SwPV
Swine pox virus (SwPV)
Monkey-pox virus (MPXV)
* Family: _______
* Genus: ______
* Share antigenic relationship with _____ virus and _____ virus
* First identified by ? in
1958
* Animal reservoirs (4)
Poxviridae, Orthopoxvirus, smallpox, Vaccinia, Preben von Magnus
-Monkeys
-Gambian giant rat
-Prairie dogs
-African Squirrels
Monkeypox virus
Monkeypox virus reseroivrs
How does monkeypox virus spread?
________ _______ ________ ______
the necessity of a comprehensive global surveillance system for monitoring emerging
pathogens through more advanced approaches.
Monkeypox virus reverse zoonosis
Describe the monkey-pox virus disease progression
Describe the monkey-pox virus disease progression
Monkeypox virus- Prevention and control
No current treatment is available
* Smallpox vaccines (cidofoir, ST-246, and Vaccinia immune
globulin (VIG) can be used to control monkeypox virus outbreak
* JYNEOS vaccine used in the USA to control the smallpox virus
* Smallpox virus vaccine can protect against monkey poxvirus:
antigenic relationships (85% effective)
* MPXV vaccine is effective when administered before exposure
to the virus
* MPXV vaccine: can be given four days from the date of
exposure to prevent the onset of the diseases (not usual for other viruses; can not always do vaccination for viruses).
* MPXV vaccine: if given between 4-14 days of exposure: it
reduce the symptoms of the disease but may not prevent the
diseases
Poxvirus infection in Rabbits
Myxomatosis in rabbits
Myxomavirus causes localized benign fibromas in rabbits
* Blepharo-conjunctivitis and swelling of the muzzle and
ano-gential region giving the animal a leonine appearance
* Progression of the diseases in rabbits survive longer time
* Presence of subcutaneous gelatinous swellings all over the
body
* Most of the infected animal die within 2-3 days
Poxvirus infection in Rabbits
Myxomatosis in rabbits
Molluscum contagiosum
* Caused by a poxvirus (molluscum contagiosum virus)
* Usually a benign, mild skin disease characterized by lesions
(growths) that may appear anywhere on the body
* Within 6-12 months, Molluscum contagiosum typically
resolves without scarring but may take as long as four years
What can be seen in this image?
Molluscum contagiosum
How would you diagnose a patient with poxvirus?
- Case history
- Clinical signs
- PM lesions
- Laboratory diagnosis –> Proper sampling from affected organs
(vesicular fluid, scabs, skin lesions etc)
-Transportation of the specimen to the laboratory
-Detection of virus by microscope (light, EM)
-Histopathology examination (Intracyctoplasmic inclusion bodies) - Detection of virus Ag by (AGPT, SNT etc)
-Detection of viral Abs (ELISA, FAT, etc)
-Detection of viral nucleic acid (PCR-Real time PCR
What is one way you can isolate poxvirus?
-Isolation of pox virus on ECE (Pock lesion on CAM)
How can you detect poxvirus via microscope?
Light, EM
What would you see histologically when examining poxvirus?
-Histopathology examination (Intracyctoplasmic inclusion bodies)
What tests would you use to detect poxviruses via Antigens? Antibodies?
AGPT, SNT
ELISA, FAT
What test would you use to detect poxviruses by viral nucleic acids?
Real time PCR, PCR
What can be seen in this image?
Guarneri Bodies - Small pox
What can be seen in these images?
Describe the vaccines used for Smallpox control.
Today’s vaccine is live attenuated
vaccinia virus
Vaccinia’s genome looks
similar to cowpox, but it is not identical.
The World Health Organization
(WHO) Intensified Smallpox
Eradication program began in?
1967
Smallpox was declared eradicated in?
1980 (last case in 1977
List the common antiviral therapies for poxvirus and there respective mode of action.
What are the synonyms of Asfarviridae?
-Pesti Porcine Africaine
-Peste Porcina Africana
-Maladie de Montgomery
The Asfarviridae virion has multiple layers of ____, ____ envelope, ____, and _____ envelope.
core, internal, capsid, external
Describe the genome of Asfarviridae.
Linear ds-DNA (170-194) kbp with complementary terminal loops
Where do viruses within the family Adfarviridae replicate?
They replicate in the cytoplasm
How do viruses within the family Asfarviridae perform transcription and mRNA processing?
uses virus-encoded enzymes
Describe the host range of viruses within the family Asfarviridae.
Domestic pigs, wild boar
How is Asfarviridae classified?
Single species in the single genus Asfarvirus
Describe the morphology and structure of Asfarvirdae viruses.
- Enveloped virus
- Icosahedral in outlines * Approximately 200 nm in diameter
- Genome
-Single molecule ds-DNA -Genome size: 170-190 Kb -Genome have covalently closed ends
Label this image accordingly.
Label this image accordingly.
Label this image accordingly.
Label this image accordingly.
Label this image accordingly.
What can be seen in this image?
Evolution of African swine fever across the world from Jan-Sep 2018
Domestic swine (circles) Wild boar (triangles)
Within the family Asfarviridae, there is a huge variation in the viral ______.
virulence
Highly virulent viruses within the family Asfarviridae have a ?
high mortality rate 10-100% in
7-10 days post infection
Moderately virulent viruses within the family Asfarviridae cause?
Acute viral infections in
pigs with high survival rates
among affected animal
Low virulent viruses within the family Asfarviridae cause?
cause seroconversion among
affected animals
Describe the African swine fever virus ASFV infectious cycle.
- Virus enter cells through the clathrin-
mediated endocytosis - Virus progress rapidly through the
endocytic pathway - Replication and assembly occur in
cytoplasm - New progeny viruses exit the cells
through budding
African swine fever virus (ASFV) infectious cycle
African swine fever virus (ASFV) infectious cycle
Describe the transmission cycle of ASFV
The sylvatic cycle of ASFV is defined as
enzootic or sylvatic transmission cycle: is a portion of the
natural transmission cycle of a pathogen.
Sylvatic refers to the ?
occurrence of a subject in or affecting wild animals.
Sylvatic cycle is also known as ?
also enzootic or sylvatic transmission cycle
The Trans-stadial transmission is ?
A sequential passage of parasites acquired during one life
stage
The Trans-ovarial transmission is ?
(transmission from parent to offspring via the ovaries)
Describe the tick-borne transmission of ASFV
Transmission is dynamic between animals.
Describe the transmission of ASFV via direct contact.
List the ASFV-immune strategies.
Describe the clinical and field examination based diagnosis of ASFV.
- Marked hyperemia of the legs
- Bloody mucoid foamy nasal discharges
- Large demarcated zone of hyperemia in the perineal region
- Necrotic exudate is sloughing from the lesion
What can be seen in these images?
ASFV
What can be found upon necropsy in an ASFV- infected pig?
- Per-acute and acute infection
- Three classic lesions for the ASFV
-Large dark friable spleen
-Large hemorrhagic gastro-hepatic LNs
-Large hemorrhagic renal LNs - Renal petechial, serosal hemorrhages
- Sub-endocardial hemorrhage
What can be seen here?
ASFV
Large dark friable spleen
What can be seen here?
ASFV
-Large hemorrhagic renal LNs
* Renal petechial, serosal hemorrhages
What can be seen here?
ASFV
Large hemorrhagic gastro-hepatic LNs
* Renal petechial, serosal hemorrhages
What can be seen here?
ASFV
Sub-endocardial hemorrhage
What can be seen here?
ASFV
Sub-endocardial hemorrhage
How would you diagnose ASFV?
History
Clinical signs
Necropsy Findings
Virus isolation on cell culture
What samples would you collect to diagnose, identify, and isolate ASFV?
from live animals: swabs (nasal, rectal, oropharyngeal etc)
from freshly dead or slaughtered: tissues (kidney, liver, spleen, lymph nodes)
When diagnosing, identifying, and isolating ASFV, _______ of virus in cell culture is one of the definitive
diagnostic approaches.
Hemadsorption
What other diagnostic methods could you use to diagnose, isolate, and identify ASFV?
Virus antigen detection: * Direct fluorescent antibody test (DFAT
* Detection of the viral nucleic acids
-Conventional PCR assays
-Real-time PCR technique using specific probes
* Detection of viral antibodies in sera of animals: ELISA
* Seroconversion
What is the primary ASFV control strategy?
Primary control strategy (Establishment of control area around the
infected animal premises).
-Avoid the contact between the infected and susceptible animals
-Quarantine and movement restrictions of animals with good biosecurity measures
-Infected zone: 3 Km -Buffer zone: 2 Km ->5 Km: surveillance zone
What is the primary ASFV eradication strategy?
Depopulation of the feral pigs around the infected premises
_______ strategies based on ____ vaccines and ______ proteins have also been
explored to control and eradicate ASFV.
Vaccination, DNA, recombinant
Why have scientists failed to develop an ASFV vaccine?
The complexity of the virus particle and the ability of the virus to modulate host
immune responses are most likely the reason for vaccination failure
ASFV - Vaccine
ASFV - Zones, Areas, and Premises Designations for Domestic Swine
Different zones needed to minimize spread of virus
ASFV - Zones, Areas, and Premises Designations for Feral Swine
Describe.
- The minimum infected zone is 3 Km * Pigs found nearby on the nearby landscape the infected Zone will be adjusted to
incorporate all pigs * Zone adjustment to include all pigs which can potentially results in lager infected zone
The viral family Irdoviridae are ____ viruses generally ___-____nm diameter
DNA, 120, 200
Describe the Iridoviridae virion
Icosahedral symmetry, virus core, outer capsid separated by an internal lipid membrane
Describe the Iridoviridae genome
single linear ds-DNA ranges (140 to 300 kbp) in size
List the give genera of Irdoviridae
Iridovirus, Chloriridovirus, Ranavirus, Megalocytivirus, Lymphocystivirus
Sixth group of intraerythrocytic viruses of fish & reptiles that appear distinct
Icosahedral shape
Red Sea bream iridovirus:
Family: ________ Genus: ________
Iridoviridae, Megalocytiviru
Describe the Red Sea bream iridovirus’ duration of infection in hosts, distribution, and form of transmission.
Long-term persistence in hosts, following
acute or inapparent infections. Worldwide
distribution. Horizontal transmission.
Red Sea bream iridovirus mortality rate is?
100% in captive fish populations
What are the clinical signs of Red Sea bream iridovirus infection?
anemia, branchial hemorrhages,
enlarged spleen, “cytomegalic” cells
(macrophages) with cytoplasmic inclusions:
spleen, kidney, intestine, eye, pancreas,
liver, heart, gill, brain, intestine.
What can be seen in this image?
Red Sea bream iridovirus
Enlarged spleen
What can be seen in this image?
Cytomegalic cells
What can be seen in this image?
Lymphocystis in a walleye
What can be seen in this image?
Histological appearance of lymphocystis, depicting cellular hypertrophy
Frog virus 3 - widespread disease epizootics amongst ___ _______ populations in ?
wild amphibian, North America, Europe, and Asia
Which amphibians are the most susceptible to Frog virus 3?
- Tadpoles (most susceptible) and frogs.
Frog virus 3 infection results in?
Localized cutaneous hemorrhage and ulceration or more severe systemic disease with edema, hemorrhage, and necrosis in
numerous organs.
Describe the mortality rate of Ambystoma tigrinum virus?
mortality in larval and adult salamanders in western North America from late summer to early autumn. o mortality up to 90% in 7-14 day
What does Ambystoma tigrinum viral infection result in?
Necrosis and hemorrhage in many organs
What factors contribute to the spread of Ambystoma tigrinum virus?
Environmental temp plays important role: infection at 18C results in death, whereas infection at 26C leads to survival
Santee-Cooper ranavirus contributes to substantial seasonal loss of _____ ______ __________ ____ in lakes in the United State
wild adult largemouth bass
The Santee-Cooper ranavirus affects what parts of the body?
Internal tissues, including the swim bladder, which becomes reddened and enlarged and contains a yellow
exudate.
In cases of Santee-Cooper ranavirus, involvement of the swim bladder results in?
moribund fish that float to the surface
What can be seen in this image?
Effusion under the skin into the body.
What can be seen in this image?
Ulceration
-Vaccines_______.
a. damage host cells b. are only needed once c. kill viruses d. stimulate an immune response
Enteroviruses differ from neurotropic viruses mainly in their:
a. Type of nucleic acid b. Size c. Capsid shape d. Ability to survive acidic conditions
How can you detect a virus by microscope?
Light, EM
