Poxviridae Flashcards
What are the 2 subfamilies of family Poxviridae?
Chordopoxvirinae
Entopoxvirinae
Which genus of Poxviridae appears
ovoid in shape with long threadlike surface tubules arranged in a criss-cross pattern like a “ball of yarn”?
Genus Parapoxvirus
Poxviruses have ________ symmetry
with a dumbell shaped core and 2 lateral bodies
complex symmetry
What are the 2 important viral particles found in Poxviruses?
**EEV **(Extracellular Enveloped Virus)
and
**IMV **(Intracellular Mature Virus)
T/F:
Both EEV and IMV poxvirus particles are infectious
TRUE
Which viral particle of poxviruses is released by budding and has 2 membranes?
EEV
Which viral particle of poxviruses is released by cell lysis and has 1 membrane?
IMV
Describe the genome of Poxviruses
Linear DSDNA
The smallest genus of Poxviridae is
Parapoxvirus
The largest genus of *Poxviridae *is
Entomopoxvirus
What is special about how viruses in Poxviridae replicate?
Poxviridae is a DNA virus
that can replicate
in the cytoplasm
because they have evolved to encode enzymes for transcription and replication
Antigenic characteristics of Poxviridae include
NP nucleoprotein and genetic recombination within genus.
ONLY one genus of Poxviridae has antigenic hemagglutinin (HA)
which is it?
Orthopoxviruses
have HA
How does the **stability **of Poxviridae differ from other enveloped viruses?
Unlike other enveloped viruses, Poxviridae is
extremely stable in the environment
and can remain infectious for months, as well as survive for years in dried scabs
Which Poxvridae genus can be transmitted via the respiratory route?
Capripoxvirus (sheeppox)
*Poxviridae *is highly ___________, meaning it causes cutaneous skin lesions
epitheliotropic
Most genuses of family *Poxviridae *are host-specific
EXCEPT for genus ____________
Orthopoxvirus
infects many species
Describe the summary of skin lesions typically seen in Poxviruses
Macule → Papule → Vesicle → Pustule → Scab or Ulcer → Scar
What is the difference between a **macule **and a papule?
A macule is a flat red lesion of local inflammation,
A papule is a raised red lesion indicative of invasion of neighboring tissues
Which comes first, a vesicle or a pustule?
vesicle
If this bursts, an ulcer is formed
If a pustule ruptures, an ulcer is formed
otherwise, the pustule remains intact and a scab forms
Cowpox, Monkeypox, Smallpox, Camelpox, Ectromelia, Horsepox, Rabbitpox,
*Uasin Gishu Virus, Ectromelia virus, *and Vaccinia virus
are all virus species belonging to this genus
Genus Orthopoxvirus
T/F:
Cowpox, a species of Orthopoxvirus is COMMON in cows
FALSE!
*Cowpox *is UNCOMMON in cows!
________ is endemic in Europe and Asia only, while
_________ is confined mostly to remote villages in central and west Africa
Hint: Both are species of Orthopoxvirus
Cowpox is endemic to **Europe **and Asia
and
Monkeypox is found in remote villages of Africa
Rodents serve as a reservoir host in this virus endemic to Europe and Asia only
Cowpox
*Cowpox *mostly infects ______, Humans, and Zoo animals
Cats
A newly partruitioned cow had been seen hanging out with an orange farm cat.
After about 5 days, the cow started acting mildly febrile, and developed lesions on her teats. Her suckling calf then developed lesions in its mouth.
Later, it was noticed that this cow had a decreased milk yield.
What are your 5 DDx for these symptoms?
- Cowpox*
- Pseudocowpox*
- Bovine Herpesvirus*
- Vesicular stomatitis*
- Udder Impetigo *(bacterial dermatitis)
A newly partruitioned cow had been seen hanging out with an orange farm cat.
After about 5 days, the cow started acting mildly febrile, and developed lesions on her teats. Her suckling calf then developed lesions in its mouth.
Later, it was noticed that this cow had a decreased milk yield.
The farmer calls you back and you find out new information.
The cow is from eastern europe, and histology shows the HA hemagglutinin antigen. What is your definitive diagnosis?
Only Orthopoxviruses have the HA antigen, so this cow is suffering from
Cowpox
Your outdoor cat came in one day with a single lesion on his head.
After 8 days, several other lesions appeared and about 2 days after that,
the lesions turned into *discrete, circular and ulcerated papules *about 1 cm diameter.
After a while, you noticed he had a stuffy nose, or mild coryza and some conjunctivitis.
What is your diagnosis?
Can you get this virus from your cat? What symptoms should you look for in yourself?
Cowpox (Orthopoxvirus) infection via a rodent or arthropod bite from being outside
YES, this virus is zoonotic and symptoms you may experience are
- macropapular lesions on your hands and face*
- enlarged and painful local lymph nodes*
- fever, vomiting, and sore throat*
What virus should you be worried about if treating
monkeys in remote villages in central and west Africa**?
Monkeypox (Orthopoxvirus)
Genus Parapoxvirus includes what 3 species of viruses?
- Pseudocowpox*
- Contagious Ecthyma (ORF virus)*
- Bovine Papular Stomatitis Virus*
A newly partruitioned cow had been seen hanging out with an orange farm cat.
After about 5 days, the cow started acting mildly febrile, and developed lesions on her teats. Her suckling calf then developed lesions in its mouth.
Later, it was noticed that this cow had a decreased milk yield.
The farmer tells you that he is from Canada and is seeing “horse-shoe shaped ring lesions” on his cow where the scabs have dropped off. Histology has shown an ovoid shaped virus with a criss-cross pattern on its surface, much like a ball of yarn. What is your diagnosis?
Pseudocowpox species of virus of genus Parapoxvirus
T/F:
The term “Milker’s Nodules” refers to human infection by *Cowpox, *a species of genus Orthopoxvirus
FALSE!!
“Milker’s Nodules” refers to Pseudocowpox, a species of genus Parapoxvirus
- Contagious Ecthyma* is also known as
- Scabby mouth, Contagious pustular dematitis, and sore mouth*.
But what is it most commonly known as?
ORF!
(parapoxvirus)
A shepherd with a flock of new sheep has noticed that all of the baby lambs in his flock have these lesions in their mouths. Out of all the dams, only a few have started showing lesions in the commissures of their mouths, at the mucocutaneous junction and a few look like they have lesions on their teats. The shepherd is concerned because this virus seems to be spreading extremely rapidly.
What is your diagnosis? What may have caused this virus?
*Contagious Ecthyma *or ORF
Because it is a new flock, the shepherd probably used
instruments to dock and ear-tagging pliers that were contaminated.
A scab from the environment could have also caused it.
A shepherd with a flock of new sheep has noticed that all of the baby lambs in his flock have these lesions in their mouths. Out of all the dams, only a few have started showing lesions in the commissures of their mouths, at the mucocutaneous junction and a few look like they have lesions on their teats. The shepherd is concerned because this virus seems to be spreading extremely rapidly.
The shepherd is concerned about his friend’s flock in the neighboring town and asked if you would vaccinate his flock as well.
What will you tell this shepherd?
That **NO, you will NOT vaccinate his friend’s flock **because you
are not supposed to use in farms or flocks that do not already have problems with
ORF/ Contagious Ecthyma
A shepherd with a flock of new sheep has noticed that all of the baby lambs in his flock have these lesions in their mouths. Out of all the dams, only a few have started showing lesions in the commissures of their mouths, at the mucocutaneous junction and a few look like they have lesions on their teats. The shepherd is concerned because this virus seems to be spreading extremely rapidly.
How will you confirm with histology that this is ORF or Contagious Ecthyma?
Because ORF/ Contagious Ecthyma is a parapoxvirus,
the virus will look like a ball of yarn.
A shepherd with a flock of new sheep has noticed that all of the baby lambs in his flock have these lesions in their mouths. Out of all the dams, only a few have started showing lesions in the commissures of their mouths, at the mucocutaneous junction and a few look like they have lesions on their teats. The shepherd is concerned because this virus seems to be spreading extremely rapidly.
Should the shepherd be worried about contracting this from his sheep?
It is ORF/ Contagious Ecthyma
so YES, he should be worried and treated.
What are the 3 species of viruses classified as Genus Capripoxvirus**?
- Sheeppox*
- Goatpox*
- Lumpy Skin Disease of Cattle*
How do you tell the difference between *Sheeppox *and Goatpox using serology?
TRICK!
You can’t
Sheep and Goatpox are endemic to which regions?
Africa
Asia
Europe
A farmer in Africa with a mixed flock of non-native merino sheep and african local breed of sheep, has noticed that his favorite sheep Buttercup
is exhibiting signs of depression, salivation, watery eyes, and runny nose. Her eyes seem swollen. The local vet is out of town so it will take you 4 days to get there. After 4 days, almost 75% of the merino flock is exhbiting the same symptoms, and almost all the baby lambs have died. But amazingly, the local sheep seem unaffected. Buttercup is now showing lesions on her phaynx, larynx, and vagina, and these lesions are leaving a star-shaped scar.
What is your diagnosis?
Malignant form of sheeppox (Capripoxvirus)
A farmer in Africa with a mixed flock of non-native merino sheep and african local breed of sheep, has noticed that his favorite sheep Buttercup
is exhibiting signs of* depression, salivation, watery eyes, and runny nose*. Her eyes seem swollen. The local vet is out of town so it will take you 4 days to get there. After 4 days, almost 75% of the merino flock is exhbiting the same symptoms, and almost all the baby lambs have died. But amazingly, the local sheep seem unaffected. Buttercup is now showing lesions on her phaynx, larynx, and vagina, and these lesions are leaving a star-shaped scar.
What is the first thing you should do upon figuring out that this is Sheeppox?
REPORT IT IMMEDIATELY!
There is a flat, hemorrhagic form of _________ in some European Goats with a high case fatality rate
Goatpox
A herd of cattle in Iraq has been experiencing
fever, mutiple nodular lesions on their skin and mucous membranes, and have enlarged lymph nodes.
This virus is enzootic to subsaharan africa and the middle east.
What virus is causing these symptoms, and what is the protocol for treatment?
Lumpy Skin Disease (Capripoxvirus)
Unfortunately, you must slaughter all infected and in-contact cattle
:(
The owner of a piggery has noticed lesions on the abdomen and inner thighs of some of his younger pigs. A few pigs look a little greasy with exudative lesions.
One mother pig had piglets recently and all of her piglets now have lesions covering their entire body, including some lesions in the upper respiratory tract!
What is causing this virus, and what is the virus called?
Swinepox (Genus Suipoxvirus)
caused by
pig louse Hematopinus suis
This virus can occur in 3 different forms:
Dry (cutaneous) form
Diptheritic (wet) form
Ocular form
Fowlpox (Genus Avipoxvirus)
This is the first virus ever grown in embryonated eggs
Fowlpox (Avipoxvirus)
Which form of Avipoxvirus/Fowlpox
is the most common?
Cutaneous (DRY) form
Which form of Avipoxvirus/ Fowlpox
has the worst prognosis? How do these animals die?
Diptheritic (WET) form
Chickens die from asphyxiation when the lesions coalesce and form a necrotic pseudomembrane
How is Avipoxvirus/Fowlpox
controlled?
With vaccination with a modified live fowlpox
and by control the most common vector of transmission, mosquitoes
Which unclassified sheep virus has 2 clinical forms:
Lip and Leg Ulceration Form
Veneral Form- Balanoposthitis
Ulcerative Dermatosis of Sheep
Most poxviruses have this slightly basophilic characteristic intracytoplasmic inclusion body
Type B Guarnieri Inclusion Bodies
What type of intracytoplasmic, strongly eosinophilic inclusion bodies will you see
in the histology of Cowpox and Ectromelia virus?
Type A ATI
Inclusion Bodies
Avipoxviruses are the ONLY poxviruses with this
characteristic intracytoplasmic inclusion body
Bollinger and Borrel Bodies
You can diagnose most poxviruses using inoculation into an embryonated egg
(CAM) technique. Which poxvirus will not grow in the chicken embryo?
Parapoxviruses
(Pseudocowpox, Contagious Ecthyma/ORF, and Bovine Papular Stomatitis)
