Topic 64 - Rinderpest, peste des petitis ruminants (RED) Flashcards
Common name for Rinderpest
Cattle plague
Occurence of Rinderpest:
1st disease that has been succesfully eradicated
since June 2011
Causative agent of Rinderpest:
Rinderpest virus
Official name: Rinderpest morbiliivirus
How many serotypes does Rinderpest have?
None.
Rinderpest virus is uniformH
How many genotypes does Rinderpest virus have?
3.
they are related according to geographical origin
1. West African
2. East African
3. Asian
Resistance of Rinderpest virus
Low
enveloped virus
Can Rinderpest virus be inactivated?
Yes, in meat
Why can Rinderpest virus be incativated in meat?
The acidic pH in fermentation of the meat will inactivate the virus
What are the hosts of Rinderpest virus?
Main host = cattle.
But the virus can colonise and cause disease in
- Swine
- Other ruminants
Maintaining host of Rinderpest virus:
Cattle
Shedding of Rinderpest virus:
Excretes: mainly faeces, but also in saliva and urine
The virus is shed also during incubation
Transmission of Rinderpest virus:
By direct contact of herds, per os - Markets, drinking water
Can also be transmitted in frozen meat, the lymph nodes carrying the virus
Morbidity and mortality of Rinderpest virus:
Morbidity = close to 100%
Mortality = 40-90%
Mortality depends on if the breed is local or imported
Imported - close to 100%
Local - 40-50%
Pathogenesis of Rinderpest virus:
- Infection per os, but can also be inhaled
- There is a primary replication in the lymph nodes around the throath
- There is a viraemia, transporting the virus to other organs - Spleen, bone marrow, lymph nodes, mucous membrane
- There is an inflammation of the mucous membrane, we can also see necrosis and erosions.
What can we see in case of an animal surviving the Rinderpest virus, regarding immunity?
Lifelong immunity
It will also result in sterile healing
What is a sterile healing, in case of Rinderpest virus?
The virus is cleared from the infected animal, we have a maximum 3 week long carrying of the virus, but never longer
Incubation time for rinderpest:
3-9 days
Clinical signs. Name the different forms for Rinderpest virus:
- Acute form
- Peracute form
- Subacute form
We differentiate between 3 phases for all 3 forms of clinical signs, name them:
- Febrile phase = happens parallell with the viraemia
- Erosive phase
- Diarrhoetic phase
Clinical signs, acute form of Rinderpest virus
Febrile phase
High fever
Depression
Clinical signs, acute form of Rinderpest virus
Erosive phase
Erosions and necrosis of mucous membranes of the oral and nasal cavity
Clinical signs, acute form of Rinderpest virus
Diarrhoetic phase
Intensive diarrhoea
We can see epithelial tissue debris due to the mucous membrane necrosis.
We also get dehydration, and due to this we also see death
Clinical signs, peracute form of Rinderpest virus
Typicall seen in new-born animals, young calves and imported animals.
We see:
Fever
Death within 2-3 days
Because there is a death within short amount of time, the clinical signs are not always clear
Clinical signs, subacute form of Rinderpest virus
Mild fever
Serous nasal discharge
Lachrymation and salivation due to the necrosis of the mucous membrane
Clinical signsin sheep, goat and swine in case of Rinderpest virus
They are not as susceptible as cattle, so we see milder clinical signs:
Post mortem lesions for Rinderpest virus:
Most important ones are seen on the mucous membranes !!
- Necrosis and erosions, and due to the erosions the blood vessels are coming to the surface and we see fibrinous pseudo-membranes
- Necrosis + hyperaemia causes blackening of the folds of the large intestines, also called zebra stripes
- We see necrosis in the lymph nodes and payers patches
Histopathological lesions in case of Rinderpest virus:
- Necrosis of lymphoid and epithelial tissues
- Cytoplasmic inclusions bodies
- Syncytia = merging the cells
How can we diagnose Rinderpest virus:
We look at the epidemiology, clinical signs and pathology.
We also test for antigen and antibodies
Which test are done for detecting of antigens, in case of Rinderpest virus?
PCR !!
But can also use: virus isolation
Which test are done for detecting of antibodies, in case of Rinderpest virus?
ELISA
But also: virus neutralisation
In case of Rinderpest virus, what does presence of antibodies indicate?
Presence of the virus, becuse there is no vaccination
Differential diagnosis of Rinderpest virus:
Every disease with erosions !!
- Malignant catharall fever - Very hard to differentiate
- FMD
- Swine dysentry
Is Rinderpest virus a notifable disease?
yes
How was Rinderpest virus successfully eradicated, name some factors:
- The virus have low resistance
- There is only one mainting host species - cattle
- There are no long-carriers for the virus
- Sterile recovery
Prevention measures in case there is an outbreak of Rinderpest virus:
- Closed herds
- Stamping out
- There is a vaccine in stock, but this is only to be used in case of an outbreak !!
When was the last reported outbreak of Rinderpest virus?
2001
What is Peste Des Petitis Ruminants disease?
A disease that is very similar to the rinderpest, but caused by a independent virus
Occurence of Peste Des Petitis Ruminants:
Originally in Africa, but later spread to Asia and as of 2023 - Bulgaria
Causative agent of Peste Des Petitis Ruminants:
PPR virus
Peste Des Petitis Ruminants virus
How many serotypes for Peste Des Petitis Ruminants:
1
making the vaccination easier
Host range for Peste Des Petitis Ruminants:
Mainly: sheep and goat
But also susceptible: Indian buffalo, gazelle and cattle
What is special with cattle in case of Peste Des Petitis Ruminants?
They are seropositive, there are rarely any clinical signs.
And they do not carry the disease
How is Peste Des Petitis Ruminants transmitted?
by direct contact, through inhalation or per os
How is Peste Des Petitis Ruminants shed?
By excretes: saliva, urine, faces
Is there a season it is more common to see Peste Des Petitis Ruminants?
Yes.
During rainy season and in dry, cold weather
Morbidity and mortality of Peste Des Petitis Ruminants:
Morbidity: 90-100%
Mortality: 50-100%
**Mortality depends on the breed, ⭡imported or ⭣local
Pathogenesis of Peste Des Petitis Ruminants:
Same as rinderpest !!
- Infection per os, but can also be inhaled
- There is a primary replication in the lymph nodes around the throath
- There is a viraemia, transporting the virus to other organs - Spleen, bone marrow, lymph nodes, mucous membrane
- There is an inflammation of the mucous membrane, we can also see necrosis and erosions.
Incubation time for Peste Des Petitis Ruminants:
4-6 days
Clinical signs, acute form of Peste Des Petitis Ruminants:
Fever, due to necrosis and viraemia
Nasal discharge
Conjunctivitis which causes ⭡lacrimation
Necrosis of oral epithelium
Salivation
Erosions of the mucous membrane
Abortion
Clinical signs, peracute form of Peste Des Petitis Ruminants
Mostly in goats
Fever
Depression
Death
Clinical signs, chronic form of Peste Des Petitis Ruminants:
Mostly seen in sheeps
Milder clinical signs
Pathological lesions in case of Peste Des Petitis Ruminants:
In oral and nasal cavity:
1. Necrosis or mucous membranes
2. Sometimes haemorrhages
Gut:
1. Haemorrhagic enteritis
2. Necrosis
3. Zebra stripes
Lung:
1. Interstitial pneumonia
But this is only if the animal survives for a longer period of time, mostly in sheep (chronic form)
How can we diagnose Peste Des Petitis Ruminants?
Epidemiology
Clinical signs
Pathological lesions
Antigen detection
Antibody detection
How can we detect antigens?
PCR !!
But also: virus isolation
How can we detect antibodies?
ELISA !!
If there is a presence of antibodies in an endemic area, it does NOT support the diagnosis. In this case we have to do the paired test - repeating the test after 2-3 weeks and compare the level of antibodies
Differential diagnosis of Peste Des Petitis Ruminants:
Rinderpest
Bluetongue
FMD
Prevention of Peste Des Petitis Ruminants:
Depends on the area, if it is a endemic or free area.
Prevention of Peste Des Petitis Ruminants in an endemic area:
- Closed herds
- Movement restrictions
- Vaccination, attenuated - Gives good protection
Vaccination is done at the same as the other measures
In an Peste Des Petitis Ruminants endemic area, how often do we vaccinate?
1st: After 3 months of age (due to maternal protection
2nd: After 3 years
The vaccine have long protection - 3 tears
Prevention of Peste Des Petitis Ruminants in a disease free area:
- Prevention of introduction
- Monitoring of the virus in areas close the endemic areas
Measures in case there is an outbreak in a Peste Des Petitis Ruminants free area:
- Closed herds
- Stamping out
- Vaccine - BUT: needs special permission to use it within the EU