The Plagues: Notifiable Ruminant Diseases Flashcards
what are the notifiable plagues of ruminants
sheep pox and goat pox
contagious bovine pleuropneumonia
rinderpest
peste des petits ruminants (PPR)
foot and mouth disease
what is the virus of sheep and goat pox
capripox
where is sheep and goat pox distributed
north africa
asia
southern europe
mediterranean basin
what is the incubation period of sheep and goat pox
4-7d
what is the morbidity and mortality of sheep and goat pox
Mortality:
10-80% (naive, sudden death)
Morbidity:
10-100% (naive)
is there a vaccine for sheep and goat pox
yes live attenuated <2 years immunity
what are the clinical signs of sheep and goat pox
Fever
Oculo-nasal discharge
Cutaneous pox lesions
Scabs
Oral lesions
Death
what are the post mortem lesions of sheep and goat pox
Typical pox lesions
“Sitfasts”
Visceral pocks in lung (liver, kidney)
Secondary pneumonia
how is sheep and goat pox transmitted
Direct — aersols from early clinical cases (ulcerated oral papules)
Abrasions
Indirect:
Fodder, bedding, wool, fomites, insects
No carriers
what are the key epidemiological features of the plagues or contgions
Disease free areas — agent intrusion
Sporadic epidemics: high morbidity +/- high mortality
- Imported diseased animal
- Smuggling infected live animals or animal products
- Loss of border controls (war, strife, civil breakdown)
- Nomads (traditional) (drought, flooding, strife)
- Carrier animals
- Wild animals
Mechanical spread
- Fomites
- insects
- animals
- Birds
- Aerosol spread
Establishment of infection in new areas:
- Failure of control procedures
- Poverty
- New strain of agent
what type of disease does contagious bovine pleuropneumonia (CBPP) cause
slowly progressive, often fatal, proliferative interstitial pneumonia of cattle caused by mycoplasma mycoides mycoides
what causes contagious bovine pleuropneumonia (CBPP)
mycoplasma mycoides mycoides
where is contagious bovine pleuropneumonia (CBPP) distributed
sub sarahan africa
what species does contagious bovine pleuropneumonia (CBPP) affect
cattle (buffalo)
what is the incubation period of contagious bovine pleuropneumonia (CBPP)
3-6 weeks
occ 6 months
what is the morbidity and mortality of contagious bovine pleuropneumonia (CBPP)
morbidity <90% in susceptible herds
mortality 50% of clinical cases
what are the clinical signs in adults of contagious bovine pleuropneumonia (CBPP)
Proliferative interstitial pneumonia
Hyper-acute
- Death by asphyxiation
Acute
- Pyrexia
- Coughing
- Respiratory distress
- Thoracic pain — arched back, head stretched forward
- Death
Chronic
- Slowly progressive pneumonia signs
what are the clinical signs of contagious bovine pleuropneumonia (CBPP) in calves
Polyarthritis not pneumonia
what are the post mortem findings of contagious bovine pleuropneumonia (CBPP)
Usually one lung affected
Interstitial pneumonia, lung ‘hepatisation’
- Pathologic alteration of lung tissue such that it resembles liver tissue
Pleurisy, thoracic edema <30 liters
Sequestrum
how is contagious bovine pleuropneumonia (CBPP) transmitted
Excretion early in disease
Direct
- Aersols
- Droplets
Indirect
- Urine, placental fluids
Sequestrum breakdown (stress, immunosuppression) <2 years
is there a vaccine for CBPP
yes
6 month immunity
injection rxns
what causes rinderpest (cattle plague)
morbillivirus
where is rinderpest distributed
last reported in east africa, pakistan
oct 2010 it was eradicated
what species does rinderpest affect
Cattle, buffalo, even-toed ungulates, pigs
how is rinderpest transmitted
By direct contact with a sick animal or its excretions (10 days)
Possibly indirect though meat (rare)
is there a rinderpest vaccine
yes
very effective
what is the incubation period of rinderpest
3-15 days
what are the clinical signs of rinderpest
Oculo-nasal discharge (‘weeping cattle’)
Erosion and necrosis of buccal mucosa
Foetid breath, dysentery
Rapid wasting, death
what is the mortality and morbidity of rinderpest
Mortality:
<100%
Morbidity:
<100%
what are PM lesions in rinderpest
Erosions in mouth, nasal cavity, esophagus
Intestinal hemorrhages ‘zebra striped colon’
what is the cause of peste des petit-ruminants (PPR)
morbillivirus
where is peste des petit-ruminants (PPR) distributed
africa
middle east
s india
asia
what are the species affected by peste des petit-ruminants (PPR)
goats and sheep
what are the clinical signs of peste des petit-ruminants (PPR)
Sudden death to chronic disease
Oculo-nasal discharge
Oral erosions
Hair stands erect
Enteritis
Broncho-pneumonia
Panting
Diarrhea
Death
Chronic
- Recurring erosions
- Intermittent fever
- Catarrh & diarrhea (sheep in Africa, goats in India)
how is peste des petit-ruminants (PPR) transmitted
direct contact with a sick animal or its excretions
what is the mortality and morbidity of peste des petit-ruminants (PPR)
Mortality:
<100%
Morbidity:
<100%
what are the PM findings of PPR
Dehydrated carcass
Necrotic stomatitis
Purulent pneumonia
Zebra stripes in colon
is there a vaccine for PPR
yes attenutated live or modified in cell culture
why is PPR eradication a possibility
One serotype
No carrier state
No sustainable wildlife reservoir
Effective diagnostic tools
Effective vaccines
what causes foot and mouth disease
Picornavirdae
Aphthovirus
what does foot and mouth disease affect
all cloven hoofed animals
where is foot and mouth disease endemic
africa
asia
middle east
south america
how many serotypes are there of foot and mouth disease and is there cross protection
7
no cross protection
who are the carriers of foot and mouth disease
Convalescent ruminants
Some vaccinates
Wild animals
Hedgehogs
Rodents
Birds
where does the primary replication phase occur in foot and mouth disease
2-3 d
pharyngeal area
virus enters bloodstream and seeds target tissue
where does the secondary replication phase of foot and mouth disease occur
4-5d
Epithelium (mouth, feet, udder)
Muscles (heart), organs (lungs, kidneys, bowel)
Glands (thyroid, lymph)
how long does healing and recovery take for foot and mouth disease
<6 months
secondary infections
carriers
what are the clinical signs of foot and mouth disease
Anorexia
Pyrexia 41ºC
Dullness
Reduced milk yield
Death in youngstock
Abortion
Vesicles (blisters)
Salivation
Lameness
where do the vesicles of foot and mouth disease occur
Mouth
- Tongue, lips, gums, dental pad
Feet
- Interdigital space
- Coronary band
Udder
Snout
what are the ddx for oral lesions in cattle
al lesions:
Vesicular stomatitis
Bluetongue
Rinderpest
Mucosal disease
IBR
Malignant catarrhal fever
Necrotic stomatitis
Bovine papular stomatitis
Trauma or irritates
what are the ddx for teat lesions
Cow pox
Pseudo-cowpox
Bovine herpes mammillitis
Bluetongue
what are the ddx for foot and mouth in pigs
Swine vesicular disease
Vesicular exanthema
Enterotoxemia
Encephalomyocarditis virus
Abortion agents
what are the ddx for foot and mouth disease in sheep
Bluetongue
Foot rot
Orf
Enterotoxemia
Abortion agent
how is foot and mouth disease diagnosed
Virus — vesicular material
- PCR
- ELISA
- Cell culture (bovine thyroid, BHK)
- CFT
Antibody — serum
- ELISA
- Virus neutralization test
how is foot and mouth disease transmitted
Inhalation or ingestion
Highly contagious
Highly infectious
how does the foot and mouth virus survive
Virus survival is high in moist, cool conditions
The farm environment rapidly becomes heavily contaminated with the virus
what are the methods of spread of foot and mouth disease
Infected animals
Fomites
Infected animal products
Airborne
Carriers
what is the incubaiton period of foot and mouth disease
2-14 days
who are the carriers of foot and mouth disease
Convalescent ruminants
Some vaccinated ruminants
<9 months sheep
<3 years cattle
<5 years African buffalo
are there effective vaccines for foot and mouth disease
Effective vaccines
Vaccine delivery needs cold chain
Identification of vaccinated animals
- Vaccinate and slaughter
- Vaccinate to live
what are the key epidemiological features of foot and mouth disease
- Seven serotypes
- Stable in cool, damp, medium pH
- Multiplication is extremely rapid
- Highly contagious and highly infectious
- Carriers exist
- Effective vaccines available
who are the virus procuders of foot and mouth disease
pigs
who are the virus indicators of foot and mouth disease
cattle
who are the virus carriers of foot and motuh disease
sheep
inapparent infection
what are the prevention and control strategies of foot and mouth disease
Prevent introduction to country
- Import controls on live animals
- Import controls on animal products
- Monitor neighbouring countries
Prevent infection of livestock
- Post import check of live animals
- Swill feeding strictly controlled/banned
- Continuous surveillance
Prevent spread from infected animals
- Notification
- Movement controls and ‘stamping-out’
how do you notifiy foot and mouth disease if you suspect it
Veterinary surgeon or farmer must notify Police or Animal & Plant Health Agency (APHA) who initiate an immediate investigation
Vet stays on farm — consultation case with APHA veterinary officer
Vet leaves farm — report case — automatic farm standstill, police involved
if the veterinary official suspects foot and mouth disease what happens
Suspect premises defined and restricted, isolates all livestock, controls movement of people and all things
Temporary control zone <10km stock standstill around the suspect premises
Samples sent to FMD World Reference Laboratory
- Initial ELISA result in 4 hours
- Negative — restrictions lifted
- Positive — ‘stamping out’ policy implemented
what is the stamping out policy of foot and mouth disease
National animal movement restrictions
Exports of animals and products suspended
Infected premises (IP) procedures:
- Livestock valuation, slaughter, disposal, cleansing and disinfection
3km protection zone (PZ):
- Total agriculture standstill, intensive veterinary surveillance on all farms
10km surveillance zone (SZ):
- Ban on countryside activities, targeted surveillance
Controlled zones beyond 10km
National and local disease control centres established
what is the national disease control centre (NDCC) and what do they do in a suspected foot and mouth disease case
CVO in charge
Suspend exports
Implements national contingency plan
Monitors national disease control procedures
Assesses and changes control procedures
Informs minister/cabinet on epidemic progress
Informs EU and OIE of epidemic progress
Implements post-epidemic protocols
what is the local disease control centre role in a suspected case of foot and mouth disease
Slaughter and disposal of livestock on IPs
Cleansing and disinfection of IP
Tracings — contact animals (slaughter or isolation)
- Persons, vehicles
- Tracings ‘windows’
Epidemiological investigation
Veterinary surveillance — PZ & SZ, DCs, LLUs
Standstill implementation (3km PZ & 10km SZ)
Movements to abattoir, grazing etc — only by license
Post-epidemic surveillance in PZ and SZ
Restocking IPs — sentinels
what is the 3km protection zone in a foot and mouth disease case
Ban on agriculture movements
Biosecurity encouraged/enforced
Movement restrictions on all farms
Daily vet visits to premises contiguous to IP
Stock on all farms mapped
Milk code implemented
what is the 10km surveillance zone of foot and mouth disease
Ban on agriculture movements
Ban on countryside activities
Large livestock units restricted and subjected to daily vet visits (7 days)
Milk code implemented
All farms contacted
Biosecurity encouraged
what is the milk code for foot and mouth disease
Virus filters fitted to milk tankers
Drivers, tankers must clean and disinfect on/off farms and processing plant/dairy
Milk pasteurization
Tanker routes approved and monitored
how are the protection and surveillence zones implemented
by police
APHA
what is teh FMD virus plume modelling
viral output
- species affected
- number affected
- age lesions
Meteorology
- wind speed and direction
- relative humidity
- cloud cover
- precipitation
- topography
prediction model
- met officer computer
- viral plumes 10km grid
- risk assessment
summarize the principles and eradication of FMD
Stock standstill
- Infected premises
- Neighbouring farms
- Surrounding areas
Movement controls on
- Livestock hauliers
- Farmers
- Vehicles
- Events
- Dogs
- Shooting
- Parties
- Livestock markets
Stop virus spread
- Movement standstill
- Protection zone
- Surveillance zone
Stop virus production
- Kill infected animal
Kill the virus
- Destroy carcass
- Cleanse and disinfect
what are the future control of notifiable diseases
Enhanced biosecurity at farms, markets, shows
Swill feeding banned
Continuous farm livestock movement controls
Stricter import controls on meat products
Formalized contingency planning
Stamping out policy
Vaccination procedures in place
Pre-emptive informed by modelling
