81. Vesicular stomatitis, ephemeral fever. Flashcards
1
Q
Characteristics and genera?
A
Characteristics
- 100-430 nm, bullet shape (vertebrate) rod shape (pathogenic to plants)
- helical ʹ ssRNA, ENVELOPED
- low resistance: infective ʹ if dehydrated for 1 ʹ 2 days, in carcass 1 ʹ 2 weeks
- 5 structural proteins:
- G: adhesion/bind to cell, can neutralise!
- cell mediated response
- Biological properties
- Culture ʹ possible but not characteristic CPE, good antigen
Genera
- Vesiculovirus genus: Vesicular stomatitis virus; Spring viraemia virus of carp
- Lyssavirus genus: Rabies virus, others
- Ephemerovirus genus: Ephemeral fever virus
- Novirhabdovirus genus: Viral haemorrhagic septicaemia virus (trout); Infectious
- haemopoietic necrosis virus (salmonidae)
2
Q
Vesicular stomatitis Occurrence ?
A
Vesicular stomatitis
- Notifiable, Zoonotic
- Rhabdoviridae, Vesiculovirus, Vesicular stomatitis virus
Occurrence:
- America (US, South, Middle) to France and S Africa
- Similar viruses in Iran and Iraq but no clinical signs
- OIE: no cases in 2015-2020
3
Q
Aetiology of vesicular stomatitis?
A
Aetiology:
- Several serotypes and variants (Indiana, New Jersey)
- Cross protection is different, great variability
- Susceptibility: horse, cattle, swine, sheep, goat, lama, human, bat, rodents etc.
- (wild: asympt)
4
Q
Epidemiology of Vesicular stomatitis?
A
Epidemiology
- Seasonal variation (because sand flies can transmit)
Infection:
- different arthropods (sand flies, midges, flies)
- contact (shed in saliva),wounds
- Susceptibility is increasing with age
- Long lasting immunity
- Morbidity high, mortality low
5
Q
Pathogenesis of vesicular stomatitis?
A
Pathogenesis
- Indirect/direct
- Vesicle forms at the place of entry, replicates
- generalisation
- (couldn’t confirm viraemia) oral, test, coronary band: vesicles
- heals, frequently
- subclinical
- IR: long lasting Igs
- long immunity, protected 1 year
Clinical signs:
- incubation = 1-3 days
- fever, anorexia, vesicles (can rupture!) (mouth, leg, teats), erosion, salivation,
- limp, benign
- healing about 2 weeks
- Inappetence, decreased milk production
6
Q
Diagnosis, differential diagnosis tretament and prevention and public health impact?
A
Diagnosis
- Epidemiology ʹ clinical signs
- Detection of the agent
- Detection of the virus: CFT, IF, ELISA, El-micro, PCR
- Isolation of the virus: tissue culture, egg, mouse
- Detection of antibodies: CFT, VN, ELISA
Differential diagnosis: FMD, SVD, VES
Treatment: not necessary, disinfection
Prevention:
- Endemic: seroconversion, vaccination (inactivated ʹ live), arthropod control
- Free countries: Vet administration rules, notifiable
Public health impact
- Zoonosis; Widespread seropositivity
- Flu-like clinical signs (fever, muscular pain)
- Vesicles are uncommon (mouth, anus),
7
Q
Ephemeral fever Occurence, aetiology, epidemiology clinical signs?
A
Rhabdoviridae, Ephemervirus, Bovine ephemeral fever virus
Occurrence:
- Africa, SE-Asia, Australia, Middle East; Tropical, subtropical areas
Aetiology:
- Ephemervirus genus (related to some Lyssaviruses)
Epidemiology
- Not contagious, no spreading with discharges
- Spread by mosquitoes
Clinical signs
- only in cattle and buffalo
- Seroconversion in other Ruminants
- Seasonal differences, dont carry after recovery , good immunity & antigenicity
- High morbidity, low mortality
8
Q
Pathology, Diagnosis treatment and prevention of Ephemeral fever?
A
Pathology:
- hemorhages, edema, polyserositis, pleuritic, perihepatitsi,
- pneumonia, emphysema
Diagnosis
- Epi - Clinical signs
- Detection of the agent
- Detection of the virus: IF, PCR
- Isolation of the virus: brain of suckling mice, tissue culture
- Detection of antibodies: VN, ELISA; paired samples (seroconversion in endemic!)
Treatment:
- rest, symptomatic treatment (anti-inflammatory), convalescence
Prevention:
- mosquito control, inactivated and attenuated vaccine
- Endemic: movement restrictions, mosquito control, attenuated vaccine (LIVE)
- Free: inactivated vaccine
