48. Equine encephalomyelitis caused by togaviruses (Zoon.). Flashcards
Equine Encephalomyelitis: Family & Genera
- Family: Togavitidae
- Genera:
- Alphavirus
- Rubivirus
Equine Encephalomyelitis: Notable Alphavirus species
- Eastern equine encephalitis virus
- Western equine encephalitis virus
- Venezuelan equine encephalitis virus
- Getah virus
Equine Encephalomyelitis: Notable Rubivirus genus
Rubella virus
Eastern, Western & Venezuelan Equine Encephalomyelitis: Occurrence
- Eastern: Canada; USA (east coast); Central America
- Western: Canada; USA (west coast); Mexico; S. America
- Venezuelan: USA (southern); Central & South America
Equine Encephalomyelitis: Alphavirus summary
NOTIFIABLE & ZOONOTIC DISEASAE
- Enveloped; ssRNA
- Weak resistance in the environment
- Arbovirus - Mosquito transmission
Equine Encephalomyelitis: Alphavirus - Affected species
Euryxen virus
- Horse*
- Human*
- Donkey
- Mule
- Rodents
- Birds
*Dead-end hosts
Equine Encephalomyelitis: Alphavirus - Epizootiology
- Eastern Equine Encephalomyelitis virus
- Bird-Mosquito cycle
- Long-distance transmission - Bird migration
- Seasonal epidemics; Weather-related
Equine Encephalomyelitis: Alphavirus - Epizootiology
- Western Equine Encephalomyelitis virus
- Bird-Mosquito-Rodent cycle
- Dependent on host preference of mosquitos
Equine Encephalomyelitis: Alphavirus - Epizootiology
- Venezuelan Equine Encephalomyelitis virus
- Horse/rodent-Mosquito-Horse/rodent cycle
- Summer/rainy season
- Enzoonotic in rodent
- Epizootic in Eq - CSx & Death
Equine Encephalomyelitis: Alphavirus - Pathogenesis
Mosquito bite → Regional LN → 1st Viraemia → Viscera → 2nd Viraemia
Equine Encephalomyelitis: Alphavirus - Pathogenesis (Transplacental infection)
Embryo developmental problems: Hypoplasia; Hydrocephaly
Equine Encephalomyelitis: Alphavirus Pathogenesis - The course is dependent on…
Age & Dose
Equine Encephalomyelitis: Virulence
- Eastern
- Western
- Venezuelan
- Eastern: 75-100%
- Western: 10-50%
- Venezuelan: 32-86%
Equine Encephalomyelitis: Convalescence
- Life-long immunity
- Partial cross-protection
Equine Encephalomyelitis: Incubation time
1-3 Weeks