TogaVirus Flashcards
togavirus important viruses
- Chikungunya virus
- Eastern equine encephalitis virus
- Getah virus
- O’nyong-nyong virus
- Semliki Forest virus
- Sindbis virus
- Venezuelan equine encephalitis virus
- Western equine encephalitis virus
Eastern-, Western, and Venezuelan Equine Encephalomyelitis
description
Acute neurological diseases of horses present only in the Americas, transmitted by mosquitoes (thus seasonal) and affect several other species including human
ZOONOTIC
Venezuelan Equine Encephalomyelitis occurrence
USA southern states – Central and South America
Western Equine Encephalomyelitis occurrence
Canada – USA west coast – Mexico – South America
Eastern Equine Encephalomyelitis occurrence
Canada - USA east coast – Central America
in which other animals can Equine Encephalomyelitis be detected
rodents and birds but without disease
Toga virus resistancy
envelopped, weak resistance to environment
what temparature is convinient for toga virus
37°
in mosquitoes can only be reached in summer time
In togavirus transmission, what role does the mosquitoe play?
biological vector
Virrus rep in the mosquito after blood meal
Transovarial transmission from one generation to another, they hatch inefcted
togavirus euryxen or stenoxen?
euryxen
what kind of hosts are humans for toga virus
dead end host
virus titre in the blood during viraemia is too low for transmission
Eastern Equine Encephalomyelitis cycle type
bird and mosquito
Eastern Equine Encephalomyelitis season
warm, rainy summer and fall; wetlands
Eastern Equine Encephalomyelitis distance of transmission
long distance, via bird migration
Eastern Equine Encephalomyelitishorse and humans are which kind of hosts
dead end
Western Equine Encephalomyelitishorse and humans are which kind of hosts
both dead end
Venezuelan Equine Encephalomyelitishorse and humans are which kind of hosts
horse is not a dead end
can induce high virus titre anaemia in the
horse than the mosquito can transmitt it from horse to other animals/humans
Western Equine Encephalomyelitis cycle types
bird- mosquito- rodent cycle
Venezuelan Equine Encephalomyelitis cycle
rodent/horse-mosquitoes-rodents/horse
Venezuelan Equine Encephalomyelitis season
summer/rainy
Equine Encephalomyelitis pathogenesis
bite
injection of virus into blood
reaches regional lymph node (prim. rep)
Viraemia (1st)
visceral organs
back to blood (viraemia)
Can Equine Encephalomyelitis appear as an unapparent infection
yes, no fever, low titre viraemia (too low to cause damages in body)
which Equine Encephalomyelitis has the highest mortality rate?
Eastern < Western < Venezuelan
how long is immunity after Equine Encephalomyelitis infection
life-long
but can be long lasting brain damage signs
Equine Encephalomyelitis incubation time
1-3wks
Equine Encephalomyelitis peracute form
fever (>41°), shock death
Acute/Subacute form of Equine Encephalomyelitis
Biphasic fever (2 viraemia)
signs of encephalitis, myelitis
venezuelan Equine Encephalomyelitis acute specific symptoms
+ colic & diarrhea
terminal stage of Equine Encephalomyelitis symptom
horse lies down and turns in circles
“digging own grave”
can there be a chronic form of Equine Encephalomyelitis
rare, 1-2wks, death can occur too
(recovery but with permanent damages)
Pathoglogy of Equine Encephalomyelitis
macroscopically unspecific
histopath of Equine Encephalomyelitis
encephalitis, myelitis (grey & white matter affected)
(lots of immune cells)
Diagnosis of Equine Encephalomyelitis
NOTIFIABLE DISEASE
season, geographic
blood, brain samples
DD of Equine Encephalomyelitis
with CNS signs:
Rabies, Rhinopneumonitis, West Nile fever, St Louis encephalitis, Japanese encephalitis, Getah virus
prevention of all three Equine Encephalomyelitis
OIE listed and NOTIFIABLE in EU
Equine Encephalomyelitis immunisation
Inactivated, trivalent vaccine- meaning it contains all 3 viruses
- 2× basic immunisation + yearly repetitions
- Venezuelan: strain TC 83 – attenuated (virus is alive but weakened, thus does
not cause clinical signs)
is Equine Encephalomyelitis zoonotic?
YES
public health consideration of Equine Encephalomyelitis in humans
Infection of pregnant mother in the 2nd-3rd trimester can lead to abortion, newborn cerebral necrosis
children more sensitive
human vaccine present
Where is the Chikungunya virus found?
Africa, india, indonesia
what is the vector of the Chikungunya virus
asian tiger mosquito
human CS of Chikungunya virus
joint pain, fever, rash, haemorrhages
O’nyong-nyong, Igbo Ora is where? and causes what?
Africa
fever & rash in humans (joint pain)
Ross River fever is where ? and causes What?
- Australia, New-Guinea, Fiji-islands
- Human: fever, arthritis, rash
Getah virus is where ? and causes What?
- Horse encephalitis (in Japan)
- Not zoonotic
Sindbis virus where?
Africa, europe
Semliki forest virus where ?
Africa