PQS - Togaviruses Flashcards
Togaviruses are strongly resistant to the environmental conditions
F
They are enveloped = weak
Togaviruses are transmitted by mosquitoes
T
The clinical appearance of togavirus infection is dose dependent
T
Togaviruses cause airborne infection
F
Togaviruses cause encephalomyelitis in horses in East-Asia and in Australia only
F
Only in America
Several togaviruses are zoonotic agents
T
No vaccines are available against togaviruses
F
Inactivated, and in Venezuelan we use strain TC83, which is attenuated
Horse encephalomyelitis viruses are transmitted by ticks
F
Mosquitos
Abortion is the main clinical sign of togavirus infection results in abortion of horses
F
The leading clinical sign of togavirus infection is the frothy nasal discharge
F
Encephalitis
Togavirus infection in horses results in hepatitis
F
In the geographic distribution of equine togavirus migratory birds have an important role
T
Maintaning hosts in eastern and western
Rodents serve as reservoirs for the Western equine encephalomyelitis virus
T
Also birds!
Rodents serve as reservoirs for Venezuelan horse encephalomyelitis virus
T
Equine encephalomyelitis viruses are zoonotic
T
Equine encephalomyelitis viruses can cause asymptomatic infections
T
Horses encephalomyelitis vaccines defend against African horse sickness (cross protection)
F
Horse encephalomyelitis viruses are transmitted by ticks
F
Birds serve as reservoirs for the Eastern equine encephalomyelitis virus
T
Equine encephalomyelitis viruses can cause lameness in horses
T
Due to myelitis
Birds serve as reservoirs for Venezuelan horse encephalomyelitis virus
F
Western equine encephalitis causes the highest mortality
F
Western = mildest
Eastern = highest
Equine encephalitis can be diagnosed easily by gross pathology
F
No gross pahological signs
In Venezuelan horse encephalitis enteric symptoms can be observed too
T
Recovery from equine horse encephalitis induces immunity that lasts only 1 year
F
Life-long immunity
Equine encephalitis vaccines are available only for humans
F
An early sign of Eastern encephalomyelitis is biphasic fever
T
Eastern equine encephalomyelitis virus infects only horses
F
Zoonotic and euryxen
Mosquitoes are the principle vectors of equine encephalomyelitis viruses
T
Equine encephalomyelitis can cause abortion in human
T
If infected in 2nd or 3rd trimester
Wild birds are involved in the transmission cycle of eastern equine encephalomyelitis
T
Wild birds are involved in the transmission cycle of eastern equine encephalomyelitis
T
Viral equine encephalomyelitis is usually diagnosed on the basis of clinical signs
F
Clinical signs + season + geographical area
In endemic countries vaccines are available against equine viral encephalomyelitis
T
Some strains of Venezuelan horse encephalitis virus can be transmitted from horse to other hosts
T
Vaccination of horses in the Americas is used to prevent togavirus infections.
T
The Equine encephalitis virus may cause abortion
T
In humans YES
In horse NO
The Eastern Equine Encephalitis is present in Japan and Korea.
F
Only in America
Mosquitoes are the principal vectors of the Western Equine encephalitis.
T
No characteristic gross pathology lesions are seen in Equine encephalitis caused by
Togaviruses.
T
Eastern, Western and Venezuelan Equine encephalitis viruses are zoonotic agents.
T
Togaviruses caused encephalomyelitis of horses occurs frequently worldwide.
F
Only in America
The host range of horse encephalomyelitis togaviruses is wide.
T
American horse encephalomyelitis most frequently cause clinical signs is birds, horses and humans.
F
Aysymptomatic in birds
Humans are not susceptible to horse encephalomyelitis togaviruses.
F
American horse encephalomyelitis viruses represent several types and subtypes
T
Vectors of American horse encephalomyelitis Togaviruses are mosquitoes.
T
Main means of control of American horse encephalomyelitis are mosquito control and vaccines
T
Vaccines cannot be used to prevent Togaviruses caused encephalomyelitis of horse.
F
An early sign of Eastern encephalomyelitis is biphasic fever
T
Mainly ticks are the vectors of Equine encephalomyelitis viruses.
F
Serological cross-reactions are seen between certain encephalomyelitis viruses.
T
Equine encephalomyelitis viruses cause disease in horse populations worldwide.
F
Equine encephalomyelitis outbreaks are usually emerging in summer or rainy seasons.
T
After recovery from acute viral encephalomyelitis permanent lesions may remain in horses
T
The equine encephalomyelitis viruses are zoonotic agents.
T
Togavirus infections can unambiguously be diagnosed based on clinical signs and pathology.
F
Clinical signs + seasonality + geographic origin
No pathological lesions
In Europe vaccination of horses against equine encephalomyelitis is compulsory.
F
Togavirus infection results in abortion of horses
F
Horse encephalitis occurs only in America
T
Chikungunya virus is transmitted by the Asian tiger mosquito
T
Chikungunya virus causes joint pains, fever, rash and haemorrhages in humans
T
