Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
20 Cards in this Set
- Front
- Back
|
What are the three types of equine encephalitis virus?
|
western - dead end in horses
eastern - dead end in horses venezuelan - horses transmit back to mosquito |
|
|
What is the natural transmission of equine encephalitis virus?
|
viruses circulate in nature between mosquitoes and wild animals
reservoir hosts -become infected and develop high enough viral titers in blood to infect mosquitoes -WEE and EEE are the natural reservoir in birds -VEE rodents are the enzootic reservoir and horses are the epizootic reservoir |
|
|
What are Epizootic Cycles (Spillover)
|
Epizootics begin in nature (increased transmission of virus between mosquitoes and bird and spills over to incidental hosts
incidental host (outside t (cannot infect the natural cycle) are usually dead end = can not infect mosquitos -except VEE |
|
|
What is EEE?
|
Enzootic reservoir cycle between wild birds and mosquitos
many incidental hosts equine causes appear about 2 weeks before humans causes GI dz and hepatitis in swine causes fever, anorexia, lethargy riskfactor for humans: outdoor activities in an area with EEE infected mosquitoes |
|
|
What is the incubation period of EEE in humans?
|
3-10 days
90% people asymptomatic milkd flu like symptimes 50-90% of survivors will have mild to severe permanent neurological damage the vector Culex tarsalis are a bridge vector to infect other species no treatment |
|
|
What are the Clinical signs of WEE
|
Equine cases are rarely reported
-begin with fever, lack of appetite and lethargy -progresses with excitability and then drowsiness Human cases estimated that 1:1000 infectious in adults are symptomatic (more serious in children) -symptoms range from mild flue like illness to encephalitis, coma death -milk to severe neurologic deficits are seen in survivors |
|
|
How do you prevent EEE and WEE?
|
mosquito control
preventing bites vaccinate horses |
|
|
What is the veterinary risk for EEE and WEE?
|
in symptomatic horses with low titers risk is low except during necropsy
|
|
|
How is VEE transmitted?
|
***FOREIGN TO THE US***
enzootic transmission is between rodents and mosquitoes epizootic transmission is associated with equines highly pathogenic strains and different mosquitoes |
|
|
What are the clinical signs of VEE?
|
Equids
febrile or encephalitis disease humans 100% symptomatic with neurological symptom in 1% |
|
|
How do you prevent EEE?
|
report if in USA
in endemic areas use control methods sentinel surveillance |
|
|
Which virus has an equine reservoir?
|
VEE
|
|
|
What is the immunity from vaccines?
|
longlasting with natural infection
immunity from vaccines recommend annual booster |
|
|
What is West Nile Virus?
|
Flavivirus
maintained in a mosquito-bird-mosquito cycle birds have 1-4 day viremia post exposure |
|
|
How is West Nile Virus transmitted?
|
primarily spread through the bite of in infected mosquito
secondary transmission through bloodborne infectious, lab exposure and life immunity |
|
|
What are the signs of west nile virus?
|
in horses:
neurologic: ataxia, hypermetria, weakness, tetraparesis, recumbency, death Humans: 80% asymptomatic 20 mild febrile illness |
|
|
What are Hantaviruses?
|
Bunyavirus that rodents are the reservoir
rodents are asymptomatic and shed for weeks to months (saliva, urine, feces) |
|
|
How is Hantavirus transmitted?
|
primarily aerosol
secondary by bite |
|
|
What are the clinical signs in humans for huntavirus?
|
severity always depends upon species of virus
-hantavirus pulmonary syndrome see fever, chills, maylgia,headage increased vascular permeability in the lungs Fatal in up to 40$ of human cases -Hemorrhagic Fever with Renal Syndrome the old world disease petechial hemorrage, renal damage and cardiovascular shock |
|
|
What are the risk factors for hantavirus?
|
human: rodent contact
people who work with rodents or rodent habitats prevent by reducing human exposure |
