sleeping sickness, influenza and herpes virus in the horse test Flashcards
what is the scientific name for sleeping sickness?
Equine encephalomyelitis
what characterizes equine encephalomyelitis
it is characterized by CNS dysfunction and moderate to high mortality
what are the alphaviruses for sleeping sickness
EEE,WEE,VEE
what does EEE,WEE,VEE stand for in sleeping sickness
EEE-eastern equine encephalomyelitis
WEE- western equine encephalomyelitis
VEE- Venezuelan equine encephalomyelitis
where does WEE outbreak
primarily occur in the west and Midwest US
what happened in the 1930s in sleeping sickness
> 180,000 horses dies
current morbidity is _______ because of ______. in sleeping sickness
low, vaccines
where does EEE affect in sleeping sickness?
epizootics along the eastern seaboard and gulf coast
where does VEE affect in sleeping sickness
first isolated in 1938 in venezuela
what are the reservoir hosts for sleeping sickness
birds, rodents, and reptiles
what are the vectors for sleeping sickness
mosquitos are the transmission vector for the spread of these viruses
how many different types of mosquitos has sleeping sickness been isolated from
27 different types of mosquitos in the US
how is the infection spread by mosquitos
spread from the reservoir hosts to horses by mosquitos carrying virus
what kind of viremia do WEE horses have in sleeping sickness
have a low viremia which means that there is a low amount of virus in the blood
because of the low viremia , horses are considered what in WEE sleeping sickness
they are considered to be a dead end host for WEE- this means that infection does not spread from an infected horse to other healthy horses
what kind of viremia does VEE in sleeping sickness get associated with
it is a high viremia and because of this viremia this infection can spread form horse to horse
what does the viremia for VEE cause for sleeping sickness
the viremia results in viral shedding in body fluids which causes the infection to go horse to horse via the aerosolized respiratory secretions or direct contact with body fluids
what type of viremia does EEE cause in sleeping sickness
horses infected with EEE have a transient but significant viremia
epizootics are _______ in temperate region, occurring during _______ months but not during ______months in sleeping sickness.
seasonal, warm, cold
in what state does transmission occurs throughout the year with a peak in what season in sleeping sickness?
in florida and it happens in the summer
what are the clinical signs of encephalomyelitis in the classic form of the disease
- initially depressed with neurologic signs generally occurring 5 days post infection but include
- low grade fever
- altered mentation
- impaired vision
- aimless wandering
- head pressing
- circling
- inability to swallow
- irregular gait
- paresis and paralysis
- terminally, convulsions and death
what happens when the disease is terminal in sleeping sickness
convulsions and death occur and most deaths occur within 2-3 days after onset of C.S.
what happens to the surviving horses with sleeping sickness
they may be dummies because of the permanent neurologic damage
what is the mortality rate for WEE in sleeping sickness
20 to 50%
what is the mortality rate for EEE in sleeping sickness
50 to 90%
what is the mortality rate for VEE in sleeping sickness
50 to 75%
what is the presumptive diagnosis based on for sleeping sickness?
usually based on the clinical signs
the serologic titers for sleeping sickness show what
these titers will show a 4 fold increase between the acute and convalescent samples which will give you a positive diagnosis (the 1st antibody titer should be low but vaccinations may show a false increase in the amount of antibodies)
how is the virus isolated from horses with sleeping sickness
the virus may be isolated from the CSF of horses with an acute infection
what are the 3 types of diagnosis options that are available for sleeping sickness
presumptive, serologic titers, and virus isolation
what is the treatment for sleeping sickness
there is no specific therapy for viral encephalitis supportive care includes-
– i.v fluids
– stomach tube feeding
– anti- inflammatory agents
– anticonvulsants
there is no specific antiviral drugs available
what is the public health significance of sleeping sickness
- the C.S in man vary from mild flu-like symptoms to death
- children, the elderly, and immunosuppressed individuals are the most susceptible
- is a zoonotic disease and can get from birds
- there is no vaccination fro humans
what is the mortality rate for human encephalitis for EEE, WEE, VEE?
EEE- up to 75%
WEE- 20%- not really deadly
VEE- 40%- does not happen in this country