Zoonotic Viral Diseases I/II Flashcards
This deck will cover all the new zoonotic viruses that weren’t already covered in another deck.
Carry on
Let’s start with rabies. Describe the structure
-ssRNA, enveloped, bullet-shaped, helical nuclear capsid
Who carries rabies around?
- bats
- raccoons
- skunks
- foxes
- coyotes
Describe the pathophys of rabies virus?
Virus contains glycoprotein which binds to nicotinic acetylcholine receptors on postsynaptic membrane of NMJ.
Virus travels retrograde via peripheral nerves to dorsal root ganglia; affects pyramidal cells of hippocampus and Purkinje cells
What sx will you get with rabies?
salivation, dysphagia (spasms in muscles of larynx/throat), muscle spasms, fever, acute encephalitis, uniformly fatal (untreated) with incubation of weeks/ months`
Dx of rabies???
dFA of brain (direct fluorescence antibody stain).
What will you see on Histo for rabies?
Negri bodies=eosinophilic cytoplasmic inclusion bodies (in pyramidal cells of hippocampus and purkinje cells)
What do you do when you get bit by a bat and you’re like OMG I’M GONNA GET THE RABIES WHATDOIDOWHATDOITDOWHATDOIDO
after bite in someone who was never vaccinated→ post-exposure anti-rabies vaccine and passive antibody (HRIG)
What is the structure of Coronavirus?
+ssRNA, helical capsule
What are the sx of Coronavirus?
Can cause:
- acute bronchitis that leads to ARDS, 2. common cold
- SARS
Source of coronavirus
bats and other animals (civet) in Asian game market
What is MERS-CoV?
MERS-CoV: Middle East respiratory syndrome coronavirus. Likely from camels, carried by bats
How do you dx coronavirus?
antibodies to SAR confirmed with PCR
Tx for coronavirus?
- broad spectrum antibiotics
- ribavarin
- corticosteroids
Where will you get Hendra virus?
flying fox bat, horses in Australia
Where will you get Nipah virus?
Bat, pigs in Malaysia
What kind of viruses are Hendra and Nipah virus?
Paramyxoviruses
What can Nipah/Hendra virus cause?
Multisystemic vasculitis→ thrombosis, ischemia, and necrosis. Can lead to disease of brain (acute encephalitis), lung (pneumonitis) and spleen.
Structure of Hantavirus? Genome?
-ssRNA, enveloped
Genome contains 3 RNA segments: L, M, S
How is Hantavirus transmitted?
Inhalation of infected rodent excrement or direct contact through skin
What does Hantavirus cause?
HFRS (hemorrhagic fever w/ renal syndrome) aka hantavirus disease =fever, HA, hemorrhage, acute renal failure.
What can Sin Nombre virus cause?
HA, back/abd pain, fever, chills, nausea, blurred vision, HFRS, HPS (Hanta pulmonary syndrome**this syndrome is mostly caused by Sin Nombre virus, despite the name)
How is Sin Nombre virus transmitted?
Inhalation exposure in the Four Corners region of US
Tx for Sin Nombre?
Supportive
What kind of virus is Sin Nombre virus?
Bunyavirus
Strucutre of Flavivirus?
+ssRNA, enveloped, non-segmented
Tell me some things about Japanese encephalitis (Caused by flavivirus)
- Transmission
- Dx?
- Tx?
- transmission involves culex mosquitoes, birds and pigs
- Dx: serology
- Tx: NONE WAH
Are most infections by Japanese encephalitis super duper bad like you’re gonna die today kind of bad?
No. No, it’s actually usually subclinical. Relax, kid.
There are two kinds of Yellow Fever (caused by flavivirus). Tell me about them.
- Jungle form: natural reservoir of dz, cycle in non-human primates and forest mosquitoes. Humans incidentally infected when in jungle.
- Urban form: transmitted between humans by Aedes aegypti mosquito.
What are the sx of Yellow Fever?
- chills
- HA
- f/n/v
- “Black vomit” and liver dz→ jaundice
- blood diarrhea
- backache
Dx, Tx, and vaccine for Yellow Fever?
Dx: serology
Tx: none. wah.
Vaccine: live attenuated
Where are you most likely to get Yellow Fever?
W. Africa
S. America
Where are you most likely to get Dengue fever?
SE Asia
Africa
Caribbean
S. America
What are the sx of dengue fever?
- “break bone fever”
- lymphadenopathy
- myalgia
- bone/joint pains
- headache (retro orbital)
- maculopapular rash.
What can happen to people previously infected with a different Dengue serotype?
- hemorrhagic fever
- renal failure
- septic shock
How many serotypes of Dengue are there? What’s special about type 2?
4 types
type 2 affects the bone marrow -> thrombocytopenia->spontaneous bleeding.
Dx and Tx of Dengue fever?
Dx: serology
Tx: Supportive
What’s the reservoir and vector for West Nile virus?
reservoir = birds vector = culex mosquito
What are the lovely sx of West Nile virus?
myelitis → flaccid paralysis, seizures and coma; encephalitis
Tx for West Nile virus?
supportive
Structure of togavirus?
+ssRNA, enveloped
What sx do you see with togavirus?
Flu-like sx→ encephalitis 3-10 days post infection. Generally self-limited.
Possible paralysis, mental disorders, death
Transmission of togavirus?
Reservoir=Horse
Vector=mosquito
Tell me about EEE?
found in Eastern U.S. Rarest. Mostly asymptomatic or nonspecific fever. Neuro involvement seen in 1 in 23. 30% fatality.
Tell me about WEE?
Found in Western U.S.
More frequent.
Neuro involvement seen in 1 in 1000 adults, 1 in 25 infants (may cause permanent brain damage in infants)
60% of survivors have neuro impairment.
Tell me about VEE?
Found in Central and S. America; incompletely understood.
Sx=acute fever 2-6 days post infection with major systemic sx
Neuro involvement less common and less severe than EEE/WEE.
Is there a treatment for togavirus causing EEE, VEE or WEE?
NO
Structure of Reovirus?
**dsRNA, 9-12 segments, non-enveloped, icosahedral
Two reoviruses you should know
- Rotavirus
2. Colorado tick virus
What are the sx of rotavirus? Who is most at risk?
1 cause of watery diarrhea in kids
What toxin mediated the watery diarrhea in rotavirus?
NSP4 toxin which increases chloride permeability
Transmission of rotavirus?
fecal-oral transmission
What are the sx of Colorado Tick virus?
Colorado tick fever→ generally mild or subclinical. Acute dz resembles dengue→ fever, chills, HA, myalgia, arthralgia, photophobia, lethargy.
Found in Rocky Mountain states; differentiated from RMSF because no rash.
Transmission of Colorado Tick Virus?
Wood tick Many reservoirs (squirrels, rabbits, deers)
Tx for rotavirus?
Oral rehydration
Vaccine for rotavirus?
Oral, live attenuated (give before 3 months age). Increases risk of intussusception due to enlargement of Peyer’s patches
