Arbo 3 Flashcards
Reoviridae genus
Coltivirus: Colorado Tick Fever Virus
Coltivirus structure
- 12 Double stranded RNA segments
- NON enevloped
- icosahedral
Coltivirus replication cycle (5 steps)
- endocytosed, enters lysosome
- core particle primary transcript
- Translated into +/- strands in cytoplasm
- replicase creates + strand from the - one
- capsid assembly and release
Colorado tick fever is a ____, _____ illness
nonspecific, febrile
Coltivirus clinical findings (4)
- Tick bite
- Saddleback Fever
- Flu-like symptoms
- Transient Rash
(Complication of Encephalitis or pericarditis)
Coltivirus infects _______ cells.
What effect does this have?
Bone Marrow cells
this halts development of blood cell types (PMN, eos, baso’s)
When do Coltivirus symptoms occur
4-5 days after tick bite
Significance of the first two weeks of Coltivirus infection
free virus can be found in the blood
after which it circulates within erythroblasts
When does Coltivirus antibody appear?
two weeks after symptom onset
Coltivirus lifespan in blood
can be isolated for 6 weeks
BUT can live in RBC for life of the cell
Coltivirus resevoir and transmitter
Squirrel/rodent resevoir
Wood Tick is transmitter
What tick spreads Coltivirus?
Rocky Mountain wood tick
(Dermacentor andersoni)
90% of Coltivirus cases happen during…
april-july
Coltivirus control
stay away from ticks
check yo pets
get out of your skin if embedded
Filoviridae diseases
Ebola
Marburg
Characteristics that filoviridae share
Genome structure
Zoonotic
Damage the microvasculature = hemorrhage
Filovirus organism structure
ss (-) RNA
Encodes 7 proteins
Enveloped filaments
Helical
Filovirus nucleocapsid enclosed in an envelope that contains…
one glycoprotein
Filovirus replicates in the
cytoplasm
Filovirus (ebola) causes ______ infection
hemorrhagic
Ebola rash appearance and time
macropapular, appears at 5 days
Signs of recovery occur at day ____ and are concurrent with…
Day 7
With antibody response
Ebola transmission and reservoir
Unknown
possibly bats
Major characteristic of Ebola (filo) infection is…
destruction of the immune system
especially the breakdown of endothelial cells
Ebola cell damage due to ____
Cytokine release from Monocytes
Ebola cytokine dysregulation promotes ______ and ______
hemorrhage + vasomotor collapse
Ebola vector
Not identified
Rotavirus serogroups
A-E
Rotavirus genome and structure
nonenveloped
dsRNA
3 capsid layers + inner core
(Outer capsid VP4)
Rotavirus VP4 protein is located on _____ and functions to aid _______
Outer capsid
host attachment
Is rotavirus segmented or not?
Yes
11 segments of dsRNA
Rotavirus transcription and translation occur in _______
Inner core = transcription
Cytoplasm = translation
What is different about the replication of Rotavirus?
replicates in progeny core
uses positive RNA template
Rotavirus release from cell, two steps…
buds into ER
release by cell lysis
Rhabdovirus genus
Lyssavirus
Rhabdo shape and structure
bullet shaped helical, enveloped
ss (-) RNA
Rhabdo: associated proteins
NPMGL
(nucleo, phospho, matrix, glyco, polymerase)
Rhabdo replication
- Binds using G protein
- Pinocytosis into cytoplasm
- Endosome fusion and release RNP into cytoplasm
- L gene (pol-ase) makes 5 mRNAs + 1 full (+)RNA
- Translation of NPMGL (G = processed in ER and Golgi)
- +RNA serves as templates for full length (-) RNA
- Assemble NPL around RNP core, M forms capsule (matrix)
- Bud from PM and release
Rhabdo periods (and # of days for each)
Incubation (20-90)
Prodromal (2-10)
Neurological (2-7)
Rhabdo travels via..
retrograde axonal transport
Rhabdo pathogenesis duration depends on…
size & site of exposure
human/animal immunity
Rhabdo replicates in _____
muscle at the site of innoculation
Rhabdo concentrates in ______
salivary glands
common reservoirs for rhabdo
bats, foxes, raccoons, skunks
Rhabdo Dx
Histopathology
(also electron micro,
direct elisa/immunochemistry)
signs of rhabdo in histopathology are… (5)
- mononuclear infiltration
- perivascular cuffing (lymph/PMN)
- Lymphocytic foci
- Babes nodules
- NEGRI BODIES
Rhabdo vaccine is unique in that it is adminitered
Post exposure
Other measures taken after exposure to rhabdo (other than post exposure vax)
Clean site with soap and water
Rhabdo vax administration schedule after exposure?
Days - 0, 3, 7, 14, 28
Is there a pre exposure rhabdo vaccine?
Yes
3 doses
What is the Wisconsin rabies treatment protocol?
Ketamine
Ribavirin
Amantadine