Exam 3 - Rhabd-Reoviruses-Rubella

Question 1

Rhabdoviridae
Rabies
morphology

Answer 1

• rod-shaped
• enveloped
• ssRNA
• neurotropic
• N,P,M,G,L structural proteins

Question 2

Rhabdoviridae
Rabies
epi/transmiss

Answer 2

• worldwide (developing world)
• 6k cases 2012 in US; wild animal vectors
• 50,000ish deaths/year
• zoonotic (duh): DOGS, varmints, a few bats
• males<16 yo

Question 3

Rhabdoviridae
Rabies
path

Answer 3

• break in skin
• replication in myocytes
• muscle spindle->nerve->neuromusc jxn Ach receptor
• retrograde axonal mvmt to dorsal root for replication
• centripetal spread to CNS (stem, thalamus, BG, cord)
• finally, systemic spread via preiph nerves

Question 4

Rhabdoviridae
Rabies
risk factors

Answer 4

• no barriers to bite
• # of bites
• face bite>extremities

Question 5

Rhabdoviridae
Rabies
clin pres/sx

Answer 5

4 phases
1) Asx incubation 30-90 days
2) 2-10 days prodrome: malaise, fever, fatigue, bx/mood sx,
paresthesia at innoc. site
3) 2-7 days acute neuro sx: 80% "furious" (seizurehydrophob, delirium,
autonomic dysfxn), 20% paralytic
4) 7 days coma
5) death (resp arrest)

Question 6

Rhabdoviridae
Rabies
Dx

Answer 6

• DFA stain of nape of neck (virus local to hair follicles)
• negiri bodies on HE stain
• PCR of saliva, CSF
• test that critter’s brain tissue!
• ^T2 signal of hypo/thalamus, hippcamp on MRI

Question 7

Rhabdoviridae
Rabies
Prevention

Answer 7

-vaccination of nannermals, at-risk spelunkers

Question 8

Rhabdoviridae
Rabies
tx

Answer 8

• wound care with povidone/iodine
• Rabies Ig infiltrated at site
• vaccine days 0,3,7,14
• induce coma at onset of sx (“Milwaukee protocol”)
• Milwauk drugz: ketamin, midazolam, ribavirin, amantadine

Question 9

Reoviruses

etymology

Answer 9

respiratory enteric orphan viruses :(

Question 10

Reoviruses

morphology

Answer 10

• 10-12 sements dsRNA

- non-enveloped, icosahedral capsid

Question 11

Reoviruses
coltvirus
syndrome

Answer 11

Colorado Tick Fever

Question 12

Reoviruses
coltvirus
transmiss/epi

Answer 12

• adult tick bite

- March-Sept

Question 13

Reoviruses
coltvirus
path

Answer 13

• infects RBCs

- then viremia

Question 14

Reoviruses
coltvirus
clin pres/sx

Answer 14

• self-lim’d febrile illness 3-6 days after bite
• fever for 3 days, goes away 1 day, back for 3 days
• aseptic meningitis in 5-10% of kids

Question 15

Reovirus
rotavirus
transmiss/epi

Answer 15

-mostly group A (of A-G)
-fecal-oral route
-most commone cause of severe diarrhea
worldwide in children <5yo
-first infxn btwen 2 and 24 mos
-child care centers, nosocomial
-winter months, drier conditions
-resistance to chlorination of water supply

Question 16

Reoviruses
rotavirus
path

Answer 16

• infects small bowel

- progeny viruses leave cell via lysis

Question 17

Reoviruses
rotavirus
clin pres/sx

Answer 17

• children 2-3 yrs
  1) fever, vomit for 3 days
  2) diarreha 4-8 days, ab pain
  3) sx ass’d w/ vol depletion

Question 18

Reoviruses
rotavirus
complications

Answer 18

• AIDS, iummunosuppression

- can cause SIDS, pneumonia, nec enterocolitis

Question 19

Reoviruses
rotavirus
dx

Answer 19

-not needed (self lim’d)
-but if ya really need it, ELISA, stool EM,
latex agglutination

Question 20

Reoviruses
rotavirus
tx

Answer 20

• NO ANTIVIRALS

- supportive care

Question 21

Reoviruses
rotavirus
prevention

Answer 21

• vaccine

- some intussusception… :/

Question 22

Togaviridae
Rubella
AKA (syndrome)

Answer 22

• German measles
• man kriegt diese krankheit von schoener maedchen!
• kinder kriegen diese krankheit wenn sie boese sind!

Question 23

Togaviridae
Rubella
morphology

Answer 23

• enveloped, non-seg’d, + sense RNA

- capsid

Question 24

Togaviridae
Rubella
transmiss/epi

Answer 24

• spring
• moderate contagion
• aerosolized droplets from resp tract
• 5-9yo children
• increasingly present in immigrants, older children

Question 25

Togaviridae
Rubella
clin pres/sx, gen

Answer 25

• 12-23 day incubation
• infx’ous 5 days before, 3 after sx
• rash appears as immunity develops
• macpap rash (3-5 days)
• lymphadenopathy
• resp sx
• arthralgia (adults)

Question 26

Togaviridae
Rubella
Congential

Answer 26

• “CRS”
• rare
• more likely if infxn early in pregnancy
• senosorineural deafness, glaucoma/cataract, heart defects, ID
• microcephaly, hepatomegaly
• blueberry muffin rash (lol!)

Question 27

Togaviridae
Rubella
dx

Answer 27

• clinical pres
• leuopenia w/ atypical lymphocytes
• ELISA
• PCR of amontic fluid for CRS

Question 28

Togaviridae
Rubella
tx

Answer 28

• vaccine!

- supportive