Rhabdo and Filo Viruses

Question 1

• bullet shape, enveloped viruses that encode 5 structural proteins
• helical nucleocapsied, (-)ssRNA, virion particle containes RNA directed RNA polymerase

Answer 1

rhabdoviruses

Question 2

which antigenic site of the rabies G protein is responsible for neutralizing antibodies and neuronal receptors?

Answer 2

antigenic site III

Question 3

inclusion body of the Rabies virus?

Answer 3

negri body

Question 4

• acute infection of the CNS
• mammals infected with virus: bats, raccoon, skunk, fox, dogs, cats, cattle
• 99% mortality once symptoms apparent
• allow post exposure vaccination

Answer 4

rabies virus

Question 5

rabies pathogenesis?

Answer 5

1. virus inoculated through bite of animal
2. viral replication in muscle tissue
3. virus enters peripheral nervous system
4. passive ascent via sensory fibers
5. replication in dorsal ganglia
6. rapid ascent in spinal cord
7. infection of spinal cord, brainstem, cerebellum, other brain structures
8. descending infection via nervous system to eyes, salivary glands, skin, pancreas, kidney

Question 6

incubation period of rabies?

depends on what factors?

Answer 6

2-12 weeks, can be as short as 4 days or longer than a year

concentration of virus introduced, proximity of wound to brain, severity of wound, host immune status

Question 7

classical rabies:

• prodromal phase?
• neurological phase?
• coma or paralysis phase?

Answer 7

• fever, headache, malaise, fatigue anorexia, lasts 2-10 days
• hyperactivity, disorientation, hallucinations, seizures, hydrophobia, lasts 2-7 days
• mental deterioration which leads to sudden cardiac or respiratory arrest, coma for hours to days prior to death

Question 8

amino acid at position 333 of G protein in antigenic site III:

• ______ in pathogenic rabies
• _______ in non-pathogenic variants

Answer 8

arginine

glutamine, isoleucine

Question 9

most important immune response in clearing rabies?

Answer 9

humoral: anti-G protein antibodies contain determinants for virus neutralizing antibodies

Question 10

urban rabies: _______ account for more than 99% of infections

Answer 10

canines

Question 11

_________ biopsies can be used in RT-PCR assays to amplify the rabies virus sequences

Answer 11

saliva and skin, due to anterograde trasnport

Question 12

post exposure rabies prophylaxis?

Answer 12

wound treatment, passive immunization with immunoglobulin around area of wound, active immunization with inactivated virus

Question 13

• 80nm in diameter but up to 800-14,000 nm in length
• enveloped particles
• (-)ssRNA nonsegmented
• pleomorphic, filamentous appearance
• polyploidy
• include Ebola and Margburg viruses

Answer 13

filoviruses

Question 14

encodes for 3 different glycoproteins based on ORF1, ORF2, and transcriptional stutter

Answer 14

ebola virus

Question 15

ebola virus transmitted by?

Answer 15

body fluids, object such as needle contaminated with virus, or infected animals

Question 16

secretory protein of ebola?

Answer 16

need answer

Question 17

ebola hemorrhagic fever:

• incubation period?
• initial symptoms?
• hemorrhages?
• time between onset of symptoms and death?

Answer 17

• 3 to 21 days
• fever, chills, headache, n/v/d, can be confused with malaria or dengue; development of rash
• hemorrhages at conjunctiva, mucosal membranes of oral cavity, GI tract skin
• 7-14 days, death usually due to shock

Question 18

role of Ebola virus proteins in pathogenesis:

• _______ is known to cause cell death, endothelial cell activation and loss of barrier functions
• _____ may have anti inflammatory properties

Answer 18

G1/2 glycoprotein

sGP