E2- Viral infections of the CNS

Question 1

What is the destruction of motor neurons in spinal cord that results in asymmetric flaccid paralysis?

Answer 1

Poliomyelitis

Question 2

What are the types of clinical syndromes associated with Polio virus?

Answer 2

1. Inapparent infection
2. Abortive illness
3. Nonparalytic poliomyelitis
4. Paralytic Poliomyelitis
5. Post poli syndrome

Question 3

What viral infection causes flaccid paralysis from lower

motor neuron damage in less than 1% of infected individuals?

Answer 3

Polio virus

Parylytic poliomyelitis

Question 4

What viral infection causes muscle weakness, pain, and fatigue 30 or more yrs after infection?

Answer 4

Post polio syndrome in paralyzed polio patients

Question 5

What causes post polio syndrome?

Answer 5

Remaining motor units of CNS now react to over use and fail

Question 6

How is polio virus prevented?

Answer 6

Inactivated polio vaccine (IPV)
Live polio vaccine
Now called EIPV

Question 7

Inactivated polio vaccine (IPV) prevents what?

Answer 7

Disease (paralysis), not infection

Question 8

What type of vaccine is the Live polio vaccine?

Answer 8

Trivalent oral polio vaccine, OPV (Sabin)

Question 9

What polio vaccine is used in the US?

Answer 9

Only IPV is employed in US (inactivated polio vaccine)

Question 10

Last case of paralytic disease in America caused by a ___ virus was decades ago.

Answer 10

Wildtype

Question 11

What type of virus is polio virus?

Answer 11

Picorna virus (3 antigenic types)

Question 12

Why is the live polio vaccine (OPV) not given in the US?

Answer 12

Back mutation to wild type
Risk of VAPP (vaccine associated paralytic poliomyelitis) associated with use of the oral vaccine is considered to be unacceptable
If you had not vaccinated them at all, they would probably have never been infected/paralyzed

Question 13

Arboviruses use what as vectors?

Answer 13

Athropods-borne viruses
Mosquitos and ticks
Birds and small mammals

Question 14

What are the three groups of arboviruses?

Answer 14

Togaviridae group
Flaviviridae group
Bunyaviridae

Question 15

What are rare strains of poliovirus that have genetically mutated from the strain contained in the oral polio vaccine?

Answer 15

Circulating vaccine-derived poliviruses (cVDPVs)

Question 16

What causes St. Louis encephalitis, West Nile virus, Dengue virus, and yellow fever?

Answer 16

Flaviviridae group of arboviruses

Question 17

What causes California encephalitis virus?

Answer 17

Bunyaviridae group of arboviruses

Question 18

What are the general clinical manifestations of Arboviruses?

Answer 18

Abrupt onset of fever, HA, vertigo, photophobia, N/V

Confusion and personality changes, focal or general seizures

Question 19

How is arbovirus dx?

Answer 19

Tests for IgM antibody with CSF or serum (*MAC-ELISA)

Question 20

What may induce long-lasting positive IgM titers when testing for arboviruses?

Answer 20

Vaccination against Yellow fever and/or Japanese encephalitis

Question 21

How is arbovirus infection prevention?

Answer 21

Interrupt chain of transmission (mosquitoes)
Eradication of vector
Avoidance of exposure
(Window screens, Insect repellents)
Immunization of nonhuman amplifying hosts (Horses)

Question 22

How is Zika virus spread?

Answer 22

Mosquitoes and STI (months after infection; male could infect female leading to birth defects)

Question 23

This the major concern with Zika virus?

Answer 23

Teratogenic potential, also linked to GBS

Question 24

How is Zika virus dx?

Answer 24

Nucleic acid test (PCR) and MAC ELISA

Question 25

What does Zika have antigenic cross-reaction with?

Answer 25

Flaviviruses such as Dengue

Question 26

What have the majority of Zika viruses been associated with?

Answer 26

Travel

Question 27

Rabies is considered invariably ____ once symptoms are overt

Answer 27

Fatal

Question 28

What is seen in the excitatory phase of rabies infection?

Answer 28

Furious in dogs Anxiety Apprehension hydrophobia (humans only) Increased salivation/foaming at the mouth from not swollowing

Question 29

What phase of rabies infection causes coma, hypotension, and death?

Answer 29

Paralytic phase

Question 30

Exposure to or bite from what animals is sufficient to initiate post exposure prophylaxis?

Answer 30

Skunk, fox, raccoon, or bat* | Kill and examine animal immediately

Question 31

Exposure to or bite from what animals requires no action because they are rarely infected?

Answer 31

Rodents and rabbits

Question 32

What type of virus is rabies?

Answer 32

Rhabdovirus

Question 33

What is pathognomonic for rabies?

Answer 33

Negri body

Question 34

Retrospective study has revealed the majority of human cases since 1990 have been ____, not linked to bites, but simple contact

Answer 34

Cryptic

Question 35

What is the tx for clinically overt rabies?

Answer 35

There is no therapy for clinically overt rabies – the “Milwaukee” protocol has failed as often as it has succeeded

Question 36

How is rabies prevented?

Answer 36

(1) avoidance of exposure (2) prophylactic vaccination of companion and herd animals, and (3) immunization after exposure (post exposure prophylaxis consisting of vaccine and hyperimmune serum)