Viral Infections: Polio Virus

Question 1

What kind of viral infection is polio?

Answer 1

Acute systemic viral infection

Question 2

What is the level of severity of polio virus infection?

Answer 2

Mild / self-limiting to severe / paralytic in small % of the cases

Question 3

Described the structure of polio virus. Which genus does it belong to?

Answer 3

> Spherical, unencapsulated RNA virus

> Enterovirus genus

Question 4

How many serotypes does polio have?

Answer 4

3 serotypes

Question 5

A.k.a. killed vaccine

Answer 5

Salk

Question 6

Salk is a.k.a

Answer 6

Killed vaccine

Question 7

Sabin is a.k.a.

Answer 7

Live attenuated oral vaccine

Question 8

Live attenuated oral vaccine is a.k.a

Answer 8

Sabin

Question 9

Salk / killed vaccine / inactivated vaccine is recommended for?

Answer 9

Recommended in LOW prevalence areas and protects against all 3 serotypes of polio

Question 10

How is polio virus transmitted?

Answer 10

> Fecal-oral transmission (because it is an enterovirus, it is a GIT virus)

> Binds CD155 (epithelial adhesion molecule) to enter the cell

Question 11

Where does polio virus replicate?

Answer 11

In pharynx and gut, then spreads into tonsils and Peyer patches in the GIT

Question 12

As the polio virus spreads through the lymphatics, to nodes, then goes to hematogenous spread, the patient will present with what?

Answer 12

> Transient viremia

> Fever

Question 13

CNS manifestations in polio occur in ___ in 100 infections

Answer 13

1 in 100

Question 14

Type of poliomyelitis where there is paralysis usually in these patients due to the denervation paralysis of affected areas. Usually we’ll see the affected muscles shrink.

Answer 14

Spinal poliomyelitis

Question 15

Type of poliomyelitis which infects the brainstem

Answer 15

Bulbar poliomyelitis

Question 16

Oral polio vaccine can mutate back to wild. True or False? WHY?

Answer 16

> True. This is the type of infectious form which can cause outbreaks.

> It is not recommended in places with low incidence / prevalence since there’s a risk of reverting back into wild type.

> Since it is a live vaccine, it is going to help spread immunity faster because if the vaccine type virus sheds and other people get infected with it, they become immunized. Since there is risk of reverting back to wild type, there needs to be a wide coverage of the vaccine so that people are adequately protected.

Question 17

Diagnosis for polio

Answer 17

> Viral culture

> PCR

> Serology / Antibodies