CNS enteroviruses

Question 1

2 symptoms of poliomyelitis?

2 sites you isolate the virus from

How do you determine the virus type?

Answer 1

Fever and ASYMMETRIC flaccid paralysis.

Isolate from fecal matter or respiratory secretions (pharyngeal).

RT-PCR.

Question 2

4 descriptions of the Polio virus

Answer 2

1) Picorna virus
2) ssRNA
3) Noneveloped (no lipids)
4) Acid stable

Question 3

How many antigenic types of polio are there?

Answer 3

3

Question 4

T or F? Humans are the sole natural host of Polio.

3 methods of infections

Answer 4

True

1) direct 2) indirect Fecal2Oral route 3) direct contact with infected respiratory secretions.

Question 5

How does the polio virus enter? and What are the 2 places it multiplies?

Answer 5

Enters via GI tract, via M cells.

Multiplies in the Pharynx and the Small intestine.

Question 6

3 areas of infection by polio?

Answer 6

1) Anterior horn cells of spinal cord.
2) Brain stem with respiratory paralysis (bulbar form)
3) Motor cortex of brain (rare).

Question 7

Two routes of virus entry into CNS?

Answer 7

1) From the blood or via direct retrograde axonal flow.

Question 8

The polio virus genome is a ____ sense and functions _____ as mRNA.

Answer 8

Positive sense; Directly as mRNA.

Question 9

4 Clinical syndromes of Polio?

Answer 9

1) Inapparent infection: most common, asymptomatic
2) Abortive illness: fever, malaise, recover spontaneously.
3) Nonparalytic poliomyelitis: Fever, malaise, stiff neck and back; 2-10 day duration. Recover spontaneously.
4) Paralytic poliomyelitis: flaccid paralysis with LMN damage; damages to nerves is permanent.

Question 10

Describe post polio syndrome

Answer 10

Muscular atrophy decades AFTER case of paralytic polio.

up to 25% of all paralyzed patients.

Question 11

_______ which is replicated in monkey cells to produce attenuated polio viruses can cause Malignant transformation of nonpermissive cells.

Another concern is PML (progressive multifocal leukoencephalopathy), causes_____.

Answer 11

SV40

Virus-induced lysis of oligodendrocytes.

Question 12

2 genera of Human picorna viruses

Answer 12

1) Enteroviruses- infect via gut

2) Rhinoviruses

Question 13

What are the 2 characteristics of picornaviridae? and what are the 2 viruses?

Answer 13

Small ss+RNA; Nonenveloped.

ECHO and Coxsackie.

Coxsackie: similar to polio in sturcture; different in RNA base sequence.
A= acute inflammation and necrosis of muscle fibers.
B= Focal degeneration of brain.

Question 14

Clinical manifestations of ECHO/ Coxsackie CNS infection in New born and Adults?

Answer 14

Newborn:
Sudden onset, URTI, Meningeal inflammation, Bulging anterior fontanelle.
Death by Hepatic Failure (ECHO); Myocarditis (Coxsackie).

Adults:
Fever, Headache, Nuchal rigidity.

Question 15

Which body site of isolation is the best link to the disease of ECHO or Coxsackie?

Answer 15

Nasopharynx

Question 16

Piccornaviridae
Infections are most common in the ________ & _________ in temperate zones.

They occur in _________ primarily.

Disease probability and severity are ____________ proportional to age.

____________ transmission.

Answer 16

Summer and fall

Young children

Inversely proportional

Fecal to oral.

Question 17

Describe the Lymphocytic Choriomeningitis Virus.

ssRNA, physical description; Where is replication.

Answer 17

2 ssRNA strand circles: 1 (-) strand; 1 (S) is ambisense.

Enveloped and studded with HOST ribosomes.

10x larger

Replication occurs in the cytoplasm.

Question 18

LCM infections tend to have a ________ -_______ predominance.

Which age groups?

Answer 18

Autumn-winter

ALL age groups.

Question 19

Diagnosis of LCM is with cases of suspected_________ and a history of exposure to _________.

Answer 19

Aseptic meningitis

Rodents.

Question 20

Definition of Poliomyelitis

Answer 20

Destruction of motor neurons in spinal cord with paralysis is most feared.