Picornaviruses

Question 1

Picornaviruses General Characteristics (3)

Answer 1

Small
Non-enveloped
ssRNA

Pico = small
rna = RNA

Question 2

Picornaviruses Two Main Groups

Answer 2

1- RHINOVIRUSES —> Replicate only in Respiratory tract —> Common cold

2- ENTEROVIRUSES —> Replicate in GI tract and/or Respiratory tract

Question 3

Rhinovirus Characteristic

Answer 3

Most common cause of COMMON COLD

Question 4

Rhinovirus Clinical Manifestations (8)

Answer 4

Fever
Sore throat
Runny nose and Nasal congestion
Sneezing 
Cough

Sometimes accompanied by:
1- Fatigue, muscle aches, muscle weakness
2- Headache
3- Loss of appetite

Question 5

Vaccine and Antiviral?

Answer 5

Antiviral —> PLECONARIL

Vaccine—> NO

Question 6

Enteroviruses Groups (5)

Answer 6

1- Polioviruses

2- Coxsackie A and B

3- Echoviruses

4- Enteroviruses (subtype 68-71)

5- Hepatitis A virus

Question 7

Can Enteroviruses spread other than fecal-oral route??

Answer 7

YES

Eyes, nose, mouth secretions (e.g. saliva, nasal mucus, or sputum), or blister fluid

Remember- they are in the respiratory tract also!!

Question 8

Enteroviruses comparison (7)

Answer 8

Asymptomatic infection? All

Meningitis? All

Paralysis? No- Enteroviruses (other)

Febrile Exanthema? No- Poliovirus

Acute Respiratory Disease? No- Poliovirus

Myocarditis? No- Poliovirus and Enteroviruses (other)

Orchitis? No- Poliovirus, Coxsackie A, Enteroviruses (other)

Question 9

Enteroviruses- Skin (1)

Answer 9

Coxsackievirus A

Question 10

Enteroviruses- Muscles (3)

Answer 10

Echovirus

Coxsackie A and B

Question 11

Enteroviruses- Brain/spinal cord (3)

Answer 11

Poliovirus

Coxsackie A and B

Question 12

Enteroviruses- Meninges (4)

Answer 12

Poliovirus

Echoviruses

Coxsackie A and B

Question 13

Asymptomatic Polio Infection (3)

Answer 13

When replication of virus restricted to GI tract

Most common

Results in life-long immunity

Question 14

Abortive poliomyelitis (Mild Illness) (3)

Answer 14

Occurs in infants in undeveloped nations, where poor sanitation

Patient exhibit febrile disease in first week which may be accompanied by general malaise, vomiting, headache, and sore throat

5% of cases

Question 15

Non-paralytic Poliomyelitis (3)

Answer 15

Three or four days later, patient exhibits stiff neck and vomiting —> similar to aseptic meningitis

Virus now progressed to brain and affected meninges

Recovery in 1 week

Question 16

Paralytic Poliomyelitis (2)

Answer 16

About 4 days, virus spread from blood to anterior horn cells of spinal cord and to motor cortex of brain

Degree of paralysis depends on which neurons affected and amount of damage they sustain

Question 17

Types of Paralysis (3)

Answer 17

1- Spinal Paralysis (affects spine) —> One or both limbs may be affected leading to Flaccid paralysis

2- Bulbar Paralysis (affects brain stem) —> Cranial nerves affected leading to muscle paralysis of tongue, lips, palate, pharynx, and larynx

3- Bulbospinal paralysis (affects spine and brain stem)

Question 18

Poliovirus vaccines

Answer 18

1- Inactivated vaccine (Salk)
- Injection

2- Live attenuated vaccine (Sabin)
- Oral

Question 19

Enteroviruses Meningitis (4)

Answer 19

Most COMMON type of viral meningitis

Coxsackie A + B and Echoviruses

Summer months

No vaccine- most patients recover on their own

Question 20

Another name for Viral Meningitis

Answer 20

Aseptic Meningitis

Question 21

What is the most common cause of Myocarditis?

Answer 21

Viral infections

Question 22

Which Enteroviruses cause Carditis?

Answer 22

Coxsackie A+B and Echoviruses

Question 23

Hand, Foot, and Mouth Disease (4)

Answer 23

Caused by Coxsackie A and Echoviruses

Common and highly contagious self-limiting viral infection

Mainly affects infants and children

Begins with Fever followed by Maculopapular Rash that may involve skin of hands, feet, and oral cavity (goes away in a week)

Question 24

Herpangina (4)

Answer 24

Mouth blisters

In summer, mostly affects children

Mild, self-limiting

Coxsackie A, Coxsackie B, Echoviruses

Question 25

Treatment (3)

Answer 25

Antibody preparations resulted in stabilization of conditions

PLECONARIL is an ANTIVIRAL DRUG active against ENTEROVIRUSES and RHINOVIRUS

NO VACCINE to prevent ENTEROVIRUSES infections (apart from POLIOVIRUS)