SHORS - POLIO MOD8

1. Which of the following is not a characteristic of enteroviruses?

A) Oral–fecal transmission

B) Icosahedral capsid

C) (+) sense RNA

D) Enveloped

D — Enveloped

2. Which of the following treatments would inactivate polio?

A) Protease

B) Chloroform

C) pH less than 3

D) Aldehyde

D — Aldehyde

3. Which virus is primarily associated with meningitis and encephalitis?

A) Echovirus type 11

B) Poliovirus

C) Coxsackievirus B

D) Enterovirus D68

A — Echovirus type 11

4. What would happen if the RNA genome of poliovirus was transfected into mouse cells?

A) Nothing

B) The RNA genome would be converted into DNA.

C) The RNA genome would be converted from negative-sense to positive-sense.

D) The RNA genome would be translated by host ribosomes into a polyprotein.

D — The RNA genome would be translated by host ribosomes into a polyprotein.

5. Which form of poliomyelitis results from viral invasion of the motor neurons of the anterior horn and is characterized by paralysis on one side of the body?

A) Bulbar

B) Subclinical

C) Spinal

D) Bulbospinal

C — Spinal

6. A poliovirus with a mutated VPg would be unable to:

A) cleave the viral polyprotein.

B) initiate replication.

C) attach to host cells.

D) uncoat.

B — initiate replication.

7. Which of the following is not a characteristic of the Sabin vaccine?

A) Contains three serotypes of vaccine virus

B) Requires booster vaccinations

C) Sheds in stool weeks following vaccination

D) Can cause vaccine-associated paralytic polio

B — Requires booster vaccinations

8. Which viral infection may cause earaches and sinusitis and exacerbate asthma?

A) Coxsackie virus

B) Rhinovirus

C) Enterovirus

D) Echovirus

B — Rhinovirus

9. Which country accounted for the majority of wild-type polio cases in 2014 and 2015?

A) India

B) Congo

C) Pakistan

D) Nigeria

C — Pakistan

10. Where did the first major outbreak of poliovirus in the United States occur?

A) Vermont

B) New York

C) Texas

D) Florida

A — Vermont

1. True or False? Humans are the sole natural hosts for the poliovirus.

FALSE

2. True or False? The majority of poliovirus infections are asymptomatic.

TRUE

3. True or False? The Sabin vaccine is no longer readily available in the United States.

TRUE

4. True or False? Infants are the most efficient transmitters of poliovirus infection.

TRUE

5. True or False? ELISA is the most sensitive method to diagnose poliomyelitis.

FALSE

1. Following ingestion, the main sites of poliovirus replication include the tonsils and ________.

Peyer’s patches

2. ________ are used to assist the breathing of patients afflicted with bulbar poliomyelitis.

Iron lungs
Alternative ans: Drinker respirators

3. __________ proposed that polio victims be treated with the movement and stretching of paralyzed muscles rather than the use of immobilizing leg braces.

Sister Kenny

4. The main clinical manifestation of paralytic polio is __________, characterized by extreme weakness of muscles and loss of muscle tone.

flaccid paralysis

5. Polioviruses are incapable of infecting mouse cells because they lack the poliovirus receptor, also known as ______.

CD155

1. Describe the Cutter incident and its impact on vaccine manufacturing.

The “Cutter incident” is a pharmaceutical disaster in which certain lots of the Salk poliovirus vaccine produced by Cutter laboratories were not inactivated appropriately. Consequently, several thousand people were exposed to live poliovirus, with some developing disease. As a result of this incident, the government established requirements for the manufacture and safety testing of vaccines.

2. Explain why the Sabin vaccine is no longer used in the United States.

The Sabin vaccine is a live, attenuated vaccine. In rare cases the vaccine actually causes poliomyelitis, termed vaccine-associated paralytic polio (VAPP). To reduce the occurrence of VAPP in the United States, the CDC recommended that killed Salk vaccine be used exclusively.

3. Describe the public health concern posed by enterovirus D68.

Enteroviruses normally cause asymptomatic or self-limiting infections in children. However, the 2014 outbreak of enterovirus D68 was/is a public health concern because this virus causes severe respiratory illness and breathing difficulties in children. Further, a cluster of children in Colorado developed a mysterious polio-like illness after contracting the virus.

4. Explain why polio has yet to be eradicated.

Polio has been difficult to eradicate because it remains a problem in developing countries due to poor sanitation and polluted drinking water, weak public health services, and disruption of mass vaccination efforts due to political unrest or conflict. Further, distrust in vaccination has led to low vaccination rates in some areas in the world, which has led to an increase in the number of vaccine-associated poliomyelitis.

5. List the three forms of paralytic polio.

Spinal, bulbar, and bulbospinal

6. Briefly explain how poliomyelitis is diagnosed.

Stool samples collected from patients suspected of being infected are cultured with human or monkey kidney cells. The presence of poliovirus is indicated by the microscopic observation of CPE. The serotype of the virus is determined using neutralization assays.

7. Detail the properties of enteroviruses that contribute to their stability in the environment.

Enteroviruses are capable of surviving the harsh environment of the gastrointestinal tract because they are unaffected by pH levels lower than 3 and are resistant to proteases. Also, because enterovirus particles are naked, they are resistant to several disinfectants and can survive long-term in water.

8. List the nonpolio enteroviruses that are of public health concern.

The enteroviruses known to infect humans and cause disease are Coxsackie viruses, rhinoviruses, enteroviruses, and echoviruses.

1. Docking site for the 40S ribosomal subunit

IRES

2. Initiation of viral replication

VPg

3. Capsid protein

VP1

4. Protease that cleaves the polyprotein

2A

5. Group A Coxsackie virus

Mouth blisters or sores

6. Echovirus

Encephalitis

7. Enterovirus D68

Paralysis

8. Rhinovirus

Exacerbate wheezing