MCQs on Polio Virus

Polio is a highly contagious virus that can cause paralysis of the spinal cord and brainstem. It primarily affects children under the age of five. Polio cases peaked in the United States in 1952, with 57,623 cases reported. The United States has been polio-free since 1979, thanks to the Polio Vaccination Assistance Act. Poliovirus (WPV) is divided into three types: type 1, type 2, and type 3. In order to avoid polio, people must be vaccinated against all three forms of virus, and the best protection is polio immunisation. Poliomyelitis is another name for polio. It is a viral disease that causes paralysis or muscle weakness in specific parts of the body by destroying nerve cells in the spinal cord. It is a contagious nerve system disease caused by the Picornaviridae poliovirus family.

1.  The poliovirus infection is spread through

a) breastfeeding

b) faecal-oral route

c) placental route

d) sexual route

Answer: b

Clarification: The poliovirus infection is spread through the fecal-oral route and the period of incubation is usually 1-2 weeks. The systemic symptoms include headache, fever, nausea, vomiting and myalgia.

2. Which of the following complications occur during the infection of poliovirus?

a) Respiratory failure

b) Airways obstruction

c) Kidney failure

d) ANS involvement

Answer: c

Clarification: The complications that occur during the infection of poliovirus are respiratory failure, obstruction of airways, and the involvement of the autonomic nervous system. Kidney failure does not occur due to poliovirus infection.

3. Which of the following is not the laboratory diagnosis of poliovirus?

a) RNA in the fecal sample

b) IgM antibodies in sera

c) IgG antibodies in sera.

d) IgA antibodies in sera

Answer: d

Clarification: The laboratory diagnosis of poliovirus includes the demonstration of poliovirus in throat swab or the fecal sample collected in the acute phase of the disease, viral RNA in the fecal sample, and poliovirus IgM antibodies or IgG antibody rise in paired sera.

4. Which of the following causes the paralysis of respiratory and pharyngeal muscles?

a) Bulbar poliomyelitis

b) Asthma

c) Polyradiculitis

d) COPD

Answer: a

Clarification: Bulbar poliomyelitis occurs in about 10% of all patients with paralysis. This may occur as a mixed bulbospinal form and this localization may lead to the involvement of cranial nerves with paralysis of pharyngeal muscles and dysphagia, and respiratory muscles followed by dyspnea.

5. Which of the following is called Guillain-Barre syndrome?

a) Asthma

b) Polyradiculitis

c) Heart failure

d) ParalysisAnswer b

Clarification: Polyradiculitis is also known as Guillain-Barre syndrome, where the pareses are ascending and symmetrical combined with a variety of sensory disturbances. The cerebrospinal fluid (CSF) shows a high protein content with no or only a slight increase in cell count.

6. Which of the following occurs during the acute stages of poliovirus infection?

a) Encephalitis

b) Post-poliomyelitis syndrome.

c) Asthma

d) Ischemic stroke

Answer: a

Encephalitis and myocarditis may occur during the acute stages of the poliovirus infection. Post poliomyelitis syndrome is observed in some 25% of survivors of paralytic poliomyelitis. They may also develop new weakness, pain, and fatigue

7.  he genome of poliovirus is

a) ssDNA

b) ssRNA

c) dsRNA

d) dsDNA

Answer: b

Clarification: The poliovirus consists of single-stranded RNA of positive polarity (mRNA) within a protein shell (capsid) composed of 60 capsomeres. The capsid is built up of four proteins and the virion is naked and has a diameter of 28nm

8. Polioviruses are

a) resistant to lipid solvents

b) resistant to protein solvents

c) unstable at pH values between 3-9

d) infectious for a shorter period in children

Answer a

Clarification: Polioviruses are resistant to lipid solvents and rather slowly inactivated at room temperature. They are stable at pH values between 3-9 and are infectious for a longer period in children than adults.

9. Which of the following is the most widely used vaccine for the prevention of poliomyelitis?

a) OPV

b) MMR

c) COD d) POR

Answer a

Clarification: OPV is the most widely used vaccine for the prevention of poliomyelitis. It induces intestinal immunity due to the production of secretory IgA. This is important for the inhibition of virus replication in the gut.

10. VP3 is a capsid protein.

a) True

b) False

Answer a

Clarification: VP3 is a capsid protein. The capsid is built mainly of four proteins: VP1, VP2, VP3, VP4. The virus replication is initiated by RNA transcription into negative strands to act as templates for new viral RNAS.

11. IPV is an inactivated virus vaccine.

a) True.

b) False

Answer a

Clarification: IPV is an inactivated virus vaccine and was the first vaccine used against poliomyelitis. It is administered. parenterally and contains three types of poliovirus inactivated by formaldehyde.

12. In 1955, the person who invented the Polio vaccine was

a) Hiram Maxim

b) Theodore Roosevelt

c) Jonas Salk

d) Joseph Stalin

Answer: c

13. Pick the correct statement regarding vaccines of Polio

a) Salk is an inactivated polio vaccine

b) Sabin is live attenuated polio vaccine

c) Salk and Sabin are polio vaccines

d) All the above are correct

Answer: c

Explanation: Salk and Sabin are polio vaccines. These polio vaccines are made with a killed virus and the Sabin vaccine, made with a live but weakened, or attenuated, virus.

14. Which serious ailment does the Poliovirus cause all over the world?

a) mental retarded ness

b) brain haemorrhage

c) paralysis

d) poliomyelitis

Answer: d

Explanation:

Polio, or poliomyelitis, is a disabling and life-threatening disease caused by the poliovirus. The virus spreads from person to person and can infect a person’s spinal cord, causing paralysis (can’t move parts of the body).

15. For the very first time, this virus was synthesized in the form of non-living crystals

a) Bacteriophage

b) Tobacco mosaic virus

c) Flu Virus

d) Pox virus

Answer: b

Explanation:

In 1935 tobacco mosaic virus became the first virus to be crystallised; in 1955 the poliomyelitis virus was crystallised.