Paramyxovirus

Question 1

What are the three genera within the paramyxoviridae?

Answer 1

Morbillivirus, Paramyxovirus, and Pneumovirus

Question 2

What virus is contained within the genus Morbillivirus?

Answer 2

Measles virus

Question 3

What viruses are contained within the genus paramyxovirus?

Answer 3

Parainfluenzaa viruses I-IV and Mumps

Question 4

What viruses are contained within the Pneumovirus genus?

Answer 4

Respiratory syncytial virus and Metapneumovirus

Question 5

What is the host cell receptor for measles?

Answer 5

CD46 is the host receptor for measles virus that is on all nucleated cells. Others include SLAM (CD150) on T cells and B cells and nectin 4 on epithelial cells.

Question 6

What is a consequence of measles infecting B and T cells?

Answer 6

It causes immunosuppression, which can lead to secondary bacterial infections.

Question 7

How many serotypes are there of measles virus?

Answer 7

There is only one serotype of measles virus. This makes it a good candidate for eradication.

Question 8

What cell type does measles virus initially infect?

Answer 8

Epithelial cells of the upper respiratory tract.

Question 9

How else can measles cause immunosuppression?

Answer 9

It inhibits IL-12 production, interfering with normal TH1 differentiation and macrophage recruitment of NK cells.

Question 10

When does the prodrome phase symptoms of measles usually occur?

Answer 10

Before the appearance of the morbilliform rash. This means that people usually feel better once the rash itself appears.

Question 11

What is the recommended schedule for the MMR vaccine?

Answer 11

A routine vaccination at 12 months followed by a booster at 4-6 years of age is recommended.

Question 12

What type of vaccine is the MMR vaccine?

Answer 12

It is a live attenuated vaccine. Because of this there is a small chance that it can cause complications in those who are immunocompromised

Question 13

What is the success rate for the MMR vaccine?

Answer 13

Over 95% of people will have lifelong immunity.

Question 14

What percentage of the population does measles immunity have to drop to before herd immunity begins to fail?

Answer 14

Once the number of people immunized against measles falls to or below 93%, an outbreak can occur.

Question 15

What type of rash is caused by measles?

Answer 15

A maculopapular rash. This consists of a papule resting on top of a red bed.

Question 16

How does the measles rash start and spread?

Answer 16

It begins in the neck and head and then begins to move centrifugally to the trunk and extremities.

Question 17

What causes the rash seen in measles?

Answer 17

CD8 T cells attacking virus infected endothelial cells of capillaries.

Question 18

What is exanthem?

Answer 18

An external rash.

Question 19

What is enanthem?

Answer 19

An internal rash.

Question 20

What kind of enanthem is characteristic of measles?

Answer 20

Koplik’s spots. They are white lesions that appear on the buccal mucosa (opposite the lower 1st & 2nd molars)

Question 21

What are macules?

Answer 21

Macules are small, circumscribed changes in skin color that are neither raised or depressed.

Question 22

What are papules?

Answer 22

Papules are circumscribed solid elevations on the skin with no visible fluid.

Question 23

What time period do the prodromal symptoms occupy?

Answer 23

The first 2-3 days.

Question 24

What are the prodromal symptoms?

Answer 24

Cough, Conjunctivitis, and Coryza (head cold symptoms) (CCC). There is also the appearance of koplik’s spots.

Question 25

What follows the prodromal symptoms?

Answer 25

The next 3-4 days are occupied by rash and recovery.

Question 26

What is prodrome defined as?

Answer 26

A prodrome is a set of early symptoms indicating the onset of an attack or disease. Symptoms that are less specific and precede the defining characteristics of the disease.