Lecture 20

Question 1

What family does measles belong to?

Answer 1

Measles belongs to the paramyxoviridae family.

Question 2

What are some of measles characteristics?

Answer 2

Measles virus is a single stranded, RNA virus with a helical nucleocapsid, enveloped and has one serotype. Two membrane envelope proteins are important in pathogenesis which are F (fusion) protein and the H (hemagglutinin) protein.

Question 3

How is measles spread and what is its incubation time?

Answer 3

Measles spreads via respiratory droplets and has an incubation time of 3-7 days.

Question 4

What are some common symptoms of measles?

Answer 4

Common symptoms of measles include 3 C’s (cough, conjunctiva, coryza), Koplix spots, four days fever, and maculopapular rash.

Question 5

Describe measles pathogenesis

Answer 5

1. Enters the body and replicates in the respiratory epithelium, leading to viremia and dissemination to lymphoid tissues.
   
   2. The H protein is responsible for the virus’s attachment to host cells, while the F protein mediates viral penetration and fusion with the host cell membrane.
   3. Also infects immune cells, leading to immune suppression and making the host more susceptible to secondary infections.
   4. Prodromal phase shows 3 C’s, fever, Koplik spots.

Question 6

What are Kopliks spots?

Answer 6

Koplik spots are a common symptom of measles which involve the buccal and labial mucosa. They appear as irregular, patchy erythema with tiny central white specks.

Question 7

What is mumps and how is it transmitted?

Answer 7

Mumps is part of the paramyxovirus family and is an acute viral disease of humans most commonly affecting children and young adults. Mumps is transmitted via respiratory droplets.

Question 8

What is the pathogenesis of mumps?

Answer 8

Mumps is transmitted via respiratory droplets, infecting the epithelial cells of the upper respiratory tract. The virus disseminates to the lymph nodes, where it replicates and causes lymphadenopathy. The virus then enters the bloodstream and spreads to other organs, including the pancreas, testes, and ovaries. In the salivary glands, the virus infects the glandular cells, causing inflammation and swelling of the gland.

Question 9

What family is rubella?

Answer 9

Rubella is in the togavirus family.

Question 10

what is rubella incubation period?

Answer 10

Rubella has an incubation period of 14 days.

Question 11

How is rubella transmitted and what are some common symptoms?

Answer 11

Rubella spreads via respiratory droplets. Common symptoms of rubella include maculopapular rash and arthralgia, which is a problem in adult women.

Question 12

What is congenital rubella syndrome?

Answer 12

Congenital rubella syndrome happens when the Rubella virus crosses the placenta to cause destruction of some fetal cells and disruption of cell division. This can result in birth defects including deafness, blindness, heart defects, and developmental delays.

Question 13

What is the MMR vaccine strategy and when is it administered?

Answer 13

The MMR vaccine strategy involves a two-dose vaccination strategy with Trivalent MMR vaccine. MMR1 is administered by a GP at 12 months of age and MMR2 is administered at 4-5 years of age by HSE vaccination teams at primary school.

Question 14

What is a severe symptom of measles?

Answer 14

Encephalitis

Question 15

What is the incubation time for mumps?

Answer 15

18-21 day

Question 16

What age is most affected by rubella?

Answer 16

4-9 years old

Question 17

What is the pathogenesis of rubella?

Answer 17

1. Rubella enters via the respiratory tract and replicates in the nasopharynx and regional lymph nodes, leading to a primary viremia, which occurs 5-7 days after exposure.
   
   2. The virus can then spread to other organs, including the spleen, liver, and bone marrow, leading to a secondary viremia.