Lecture 8: Measles, Mumps, Rubella

Question 1

Measles virus
Capsid:
Genome and shape:
Envelope:

Answer 1

Helical
(-) ssRNA, linear
Yes

Question 2

Which virus is one of the classical childhood exanthems

Answer 2

Measles
Exanthems = rash with fever

Question 3

Measles transmission
-how?
-contagious?

Answer 3

-highly contagious
-aerosol droplets (shedding before & after onset of symptoms)
-ONLY infects humans

Question 4

Measles Clinical symptoms

Answer 4

-CCC (cough, Coryza, conjunctivitis) conjunctivitis behind in prodromal phase
-high fever
-Koplik’s spots pathognomonic for measles = buccal mucosa opposite 1st and 2nd upper molars
-rash appears 2-3 days later
-contagious 4 days before rash appears until 4 days after rash disappears (spread virus before you even know you are sick)
-incubation period lasts 1-2 weeks

Question 5

Koplik’s spots
-what are they
-where are they found
-pathognomonic for what virus

Answer 5

“Grains of salt on a red halo”
-white lesions on erythematous base found on mucous membranes
-found especially on the bucal mucosa opposite the 1st and 2nd upper molars
Pathognomonic for Measles

Question 6

Maculopapular rash
-found with what virus?
-when do rash appears?
-contagious?

Answer 6

-Measles
Rash appears 2-3 days later
Contagious 4 days before rash appears, contagious 4 days after rash disappears
-rubella/3 day German measles
Begins on face then spreads to trunk then extremities
Before rash appears, petechiae on soft palate

Question 7

Complications for measles

Answer 7

-SSPE (subacute sclerosing panencephalitis) (neuro disorder)
-pneumonia (children)
-encephalitis (adults)
-Otitis media (middle ear infection)
-diarrhea

Question 8

Measles Diagnosis

Answer 8

-Koplik’s spots are pathognomonic
-ELISA = IgM
-RT-PCR (b/c RNA virus)

Question 9

Measles Treatment & Prevention
-what vitamin?

Answer 9

-MMR vaccine! (12-15 months, 4-6 yoa)
-vitamin A reduces disease severity in malnourished children
-no antivirals treatment available (obviiii we got the vaccine)

Question 10

Mumps virus
-capsid
-genome
-envelope

Answer 10

Spherical
(-) ssRNA,
Yes

Question 11

Mumps virus
-receptor
-antigen
-attachment for cell replication (1st step)

Answer 11

RECEPTOR
-sialic acid
ANTIGEN
-Hemagglutinin/Neuraminidase (HN are on the same spike vs. in influenza A where they are separated)
-Fusion Protein: facilitates cell fusion producing multinucleated giant cells

Question 12

Mumps transmission
-spread
-shed

Answer 12

Highly infectious
-spread by respiratory droplets, saliva, fomites
-shed in respiratory secretions during pre-clinical period and urine after 14 days onset

Question 13

clinical presentations for mumps

Answer 13

-Parotitis (painful + fever) mostly bilateral
-Parotid glands = salivary glands
-most common feature of the disease

Question 14

Complications for mumps

Answer 14

-males = orchitis and epidiymoorchitis
-females = oophoritis
-meningitis
-encephalitis

Question 15

Mumps diagnosis

Answer 15

-RT-PCR (b/c RNA virus) … w/n the first 3 days of symptoms
-ELISA = igM … after the first 3 days of symptoms

Question 16

Treatment and prevention for mumps

Answer 16

-MMR vaccine ( 1st dose: 12-15 moa. 2nd dose: 4-6 yoa)

Question 17

Rubella/German measles
-capsid
-genome
-envelope

Answer 17

Icosahedral
(+) ssRNA
Yes envelope

Question 18

Transmission for rubella

Answer 18

-aerosol droplets
-VERTICAL TRANSMISSION
RUBELLA IS A DANGEROUS TERATOGEN
Teratogen = increase risk of birth defects in a developing fetus/embryo

Question 19

Rubella clinical presentation

Answer 19

-Maculopapular rash (begins on face, then spreads to trunk, then to extremities) NONE AT PALMS/SOLES
-before rash appears, petechiae on the soft palate can be observed (non-specific symptom)

Question 20

Rubella pathogenesis
-also known as

Answer 20

German 3-day measles
-multiplies asymptomatically in the URT
-then lymphadenopathy
-viremia
-faint rash appears first on neck and face
-resolves in 3 days (life-long immunity)
by the time the virus is in the body… b-cells have already produced anti-bodies. Therefore once the body is showing symptoms, the virus ends quickly

Question 21

Congenital rubella syndrome (CRS)

Answer 21

-microcephaly
-PDA - patent ductus arteriosus (heart)
-cataracts
a condition that occurs to the baby when the mother has rubella

Question 22

Rubella diagnosis

Answer 22

-Elisa - igM
-RT-PCR (b/c RNA virus) (can be able to detect vertical transmission)
IgM = first antibody produced during infection

Question 23

Rubella treatment and prevention

Answer 23

MMR vaccine
All women of childbearing age should be vaccinated before pregnancy

Question 24

Koliocytes vs. Koplik’s spots

Answer 24

Koliocytes = Pathognomic for HPV
=clear holes surrounding shrunken nuclei
Kopliks spots = pathognomonic for measles
= buccal mucosa opposite 1st and 2nd upper molars
=white lesions on erythematous base found on mucous membranes