Measles Flashcards
How is a fetus protected from measles?
IgG transplacental antibody transit from mother
How long does transplacental IgG transfer protect an infant after birth?
Approximately 9 months.
In an outbreak what can be given to non-immune household contacts and what is the timeframe to give it?
The vaccine, within 72 hours of First Contact.[CDCM - There is some evidence that a single dose of MMR vaccine, when given to an unvaccinated person within 72 hours of first contact with an infectious person, may reduce the risk of developing disease.]
In an outbreak what can be given to non-immune pregnant women and infants for prophylaxis?
Immunoglobulin if pre-prodromal
What is the R0 for the measles virus?
12-18
MoH, Imms Handbook 2020
In 2017 what status was verified in New Zealand by the WHO?
Having eliminated endemic measles.
How long after measles vaccination is IgM detected?
1-2 months
What is the incubation period for measles from exposure to a) fever, and b) rash?
Typically: 10 days till onset of fever; 14 days till onset of rash
What is the survival time outside the body?
2 hours
What is the mode of transmission?
Airborne or by direct contact with nasal/throat secretions
When is the period of communicability?
5 days before to 5 days after appearance of rash.
What treatments are used with measles and what do they address?
a) symptomatic
b) vitA in hospital to reduce risk of fatality & eye complications
What are the symptoms of measles in the enanthem phase?
Koplik spots
What are the symptoms of measles in the exanthem phase?
Cephalocaudal maculopapular rash
State 4 genomic features of the measles virus from smallest to largest.
1) 16k bases,
2) single strand negative sense RNA,
3) 6 genes,
4) 24 genotypes
Which year was the most recent outbreak in New Zealand?
2019
Name the surface protein on measles that attahes to host cell receptors; and name 3 human receptor targets?
Hemagglutinin to either:
CD46 (all nucleated cells)
CD150/SLAM (B/T cells)
Nectin-4 (cellular adhesion molecule)
When is the MMR vaccine given in New Zealand?
12 months and 15 months
What is in the measles vaccine in New Zealand?
Live attenuated virus (Priorix from GSK)
How do outbreaks occur in New Zealand?
Large non-immunised population in children/adults.
Infectious arrivals.
Arrival of non-immune carriers after travel.
How effective is the MMR vaccine?
95% after dose 1
99% after dose 2
