Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Virology 2 > Question from S 10 > Flashcards

Question from S 10 Flashcards

1
Q

Official exam question - will be on 2024 exam

12 month old child presents to paeds assessment unit with 4 day history of fever, coryza, SOB, inflamed pharynx and conjunctivita, maculopapular rash

What 3 tests would you send?

A

Oral fluid swab -
- Rubella IgM/ IgG/ RNA
- Measles IgM/ IgG/ RNA

Nose/throat combination swab in VTM
- extended viral respiratory PCR

Clotted blood sample for serology
- Rubella IgM/ IgG
- Measles IgM/ IgG
- Parvo B19 IgM/ IgG
- CMV IgM/ IgG
- EBV IgM/ IgG

Consider if travel history:
Dengue, Zika, Chikungunya

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

exam question - will be on exam

Measles RNA testing

What is the target of RNA testing?

A

Measles H gene - haemagglutinin

Wild-type measles viruses have been divided into eight clades containing 24 genotypes based on the nucleotide sequences of their hemagglutinin (H) and nucleoprotein (N) genes, which are the most variable genes in the viral genome.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

exam question - will be on exam

Case 1
IgG 5
C/O 13

IgM 3.9
C/O >1

Oral fluid swab H gene PCR
CT 26
C/O 35

MS2 Bacteriophage DNA
CT 24
C/O 35

Human Ribonuclease P gene
CT 23
C/O 35

What is the importance of MS2 bacteriophage

A

MS2 bacteriophage DNA is used to spike the sample, and act as an internal control.

It ensures there is efficient nucleic acid extraction, and no PCR inhibition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

exam question - will be on exam

Case 1
IgG 5
C/O 13

IgM 3.9
C/O >1

Oral fluid swab H gene PCR
CT 26
C/O 35

MS2 Bacteriophage DNA
CT 24
C/O 35

Human Ribonuclease P gene
CT 23
C/O 35

What is the importance of Human Ribonuclease P gene

A

Human Ribonuclease P gene is a host target. This is used to control for adequate host material in the initial sample

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

exam question - will be on exam

Case 1
IgG 5
C/O 13

IgM 3.9
C/O >1

Oral fluid swab H gene PCR
CT 26
C/O 35

MS2 Bacteriophage DNA
CT 24
C/O 35

Human Ribonuclease P gene
CT 23
C/O 35

What are the possible clinical interpretations of these results?

A

MS2 Bacteriophage detected - passed
Human Ribonuclease P detected - passed

controls accepted

IgM detected
IgG not detected
RNA detected

consistent with an acute Measles infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Measles definitely be on exam

Case 1
IgG 5
C/O 13

IgM 3.9
C/O >1

Oral fluid swab H gene PCR
CT 26
C/O 35

MS2 Bacteriophage DNA
CT 24
C/O 35

Human Ribonuclease P gene
CT 23
C/O 35

What further information would you like?

A

MMR history - recent vaccine may give similar picture, and can cause a Measles-like illness

Exposure - any close contacts with a rash

Foreign travel

Immunosuppression

Pregnancy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

exam question - will be on exam

Case 1
IgG 5
C/O 13

IgM 3.9
C/O >1

Oral fluid swab H gene PCR
CT 26
C/O 35

MS2 Bacteriophage DNA
CT 24
C/O 35

Human Ribonuclease P gene
CT 23
C/O 35

What is the initial management of this patient?

A

Notify IPC -
Admit to negative pressure side room
FFP3 mask/ gown/ visor/ gloves

Notify public health for contact tracing

Notify occupational health for staff tracing

Vitamin A 2x doses for all children admitted with severe Measles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

exam question - will be on exam

Case 2 - 2 year old child
IgG >300
C/O 13

IgM 0.98
C/O >1

Oral fluid swab H gene PCR
CT 37
C/O 35

MS2 Bacteriophage DNA
CT 25
C/O 35

Human Ribonuclease P gene
CT 23
C/O 28

What are the possible clinical interpretations of these results?

What further testing would you order?

A

MS2 Bacteriophage detected - passed
Human Ribonuclease P detected - passed

controls accepted

IgM equivocal
IgG detected - strongly positive
RNA detected - very low level

  • recent immunisation
  • recent breakthrough infection - child has only had 1xMMR dose. So could develop an infection. Send PCR testing to Colindale for Measles typing
  • answer could be obtained through further history:
  • any recent immunisation
  • any recent travel/ epidemiological link to infection
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

When do children get their MMR vaccines?

A

1 year

3 years and 4 months

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

exam question - will be on exam

Case 3

Oral fluid swab H gene PCR
CT 40
C/O 35

MS2 Bacteriophage DNA
CT 25
C/O 35

Human Ribonuclease P gene
CT 40
C/O 28

What are the possible clinical interpretations of these results?

A

MS2 Bacteriophage detected - passed
Human Ribonuclease P not detected - failed

controls failed

Cannot reliably exclude a Measles infection, as the PCR was not successful due to inadequate sample quality.

Low level Measles RNA could be because of poor sample quality, but could also be due to an early infection

Suggest getting a repeat sample

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

exam question - will be on exam

Assessing Measles contacts

What are the important parts of the history?

A

Infectious period is 4 days before rash, to 4 days after rash

Exposure:
Household
Face-face (<2M)
Same room 15 mins
Large room for prolonged time e.g hospital bay

Patients:
MMR history - age born before 1970 assume immune
Immunosuppression
Pregnancy
Infants <12 months old

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

In what decade of birth should we assume that patients are immune to Measles?

A

If born before 19070 assume immune

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

exam question - will be on exam

Immunosuppressed Measles contact

What categories do we divide patients in to?

What are examples?

A

Group A
- those who are should develop and maintain adequate antibody response from past exposure or vaccination

Group B
- those who lose or may not maintain adequate antibody response
e.g BMt, leukaemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

exam question - will be on exam

Immunosuppressed Measles contact

Group A

What is the management?

All ages
Born before 1970
Born between 1970-1990
Born after 1990

A

Previous Measles IgG pos - assume immune
Previous Measles infection - assume immune

Born before 1970 (without Measles IgG result), and history of Measles infection - assume immune

Born before 1970 (without Measles IgG result), and no history of Measles infection - check IgG

Born between 1970 and 1990 (without Measles IgG result), and history of Measles infection - check IgG

Born between 1970 and 1990 (without Measles IgG result), and no history of Measles infection or vaccination - check IgG

Born after 1990 (without Measles IgG result), and history of 2xMeasles vaccines - check IgG

Born after 1990 (without Measles IgG result), and history of 1xMeasles vaccines - check IgG

Born after 1990 (without Measles IgG result), and history of no Measles vaccines - give IVIG

https://assets.publishing.service.gov.uk/media/653b880ae6c9680014aa9c1f/national-measles-guidelines-october-2023.pdf page 28

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

exam question - will be on exam

Immunosuppressed Measles contact

When does HNIG need to be given?

A

Give within 72 hours, up to 6 days

incubation period Measles is 7 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

exam question - will be on exam

Immunosuppressed Measles contact

You wish to do Measles IgG to see if they are immune.

However this result will not be back before day 6

What action would you take>

A

If cannot get test results and give IVIG within 6 days, then just give IVIG as soon as possible

17
Q

exam question - will be on exam

Immunosuppressed Measles contact

Group B

What is the management?

A

B(I)
- Measles IgG positive since treatment completed - assume immune
- No documented Measles IgG since treatment completed - Measles IgG test

B(II)
- IVIG regardless of status
This includes BMT/ Leukaemia

18
Q

exam question - will be on exam

Immunosuppressed Measles contact

Group B

You wish to test your contact for Measles IgG, but you will not have the test result within 6 days of exposure.

How will this affect your decision making?

A

Give IVIG regardless, if test result wont be back by 6 days after exposure

19
Q

exam question - will be on exam

Pregnant Measles contact

What is the management?

A
  • 2x MMR vaccines - assume immune
  • 1x MMR vaccine - Measles IgG
  • unvaccinated - Measles IgG

If Measles IgG not detected, then give HNIG

If cannot test and give HNIG within 6 days, then off HNIG

MMR cannot be given as teratogenic

20
Q

exam question - will be on exam

Infant <12 month Measles contact

Why are they at high risk of infection?

A

Not had MMR vaccine yet

Maternal transplacental antibodies are low, and reduce quickly after birth

21
Q

exam question - will be on exam

Infant Measles contact

How do you manage:
Infant <6 month old

A

assume susceptible and give HNIG regardless of maternal status

22
Q

exam question - will be on exam

Infant Measles contact

How do you manage:
Infant 6-8 month old

A

Household exposure -
assume susceptible and give HNIG regardless of maternal status

Outside household exposure -
administer MMR within 72 hours

23
Q

exam question - will be on exam

Infant Measles contact

How do you manage:
Infant >9 month old

A

give MMR vaccine within 72 hours

24
Q

exam question - will be on exam

Adult unvaccinated Measles contact

What PEP would you offer?

A

If non-immune, give MMR vaccine

Does not need HNIG if not immunosuppressed or pregnant

25
Q

exam question - will be on exam

What is SSPE?

Who is more at risk?

A

Rare, fatal, late complication of measles infection

Follows after infection in childhood, including after an unrecognised Measles infection.

Virus has been recovered from brains of patients who have died

1 case in every 25000 cases overall

Significantly higher risk if acquired earlier -
<2 year old rate is 1 in 8000

median interval is 7 years overall. Can range from 5 years to 30 years

26
Q

exam question - will be on exam

WHO plan to eradicate Measles

Why is this possible?

A

Initial plan was to eradicate in 2005 - this failed

Only humans infected - no animal/ environmental reservoir

accurate, accessible diagnostics

effective vaccine - 90% 1 dose, 2x doses >95% effective

Evidence of effective transmission interruption as Measles cases worldwide have dropped - showed it is possible

27
Q

exam question - will be on exam

IVIG dosing

What is the dose for immunosuppressed patients?

A

Immunosuppressed
0.15 g/kg

IVIG has high enough dose to be fully protective

28
Q

exam question - will be on exam

IVIG dosing

What is the dose for pregnant contacts

A

Pregnant IVIG is not practical, as need IV access

Give HNIG 3000mg

29
Q

exam question - will be on exam

IVIG dosing

What is the dose for infants

A

Infants IVIG is not practical, as need IV access

Give HNIG 0.6ml/kg up to maximum of 1000mg

30
Q

exam question - will be on exam

What is difference between HNIG and IVIG?

A

IVIG is given IV - this is first line PEP for highest risk patients

HNIG is alternative. It is given IM if cannot give IV, or because it is not practical to give IV such as at a GP practice. Often used for pregnant/ infant contacts

HNIG will likely attenuate disease, but probably not terminate an infection, so not used in immunosuppressed patients

31
Q

What PEP is required following inadvertent vaccination of Measles?

A

immunosuppressed - assess as usual. May need IVIG

Pregnancy - no PEP. But foetal follow up

32
Q

MMR given 8 weeks after receiving blood products

What actions should be taken?

A

When MMR is given within three months of receiving blood products, such as immunoglobulin, the response to the measles component may be reduced.

This is because such blood products may contain significant levels of measles-specific antibody, which could then prevent vaccine virus replication.

Where possible, MMR should be deferred until three months after receipt of such products.

If immediate measles protection is required in someone who has recently received a blood product, MMR vaccine should still be given.

To confer longer-term protection, MMR should be repeated after three months

33
Q

What are MMR contra-indications?

A

● pregnant women

● immunosuppressed

● anaphylactic reaction to a previous dose MMR vaccine

● anaphylactic reaction to neomycin or gelatine

Green book

34
Q

What rare side effects are associated with MMR vaccine?

A

Febrile seizures

Rash - due to Measles or Rubella replication

Immune thrombocytopenia - thought to be due to Rubella

Arthropathy

Virology 2 (57 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions