Measles Flashcards

Question

Can the following sample be tested for Measles PCR: 1)Urine? 2)Dry swab

Answer 1

1)Highly variable Not advised in the UK 2)Yes for PCR

Answer 2

Total IgG < 1mg/L The test needs to be repeated

Answer 3

The relative level of Measles IgG in OF sample may indicate High avidity Measles IgG in SERUM sample confirms breakthrough infection

Answer 4

They are entered on the WHO global Measles Nucleotide Sequence (MeaNS) database ## Footnote This helps in monitoring global Measles elimination efforts.

Answer 5

Suspected case + lab evidence of ACUTE Measles: -IgM in serum/OF with no recent vaccination OR -Confirmed WT-Measles RNA in any clinical sample

Answer 6

Lab confirmed with NO evidence of 2 doses of Measles containing vaccine

Answer 7

Detection of Measles virus RNA in a suspected case + Mild/atypical symptoms + reliable history of 2 doses of vaccine *Measles IgM in serum may be negative. Confirmation can be established by high avidity IgG in serum OR high levels of MS-IgG in OF,

Answer 8

Qualitative (pos/neg/equ) OR Quantitative (defined measure) Usually EIA is used Highly specific BUT less sensitive

Answer 9

Oral fluid (OF) sample sent to VRD REGARDLESS of any local test results,

Answer 10

As soon as possible and up to 6 weeks after the onset of rash

Answer 11

All samples should be forwarded to VRD for Confirmation and Genotyping

Answer 12

Assessment of the epidemiological features

Answer 13

Start based on Clinical + epidemiological features (EPI) without waiting for lab results

Answer 14

Use appropriate lab samples for testing at the right time to reduce the risk of false negative results

Answer 15

To decide on PH management and actions

Answer 16

Lab confirmed, EPI confirmed, Likely/probable, Likely breakthrough, Unlikely/possible *Classification may change *Likely and unlikely are qualitative judgment

Answer 17

Clinically classical case + Direct EPI link to: A confirmed case (onset of symptoms occurred within 7-21D of exposure) OR Related to another EPI confirmed case (eg in an OB) This term is used for SURVEILLANCE purposes to define confirmed cases in the absence of a lab test to confirm measles.

Answer 18

Clinically classical case + EPI features* *Either increase the likelihood of the patient having been exposed AND/OR *Favour the diagnosis of measles relative to other causes of rash illness.

Answer 19

Suspected case in a patient who had: 2 doses of Measles containing vaccine (usually at least 6Y after vaccination) OR Previous confirmed Measles infection (IgG positive) **The case will usually have mild symptoms AND epidemiological information that suggest exposure to Measles (RARE)

Answer 20

Suspected case does NOT meet definition of Likely case *NOT CCC OR *No EPI=No recent conformed case and has not visited an area with OB during InP

Answer 21

Factors increasing the risk of exposure Factors favoring the diagnosis of 1ry Measles infection

Answer 22

* Members of community known to be more susceptible * Visited an area where Measles is circulating during the incubation period * Attendance to large gatherings

Answer 23

* Age: higher among adolescents/young adults * Lack of immunity/incomplete vaccination + No prior infection

Answer 24

ALL Contacts of EPI/Lab confirmed cases AND IS Contacts of Likely cases (including BT)

Answer 25

Contacts of unlikely cases should await the results of OFT ## Footnote Unlikely cases are defined as having NO EPI OR not being CCC.

Answer 26

If the index is Unlikely Measles with IS contact within 6D of exposure. If the index is Likely Measles with IC contact within 6D of exposure. **IS contact of likely and ALL contacts of confirmed cases are assessed and managed without waiting for results.

Answer 27

To avoid significant public health actions if diagnosis is excluded (eg administering MMR/HNIG to exposed infants in nursery settings). To inform use of HNIG/IVIG for vulnerable contacts, during periods of low level transmission.

Answer 28

To inform the risk assessment of an IS contacts.

Answer 29

With HPT Date of onset of symptoms, Date of onset of rash, and History/dates of MMR vaccine

Answer 30

False Exclusion depends on Timing and adequacy of the sample and Tests undertaken.

Answer 31

CF, EPI features, Vaccination history, and Lab results

Answer 32

Should stay at home (No work/school/nursery) and Avoid contact with vulnerable ppl for the entire InP (4d b4 rash 4d after) GIVEN HIGH INFECTIVITY > return ONLY after full recovery.

Answer 33

IS may be infectious for longer and may not display typical symptoms

Answer 34

Measles ## Footnote It's important to consider testing timing and adequacy.

Answer 35

High vaccination coverage with 2 doses of MMR vaccine (=/>95%)

Answer 36

Information on symptoms and instructions to exclude themselves if symptoms develop

Answer 37

False ## Footnote PEP is of limited effectiveness.

Answer 38

* Immunosuppressed contacts * Pregnant women and infants <12 months * Healthcare workers * Healthy contacts

Answer 39

Can be source of transmission —> need urgent assessment +/-Exclusion from work Vaccination of un-immunised contacts should confer benefit against FUTURE exposures and will protect against Rubella & Mumps.

Answer 40

Unlikely to benefit unless offered rapidly following exposure

Answer 41

Mass vaccination of susceptible people To prevent tertiary transmission

Answer 42

* Exposure risk (is index case 1ry or BT) * Vaccination status/susceptibility to Measles **For IS contacts asses the level of IS

Answer 43

Contact tracing should identify close contacts within the InP CC including HH  F2F contact of any length >15 minutes in a small, confined area (eg room in a house, classroom, 4-bed hospital bay (including HCW)

Answer 44

Consider even limited exposure; as are more likely to develop severe Measles disease —> Hence ANY LEVEL OF CONTACT shud trigger assessment Even if the index case has BT infection Without waiting for lab results ***IC contacts of BT infection does not need Risk assesmnet/PEP

Answer 45

PPL exposed in a shared setting (ED/GP waiting area) where level of contact in unclear. *If there are known IS involved —> manage as CC (rapid assess + PEP) *If there is a List (not known IS status) —> WARN and INFORM LETTER/MSGS *If there is no list —> writing to local HC providers/info leaflets/posters

Answer 46

IVIG (Intravenous Immunoglobulin) At risk of severe Measles

Answer 47

* Level of immunosuppression * Likelihood of retaining pre-existing Measles immunity

Answer 48

ONLY if fully vaccinated OR Born before 1957

Answer 49

Do not require additional IVIG if the most recent dose was administered =/<3 weeks before exposure. *Their IVIG requirement will be advised by their immunologist.

Answer 50

Group A and B Based on their ability to maintain adequate Ab from past exposure/vaccination.

Answer 51

Group A: able to develop and maintain adequate Ab from any prior vaccination/infection. Can be managed based on evidence of protection at any time (b4/since diagnosis/ttt end) Recommended to check their Measles status b4 exposure —> if not available check ----------------------- Group B: Unlikely to hv developed/maintained adequate Ab levels from past B(I): Managed based on Measles IgG test at time of exposure/at any point since the end of TTT/Diagnosis. B(ii): Require IVIG post exposure WITHOUT testing

Answer 52

Assessment of susceptibility based on: Age /History of Measles infection/Vaccine status --> Group A only Measles IgG result since diagnosis/ttt (Group B /1)

Answer 53

If born b/w 1970-1990 with NO history of infection/Vaccination. If born after 1990 and had ONE dose of MMR vaccine If born after 1990 and UNvaccinated

Answer 54

Specificity is high; sensitivity remains low. Hence recommendations about PEP for equivocal results will differ by age and type of vulnerability.

Answer 55

For IS patients where exposure is recognised late OR   Found to be Ab negative/equivocal b/w 6-18D after exposure >> d/w the specialist caring for the individual should take place, and IVIG may be considered in order to attenuate infection.

Answer 56

No further IVIG dose required Consider a further dose of IVIG.

Answer 57

<1% are Ab negative.

Answer 58

<10% are Ab negative.

Answer 59

Detectable measles Ab by Neutralisation assays.

Answer 60

Routine Ab test lack sensitivity > A high proportion of those found to be Equivocal/Negative are likely to be truly immune.

Answer 61

~90% respond.

Answer 62

~95% will be protected.

Answer 63

HNIG Attenuation of disaese.

Answer 64

UNLIKELY ## Footnote Most UK mothers are born after Measles vaccination was introduced (1968).

Answer 65

Low and wanes rapidly (Few Weeks) ## Footnote This contrasts with mothers who had previous infections, where antibodies wane after a few months.

Answer 66

*HNIG regardless of mum status (Maternal Ab can interfere with the MMR response). *HH C HNIG/ non-HH C MMR *MMR ##Ideally HNIG within 72H but up-to 6D MMR only 72H

Answer 67

Within 3 days

Answer 68

NO Doses offered <1Y should be discounted and children should be offered 2 doses of MMR vaccine according to the national schedule The efficacy of a dose of vaccine b/w 6-11M < that at 12-13M, due to interference from maternal Ab. ***All additional immunisations should be recorded in the red book and should be notified to the local Child Health Information System (CHIS).

Answer 69

PEP with HNIG or IVIG D/W UKHSA duty dr case by case

Answer 70

Pre-term delivery, HIGH RISK for premature/low birth weight infants

Answer 71

69% Efficacy increases with dose.

Answer 72

The use of MMR vaccine Limited evidence suggests it may prevent disease/reduce severity if given within 72H --> beyond future protection IN OB settings, when given to those who has not significantly exposed yet can prevent tertiary transmission.

Answer 73

Either WT Measles and Vaccine rash OFT can be used to type the virus (vaccine vs WT) if taken within 1W of onset.

Answer 74

4D b4 rash onset

Answer 75

From the onset of rash in the index case. From the last day of exposure to the index case

Answer 76

IS: risk assess as a potential exposure to measles Pregnant women: No PEP, Report to Inadvertent vaccination during pregnancy.

Answer 77

0.15 g/kg ~11 IU/Kg Measles Ab

Answer 78

For pregnant: ~3g For infants: 0.6 ml/kg up to a maximum of 1g

Answer 79

Be excluded from work from the 5th day after the first exposure to 21 days after the final exposure If tested rapidly and are IgG positive within 7Dof exposure, can continue to work BUT report to OH if developed symptoms b/w 7D after 1st exposure and 21D after last exposure. They can return if they remain symptom-free for at least 14 days after receiving the MMR vaccine.

Answer 80

Exclude until 4 full days after onset of the rash ## Footnote They should be treated as epidemiologically confirmed cases --> send lab test and notify HPT

Answer 81

At risk of developing prolonged/severe Measles & complications.  Pneumonitis is the most common cause of death.  Most at highest risk: Severely CMI (recent BMT, 1ry T-cell dysfunction, AIDS, ALL)

Answer 82

1)Post-infectious encephalomyelitis   1W after onset of rash AI-demyelination (virus rarely found in the brain) 2)Measles inclusion body encephalitis (Acute encephalitis of the delayed type): IS ONLY Might occur without measles-like illness (exposure history possible W/M) Acute neurological compromise/decreased consciousness/Seizure/progressive N Measles RNA can normally be detected from clinical specimens for several D/W 3)SSPE VERY RARE (0.01%), kids infected <1Y: 1/8000 (16X > infected >5Y). FATAL. LATE complication (median 7Y -up to 2-3 decades later)  May follow unrecognized Measles infection (WT virus found in brain) Progressive neuro-cognitive symptoms —> Coma —> Death.

Answer 83

Once dose of MMR is at least 95% effective in preventing clinical Measles  92% effective in preventing 2ry cases among HH contacts.

Answer 84

Primary failure: when an individual fails to make an initial immunological response to the vaccine. RARE. particular after a SINGLE dose. Secondary failure: when an individual responds initially BUT then protection wanes over time.