Past Papers Flashcards
Picture of influenza virus
What will it look like?
spherical - can have filamentous shape
lipid envelope
spikes - haemagglutinin and neuraminidase
segmented genome
80-120nm
check electron microscopy images - can look a bit like coronavirus with envelope and spikes
What are 4 recently circulating types of influenza?
Unclear answer
Influenza A (H1N1)pdm09
Influenza A (H3N2)
Influenza B/ Yamagata
Influenza B/ Victoria
Influenza A (H5N1) - Avian influenza may be circulating in wildlife. May be an appropriate answer
Influenza C detected less frequently, and usually does not cause public health issues as mild symptoms
Influenza D only infects cattle
Influenza treatment
What is first line drug mechanism of action?
Oseltamivir
unless known to be resistant e.g H1N1
neuraminidase inhibitor - prevents cleavage of siliac acid at cell surface, preventing virions from leaving surface
What vaccines are available for influenza?
Live intranasal
Inactivated IM
- adjuvant quadrivalent vaccine (aQIV)
- recombinant quadrivalent vaccine (QIVr)
- Cell-based quadrivalent vaccine (QIVc)
- egg-grown quadrivalent vaccine (QIVe)
vaccine response takes 2-4 weeks to fully develop
Who is eligible for influenza vaccine?
Live intranasal
- children aged 2-16
Inactivated IM
- >65 years old
- pregnant
- immunocompromised patients of any age, including children who can’t have live intranasal
- occupational - healthcare workers
Inactivated influenza vaccine types
When is each used?
- adjuvant quadrivalent vaccine (aQIV)
- recombinant quadrivalent vaccine (QIVr)
- Cell-based quadrivalent vaccine (QIVc)
- egg-grown quadrivalent vaccine (QIVe)
2-18 years old
- Live attenuated vaccine
- Cell-based quadrivalent vaccine (QIVc) - if LAIV contra-indicated
18-64 years old
- recombinant quadrivalent vaccine (QIVr)
- Cell-based quadrivalent vaccine (QIVc)
- egg-grown quadrivalent vaccine (QIVe)
> 65 years old
- adjuvant quadrivalent vaccine (aQIV)
- recombinant quadrivalent vaccine (QIVr)
- Cell-based quadrivalent vaccine (QIVc) - only when every attempt to use the above two has been exhausted
Which influenza strains are included in vaccines 2023?
Influenza A H1N1
Influenza A H3N2
Influenza B Victoria
Influenza B Yamagata
Which groups of people cannot have LAIV?
immunocompromised
LAIV contains porcine gelatine - refusal to have on personal grounds
Patient with egg allergy
Which vaccine should be given?
Inactivated
Live
Inactivated vaccines are egg free/ low albumin content - safe to give
- recombinant quadrivalent vaccine (QIVr)
- Cell-based quadrivalent vaccine (QIVc)
- adjuvant quadrivalent vaccine (aQIV)
- egg-grown quadrivalent vaccine (QIVe) - do not give
LAIV
- safe for use in children with allergy mild/mod
- if anaphylaxis - only give if in hospital. Intranasal administration is less likely to have a systemic reaction than systemic
What are the ingredients for PCR?
template DNA
nucleotides - deoxyribsonucleotide triphosphates
primers - these are short stretches of single-stranded DNA that are complementary to the 3’ ends of sense and antisense strands.
Polymerase enzyme e.g reverse transcriptase or Taq polymerase
Magnesium ions - helps with DNA polymerase
Buffer - provides suitable chemical environment for DNA polymerase activity
What are steps of DNA PCR?
Denaturation - heating 94degC causes hydrogen bond breakdown and DNA strand separation
Annealing - cooled to 50-60degC, primer binding to target DNA
Extension - DNA polymerase extends the 3′ end of each primer along the template strands using nucleotides
Amplification - repeated cycles heating from 50-94degC
Fluorescent probes e.g Sybr Green can bind to DNA, and fluorescent show real-time PCR. Does not fluoresce if not bound
MSM with jaundice and history of unsafe sexual practices
HBsAg pos
HBeAg pos
Anti-HBe neg
How would you report?
Evidence of current “e” antigen positive HBV infection
unclear if acute or chronic
MSM with jaundice and history of unsafe sexual practices
HBsAg pos
HBeAg pos
Anti-HBe neg
Who you you report to (agencies)?
HPU - if acute HBV infection
iCaSH/ GP - inform if patient consents
sexual partners
MSM with jaundice and history of unsafe sexual practices
HBsAg pos
HBeAg pos
Anti-HBe neg
What other tests would you ask for?
anti-HBc IgG
anti-HBc IgM - check if acute or not
HBV DNA
LFTs/ Coagulation
UEs - if needs tenofovir
Liver USS/ Fibroscan
Liver biopsy
HDV serology
HCV
HIV
HAV IgG - immunity screen
STI - syphilis, chlamydia, gonorrhoea
Returning traveller from Guinea ?VHF
you receive sample for EBV serology
What do you do with the sample?
Store - do not handle until VHF status known
If needs handled, use Cat 3
Contact requesting team
Returning traveller from Guinea
How many days after return would you worry about possibility of VHF?
21 days
Returning traveller from Guinea
What symptoms would prompt you to refer sample to Cat4 facility (RIPL)
Fever >37.5degC
extensive bleeding/ bruising
needs exposure history - e.g country or activities e.g caves
Returning traveller from Guinea suspected VHF
name 3 other viruses which need to be handled in Cat 4 conditions
Herpes B virus
Henipah virus - Hendra/ Nipah
Smallpox (Variola)
VHF -
Ebola
Marburg
Lassa
Lujo
CCHF
Returning traveller from Guinea suspected VHF
What is most important infection to exclude?
malaria
NSI
HBsAg pos source
What action would you take for recipient
- No previous vaccine
- known vaccine responder
- known vaccine non-responder
- No previous vaccine - give accelerated vaccine and HBIG
- known vaccine responder - give booster if >1 year since last dose
- known vaccine non-responder - give vaccine and HBIG now and in one month
important - remember second dose of HBIG
accelerated vaccine - zero, one, two and 12 months
NSI
HBsAg unknown source
What action would you take for recipient
- No previous vaccine
- known vaccine responder
- known vaccine non-responder
- no previous vaccine - give accelerated vaccine (no HBIG)
- known vaccine responder - give booster if >1 year since last dose
- known vaccine non-responder - give vaccine and HBIG now and in one month
Picture of 9 month old vocal cord with lesion
What is the lesion?
Respiratory papillomatosis caused by HPV
benign lesions
9 month old with pharyngeal respiratory papillomatosis
How did this occur?
Probably transferred from genital warts (HPV6/11) during delivery
mother probably not vaccinated
9 month old with pharyngeal respiratory papillomatosis
What is treatment?
surgical removal
intra-lesion cidofovir has some effect
recurrence is very common even despite surgical procedures
9 month old with pharyngeal respiratory papillomatosis
how to diagnose?
Histology
9 month old with pharyngeal respiratory papillomatosis
Which HPV types contribute to this?
HPV 6/11 cause genital warts and respiratory papillomatosis
HPV 16/18 cause cancer
What other diseases does HPV causes?
Cervical cancer - HPV 16/18
Penile cancer - HPV 16/18
Oropharyngeal cancer - HPV 16/18
Genital/ Anal warts - HPV 6/11
Respiratory papillomatosis - HPV 6/11
Who is eligible for HPV vaccine given?
- girls/ boys aged 12/13
2 doses
second dose 6-12 months after first
- also MSM have not benefited from previous girls vaccination campaign. So since 2018 MSM up to 45 have been eligible for vaccination
What does the HPV vaccine cover?
Gardasil 9
Gardasil 9 protects against 9 types of HPV:
6, 11, 16, 18, 31, 33, 45, 52 and 58.
Between them, types 16 and 18 are the cause of most cervical cancers in the UK (more than 80%).
Types 31, 33, 45, 52 and 58 cause an additional 15% of cervical cancers.
Types 6 and 11 cause 90% of genital warts
HPV vaccine
What antigens does it target?
sub-unit vaccine - contains virus-like particles containing L1 major capsid protein
Closely resemble the virus, but lack viral DNA
Gardasil 9 targets - HPV types 6, 11, 16, 18, 31, 33, 45, 52, and 58
98-100% effective
