Past Papers 4 Flashcards
What are clinical features of HHV8 infection?
Immunocompetent -
asymptomatic
flu-like illness with maculopapular rash
acute hepatitis
Multicentric Castleman Disease
Immunocompromised -
Kaposi sarcoma
Primary effusion lymphoma
How is HHV8 transmitted?
unclear
saliva likely most common transmission method
also detected in genital secretions
potentially through blood transfusions
Patient with HHV8 infection
What infection control measures need to be inplacE?
Recommendations do not exist
What is vaccine effectiveness?
Measure of how much it protects against:
severe disease/ hospital admission/mortality
reducing rate of infection in population
reducing transmission and spread of virus
duration of protection
Can measure in trials by comparing those vaccinated/ not vaccinated
or in real world data following vaccine administration
Vaccine effectiveness
What is definition of herd immunity?
When a significant portion of a population are immune to an infection. Either by immunisation or prior infection
Once this level of herd immunity is reached, it restricts viral spread through a population, and thereby reduces the risk of a non-immune person developing infection
Vaccinating populations
What is the “free riding” problem?
Herd immunity should protect those who are vulnerable
however some people decide not to get vaccinated due to various beliefs:
belief vaccines are ineffective
mistrust of healthcare
peer pressure
bandwaggoning
religious beliefs
What are the components of the innate immune system?
Physical barrier - skin, mucusa
Chemical barrier - saliva, tears, stomach acid
Cells -
phagocytic cells - macrophages/ neutrophils
NK cells
lymphoid cells
Complement
Long essay
Compare and contrast the strategies of prophylactic and pre-emptive therapy for CMV infection in solid organ transplant
recipients
CMV-seronegative recipients who receive a solid organ transplant from a donor who is seropositive, should be offered prophylaxis against primary infection, using oral valganciclovir, oral valaciclovir or intravenous ganciclovir.
The same should apply where either the donor or recipient is seropositive if the patient is treated with T-cell depleting therapies.
Continue prophylaxis for 3-6 months
If donor and recipient are both seropositive, and patient is not treated with T-cell therapy:
For renal/ liver/ cardiac transplant recipients: no prophylaxis is recommended.
For lung transplant recipients: the recommended prophylactic strategy is oral valganciclovir or oral valaciclovir.
Short answer questions
A 37 year old woman presents to the Accident and Emergency Department with severe respiratory symptoms. She returned two days previously from Viet Nam.
What advice would you give about her management
DDx - Avian influenza, COVID, Melioidosis
Patient History - travel, layovers, unwell contacts, activities e.g caves, animals. Check PROMED
IPC - side room with respiratory precautions. FFP3 if avian influenza suspected or aerosol generating procedures. Until diagnosis is understood
Short answer questions
Write short notes on the epidemiology, symptoms, diagnosis and treatment of chikungunya virus
Epidemiology - Africa, Asia, Carribbean, South America. Rare cases in south of France
incubation 4-8 days
Symptoms -
fever
polyarticular arthritis - ankles/ wrists most common
maculopapular rash
Aged >65 - more likely to have severe disease, and potentially death
diagnosis - serology/ PCR
management - analgesia
prevention - mosquito avoidance
complications - chronic arthralgia. If severe, can have meningoencephalitis, cardiac failure
Short answer questions
Write short notes on the epidemiology, symptoms, diagnosis and treatment of chikungunya virus
- What are important differentials to consider?
Fever/ arthralgia/ rash
Chikungunya
Dengue
Zika
O’Nyong’Nyong
Malaria
Leptospirosis
Rheumatic fever
Short answer questions
Write short notes on the epidemiology, symptoms, diagnosis and treatment of chikungunya virus
- Which species of mosquito transmit this?
Aedes aegypti
Aedes albopictus
Short answer questions
Discuss the laboratory investigation of immunity to measles, mumps and rubella virus
History taking - if history of infection, or appropriate immunisation, then no investigation necessary
Usually scree occupational health, especially from tropics
IgG testing for immunity - Measles/ Rubella - if immune, can assume Mumps immunity
If negative results - susceptible
Equivocal results without history of infection or immunisation, would consider non-immune
short answer questions
Discuss the management of a 12 week pregnant woman in contact with her young son who developed a maculopapular rash two days ago
History of previous MMR immunisation
does pregnant patient have rash/ fever
any contacts with rash - may have a shared exposure
DDx - parvo virus, measles/ rubella
Parvo - test bloods for IgG/ IgM. If neg, follow up bloods in 4 weeks
Measles/ Rubella - if vaccinated, do not test. If negative, then follow up bloods in 4 weeks to assess if acquired infection
ask
short answer questions
Discuss the management of a 12 week pregnant woman in contact with her young son who developed a maculopapular rash two days ago
DDX - Parvo, Rubella, Measles
How long is her son infectious for?
Infectious periods
Parvo - 10 days before rash, to day of onset
Rubella - 7 days before rash, to 10 days after onset
Measles - 4 days before rash, to 4 days after onset
short answer questions
A 57 year old man is admitted to hospital with severe headache, fever, confusion, becoming unconscious. Discuss the virological diagnosis and treatment you would recommend
History taking - timing of symptoms, travel history, animal exposure, sexual, unwell contacts
CTB
Bloods - including HIV test
Blood culture
Respiratory swab e.g covid/ influenza
Rash - swab e.g VZV
Stool PCR - enterovirus
CSF - HSV/ VZV/ Adeno/ Entero
Travel - JEV, WNV, Dengue, Nipah, Malaria
Immunosuppressed - JC, CMV, HHV6/7, HIV
STI- Syphilis
Animals- rats LCMV, Leptospirosis
Animal bites - rabies
Tick bites - TBEV, Lyme
Macaque - Herpes B virus
short answer questions
A 24 week pregnant woman presents to her GP with a two day history of severe chickenpox.
What would you suggest for the management of this patient?
Confirm diagnosis - swab
VZV IgG - check not disseminated reactivation
LP if encepahlitis suspected
Bloods to look for hepatitis
CXR to look for pneumonitis
Admit - IV aciclovir, 10mg/kg IV TDS. Once improving/ no new lesions, then switch to oral
Treat any secondary bacterial infections
IPC - side room, respiratory precautions until lesions crusted
Public health - check for other contacts
Neonate - risk of FVS
short answer questions
A 24 week pregnant woman presents to her GP with a two day history of severe chickenpox.
What is the risk of foetal varicella syndrome?
<13 weeks 0.4%
13-20 weeks 2%
> 20 weeks minimal risk
short answer questions
What are the signs of foetal varicella syndrome?
LBW
eye lesions
skin scarring
limb hypoplasia
neurologic involvement
short answer questions
A 39 year old man who had a living unrelated bone marrow transplant 4 weeks ago is admitted to hospital with severe respiratory symptoms. Adenovirus DNA is detected by PCR in a BAL.
What advice would you give on the management of the patient?
Assess which organs are involved
- LP for meningitis if indicated
- bloods look for hepatitis
viral load - confirm systemic involvement, and for monitoring treatment
Cidofovir treatment
Needs fluids + probenicid
Look for other diagnoses - e.g covid/ influenza/ PCP/ bacterial/ fungal
short answer questions
A term baby is born with cerebral calcifications and chorioretinitis. His CMV IgM and Toxoplasma gondii IgM results on a clotted blood taken two days after birth are negative.
Does this exclude infection with these two organisms and what management would you recommend?
Does not exclude CMV or Toxoplasma
Check mothers samples for evidence of CMV or Toxoplasma in pregnancy
Check urine/ Saliva for CMV within first 3 weeks
Send baby blood for Toxoplasma IgM/IgG/ Dye test
short answer questions
A 44 year old CMV antibody negative man is given a lung transplant from a CMV antibody positive donor.
Discuss the ideal management of this case, and the likely outcome with and without interventive management
Likely to develop a primary CMV infection - could have severe hepatitis/ pneumonitis/ colitis
cannot reduce immunosupression. So give pre-emptive ganciclovir for 100 days following transplant
