Past Papers 10 Flashcards
An obstetric registrar calls regarding a 32-year-old pregnant woman attending for a 36-week scan.
She reports onset of a painful genital ulcer 3 days ago. She has no previous history of genital ulceration. Her male partner also reports first episode of new multiple genital ulcers.
Write 5 points of advice that you will give
Swab lesions to confirm diagnosis
HSV type-specific IgG - confirm whether primary or secondary
Aciclovir oral treatment - 400mg TDS. Third trimester - continue suppressive treatment until delivery. If first/ second trimester, then aciclovir from week 36
Caesarean section recommended for primary genital herpes developing in third trimester
Consider alternative diagnoses for ulcers - e.g syphilis
Avoid sexual intercourse with partner
Consider repeat STI screen - if suspect that partner has been having sex with multiple partners. Chlamydia/ Gonorrohoea/ Syphilis/ HIV/ HBV/ HCV
Primary genital herpes in pregnancy
What is the treatment:
First/ second trimester
Third trimester
First/ second trimester -
aciclovir treatment
suppressive therapy from 36 weeks
normal delivery if delivery not within 6 weeks of lesions appearing
Third trimester -
aciclovir treatment
continue suppressive therapy until delivery
caesarean section
Primary genital herpes in pregnancy
What is HSV aciclovir treatment dose?
What is HSV aciclovir suppressive dose?
treatment dose -
400mg TDS usually 5, longer if lesions have not fully healed
suppressive dose -
400mg BD
A community midwife calls having been telephoned by a 25-week pregnant woman of Indian origin, whose 3-year-old son just developed a vesicular rash with fever, which the GP has diagnosed as likely chickenpox. The mother thinks she may have had chickenpox twice in her childhood in India.
What immediate steps would you undertake?
Swab child for VZV to confirm. May be HSV/ Enterovirus
Booking bloods VZV IgG - India has low prevalence of VZV. Also having it twice seems strange
Advise to avoid further exposure to the rash until immune status known
Worsening advice - if develop rash/ fever/ SOB/ confusion to seek medical advice
Clarify MMR history as from India
A GP calls for advice regarding a 14-week pregnant primary school teacher presenting with acute symmetrical arthritis affecting both hands and wrists. She reports having had a 2-day history of fine rash but this is no longer visible. There have been reports of several children absent from school due to rash illness.
What two viral infections would you be most concerned about, and how would you investigate for them?
Parvo B19
- Parvo B19 IgM/ IgG
- if negative, repeat 4 weeks after rash onset
Rubella
- MMR vaccine history
- IgG testing. If negative, repeat 4 weeks after symptom onset
- oral fluid testing of other children
- epidemiological information regarding outbreaks
A biomedical scientist asks you to call the obstetrician with results of CMV serology for a pregnant woman whose fetus has been found to have polyhydramnios on a 20-week ultrasound scan.
A current blood sample
CMV IgM positive
CMV IgG positive
12 week booking bloods
CMV IgM positive
CMV IgG positive
CMV IgG avidity low
What is your result interpretation, risk assessment for pregnancy outcome and immediate plan
Perform CMV IgG avidity on current sample. Rising avidity would confirm there has been a recent CMV infection. This may be primary or secondary
If recent infection confirmed, discuss with parents the diagnosis. No need for amniocentesis. If diagnosis remains uncertain, offer CMV amniocentesis for CMV PCR
Transmission. A pregnant woman can pass CMV to her fetus following primary infection, reinfection with a different CMV strain, or reactivation of a previous infection during pregnancy. Risk of transmission for primary infection is 30 to 40% in the first and second trimesters, and 40 to 70% in the third trimester
At birth - urine/ saliva for CMV PCR. Ophthalmology/ Audiology/ MRI brain. Consider treatment if other severe features
A biomedical scientist asks you to call the obstetrician with results of CMV serology for a pregnant woman whose fetus has been found to have polyhydramnios on a 20-week ultrasound scan.
A current blood sample
CMV IgM positive
CMV IgG positive
12 week booking bloods
CMV IgM positive
CMV IgG positive
CMV IgG avidity low
Aminocentesis - CMV DNA - negative
Interpret this profile and what further advice would you give assuming the pregnancy will continue to term and live birth.
Include CMV-specific investigation[s] at birth
Aminocentesis normally performed after 21 weeks when foetal kidneys are developed
CMV testing on amniocentesis is about 95% sensitive, so may be a false- negative. Need to test again at birth
At birth - urine/ saliva for CMV DNA PCR. Ophthalmology/ Audiology/ MRI brain. FBC/ UE/ LFT to assess for other organs affected. Full examination of skin/ lungs
Consider treatment if tests positive and other severe features
If negative at birth, serology could reflect either:
- low level reactivation
- recent infection/ re-infection, without infection of foetus
Transmission. A pregnant woman can pass CMV to her fetus following primary infection, reinfection with a different CMV strain, or reactivation of a previous infection during pregnancy. Risk of transmission for primary infection is 30 to 40% in the first and second trimesters, and 40 to 70% in the third trimester
A GP calls for advice regarding a 14-week pregnant primary school teacher presenting with acute symmetrical arthritis affecting both hands and wrists. She reports having had a 2-day history of fine rash but this is no longer visible. There have been reports of several children absent from school due to rash illness.
Investigations on a current serum:
Parvovirus IgG Positive
Parvovirus IgM Positive
Rubella virus IgG Positive
Rubella virus IgM Negative
Investigations on an antenatal booking serum at 12 weeks’ gestation:
Parvovirus IgG Negative
Parvovirus IgM Negative
Rubella virus IgG Positive
Rubella virus IgM Negative
What is your result interpretation, and what advice would you give regarding risk to the fetus?
Rubella - likely reflect previous MMR vaccination
Parvo B19 seroconversion - likely recent acute infection
Doppler USS foetus - look for features such as hydrops foetalis
If features present, amniocentesis for Parvo B19 DNA PCR
If positive, consider foetal transfusion
Risk of foetal infection by gestation
Under 4 weeks: 0%
5 to 16 weeks: 15%
Over 16 weeks: 25 to 70%, increasing with gestation
Risk of foetal adverse outcome:
Under 20 weeks:
9%
Over 20 weeks:
1%
Parvo B19 infection in pregnancy
What is risk of foetal infection by age?
<4 weeks
5-16 weeks
>16 weeks
What is risk of adverse foetal outcome?
<20 weeks
>20 weeks
Risk of foetal infection by gestation
Under 4 weeks: 0%
5 to 16 weeks: 15%
Over 16 weeks: 25 to 70%, increasing with gestation
Risk of foetal adverse outcome:
Under 20 weeks:
9%
Over 20 weeks:
1%
VZV infection in pregnancy
What is the risk of intrauterine infection by age?
<28 weeks
28-36 weeks
>36 weeks
What is the risk of foetal varicella syndrome?
<13 weeks
13-20 weeks
>20 weeks
intrauterine infection by age:
Under 28 weeks: 5 to 10%
28 to 36 weeks: 25%
Over 36 weeks: 50%
Foetal varicella syndrome
Under 13 weeks: 0.4%
13 to 20 weeks: 2%
>20 weeks - unlikely to develop
A community midwife calls having been telephoned by a 25-week pregnant woman of Indian origin, whose 3-year-old son just developed a vesicular rash with fever, which the GP has diagnosed as likely chickenpox. The mother thinks she may have had chickenpox twice in her childhood in India.
VZV IgG 6IU/ml
What is your result interpretation, risk assessment of the contact and
recommendations regarding prophylaxis?
Non-immune to VZV - susceptible
Definite exposure - household contact. Try and limit further contact
Start aciclovir 7 days after first exposure date - 24 hours before rash onset
Worsening advice - if develops rash/ fever/ SOB/ confusion then to seek medical advice
If does not develop infection, consider VZV immunisation following delivery
VZV exposure in pregnancy - 70% risk of acquiring infection in susceptible women
A number of HIV serology results are on the authorization queue for your action. Please review these results and report them with appropriate comments. Indicate if this is a final report or interim (include verbal report to requester if you are not ready to issue
any report yet). Also indicate if you are waiting for further tests on the sample and the nature of these further tests
https://www.rcpath.org/static/80d54920-b6e2-45aa-bdb6c34026e99179/Part-2-Virology-sample-questions.pdf
Sample A
Report status - final or interim
HIV1/2 antibody + p24 antigen
Further comments
Sample A
Final report
2x positive antibody/antigen tests plus 2rd immunoblot is positive - so can release final report
Immunoblot - HIV1 positive
Further comments:
Please send a repeat sample for confirmation
Please send an EDTA sample for HIV viral load
Sample will be sent for avidity testing
Recommend testing for HBV/ HCV
Refer patient to GUM
A number of HIV serology results are on the authorization queue for your action. Please review these results and report them with appropriate comments. Indicate if this is a final report or interim (include verbal report to requester if you are not ready to issue
any report yet). Also indicate if you are waiting for further tests on the sample and the nature of these further tests
https://www.rcpath.org/static/80d54920-b6e2-45aa-bdb6c34026e99179/Part-2-Virology-sample-questions.pdf
Sample B
Report status - final or interim
HIV1/2 antibody + p24 antigen
Further comments
Final report
Intermediate reactivity in screening assay, not confirmed by 2nd assay
only 1 test positive - need 3 tests positive to confirm a result, or positive antibody + positive RNA PCR
HIV Antibody/ antigen status - indeterminate
Further comments:
Send repeat sample for testing
Send sample for HIV1 RNA PCR - if positive HIV infection is confirmed. If negative, antibody results are confirmed as false-posiitve
May reflect very early infection, particularly if immunoassay 2 is less sensitive, and immunoassay 1 is lowish positive
Clarify if any history of recent exposure
https://www.cdc.gov/hiv/pdf/guidelines_testing_recommendedlabtestingalgorithm.pdf
A number of HIV serology results are on the authorization queue for your action. Please review these results and report them with appropriate comments. Indicate if this is a final report or interim (include verbal report to requester if you are not ready to issue
any report yet). Also indicate if you are waiting for further tests on the sample and the nature of these further tests
https://www.rcpath.org/static/80d54920-b6e2-45aa-bdb6c34026e99179/Part-2-Virology-sample-questions.pdf
Sample C
Report status - final or interim
HIV1/2 antibody + p24 antigen
Further comments
Final report
HIV 1 & 2 both detected
Further comments
Please send a repeat sample for confirmation
HIV1 and HIV2 RNA testing by PCR to follow
HIV1 avidity
HIV1/2 proviral DNA testing
Recommend testing for HBV/ HCV
Refer patient to GUM
A number of HIV serology results are on the authorization queue for your action. Please review these results and report them with appropriate comments. Indicate if this is a final report or interim (include verbal report to requester if you are not ready to issue
any report yet). Also indicate if you are waiting for further tests on the sample and the nature of these further tests
https://www.rcpath.org/static/80d54920-b6e2-45aa-bdb6c34026e99179/Part-2-Virology-sample-questions.pdf
Sample D
Report status - final or interim
HIV1/2 antibody + p24 antigen
Further comments
Final report
HIV 1 detected (p24 antigen present in HIV1 only)
Further comments
May be a primary HIV1 infection
Ask clinical team about recent exposure/ seroconversion symptoms
Please send a repeat sample for confirmation
HIV1 RNA PCR
HIV1 p24 antigen neutralisation
HIV1 avidity
Recommend testing for HBV/ HCV
Refer patient to GUM
