Past papers 2 Flashcards
Components of cell walls
- NAG
- Lipid A
- Ergosterols
- Mycolic acid
- LPS
- Mycobacteria
- Fungi
- Peptidoglycan
- LPS
Lipid A - endotoxin - Mycobacteria
Mycolic acid - Fungi
Ergosterol - Peptidoglycan
The sugar component consists of alternating residues of β-(1,4) linked N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM)
Identification of organisms
- Modified Zn stain
- Thin blood film – Giemsa stain
- Concentrated iodine
- Calcofluor white stain
- Filamentous fungi on BAL
- Cryptosporidium
- Ova in stool
- Malaria
- Filamentous fungi on BAL
Calcofluor white stain - used to stain yeasts - Cryptosporidium
Modified Zn stain - Ova in stool
Concentrated iodine - Malaria
Thin blood film – Giemsa stain
patient with HIV cryptococcal meningitis was treated with caspofungin. Why is this is bad choice?
poor CSF penetration
too expensive
crypto resistant
contradicted in AIDS
Echinocandins are ineffective against cryptococcal
Another similar question exists with answer:
- cryptococcus is resistant to echinocandins as it does not contain 1,3 beta-d-glucan synthase
Cryptococcus does contain 1,3 beta-d-glucan synthase, but resistance is intrinsic by other means
Correct answer in that example is poor CSF penetration
Match the following organisms with the clinical pictures
Neisseria gonorrhea chlamydia trachomatis candida albicans treponema pallidum haemophilus ducreyi calymmobacterium granulomatis ureaplasma urealyticum trichomonaas vaginalis
- A 20 year old man presents with dysuria and uretheral discharge.A gram stained smear of a uretheral swab shows numerous pus calls but no organisms were detected
- A 34 year old man returning from Thailand where he had unprotected sex presents with a painless ulcer on his penis
- A 24 year old woman presents with arthritis and skin rash
- A 30 year old pregnant woman presents with itch and soreness and a thick white discharge
- A recent immigrant from Africa presents with a painful ulcer on his penis which bleeds on touch associated with tender enlarged inguinal lymph nodes, bacteriologic smear and culture were done but they were not helpful.
- A 20 year old man presents with dysuria and uretheral discharge.A gram stained smear of a uretheral swab shows numerous pus calls but no organisms were detected
Chlamydia trachomatis - A 34 year old man returning from Thailand where he had unprotected sex presents with a painless ulcer on his penis
treponema pallidum - A 24 year old woman presents with arthritis and skin rash
Neisseria gonorrhoea - A 30 year old pregnant woman presents with itch and soreness and a thick white discharge
trichomonas vaginalis - thick white discharge
candida albicans - usually cottage cheese
Bacterial Vaginosis - Gardnerella. Usually fishy smell - A recent immigrant from Africa presents with a painful ulcer on his penis which bleeds on touch associated with tender enlarged inguinal lymph nodes, bacteriologic smear and culture were done but they were not helpful.
haemophilus ducreyi
32wks pregnant lady with confirmed rubella.
Advice:
termination of pregnancy
child likely to be born with severe deformities
no risk of infection to fetus
risk of infection present, but deformities rare
risk of infection present, but deformities rare
No risk of documented abnormalities if infection occurs after 20 weeks
Woman develops rubella infection 8 days into pregnancy – what are the consequences for the foetus?
Miscarriage/ stillbirth
microcephaly
cardiac disease
visual problems e.g cataracts
Deafness
Pregnant woman is both HBV and HCV positive. Her newborn baby should receive the following treatment?
- Zidovudine
- Human Hep B immune globulin and full Hep B vaccination
- Human immune globulin only
- Interferon
Human Hep B immune globulin and full Hep B vaccination
Congenital infections.
- Toxoplasma gondii
- Chlamydia trachomatis
- Rubella
- Listeria monocytogenes
- CMV
- Treponema pallidum
- Parvovirus B19
- Pregnant woman had flu-like illness which is followed by a septic abortion. Autopsy of infant shows granulomas in liver
- A baby born with IUGR and hepatosplenomegaly
- A pregnant woman develops fetal hydrops on ultrasound
- A 2 month old infant presents with conjunctivitis and pneumonia
- Pregnant woman had flu-like illness which is followed by a septic abortion. Autopsy of infant shows granulomas in liver
Toxoplasma - A baby born with IUGR and hepatosplenomegaly
CMV - A pregnant woman develops fetal hydrops on ultrasound
Parvovirus B19 - A 2 month old infant presents with conjunctivitis and pneumonia
Chlamydia trachomatis
- A pregnant woman, 12 weeks gestation, is picked up at antenatal screening as HIV+ve. CD4 count is 500, viral load is 9000, the patient is asymptomatic and clinically well. Which of the following is the most correct?
a) Perform amniocentesis to detect whether the baby is infected
b) Do nothing and treat the baby after birth
c) Commence short-term antiretroviral therapy from the second trimester
d) A Ceasarian section is virtually unavoidable
Commence short-term antiretroviral therapy from the second trimester
Mother should then continue long term ARV - new evidence that should be on ARV regardless of CD4 count
Baby should get ARV e.g zidovudine
HBIG HBIG and hep B vaccination High dose hep B vaccination VZIG VZIG plus vaccination VZV vaccination HNIG Do nothing
- Baby of hep B eAg positive mother
- Neonate whose mother developes chickenpox 2 days post delivery
- Non-immune pregnant woman in contact with measles
- CRF patient, not currently on dialysis but who will be commencing dialysis in the near future
- Non-pregnant paediatric nurse, is not varicella immune, who has been looking after her mother with ophthalmic zoster
- Baby of hep B eAg positive mother
HBIG and hep B vaccination - Neonate whose mother develops chickenpox 2 days post delivery
VZIG - no cross-placenta antibody transfer. Give up to 7 days old - Non-immune pregnant woman in contact with measles
HNIG - CRF patient, not currently on dialysis but who will be commencing dialysis in the near future
High dose hep B vaccination - Non-pregnant paediatric nurse, is not varicella immune, who has been looking after her mother with ophthalmic zoster
VZV vaccination - occupational exposure
Pregnant woman 14 weeks, concerned re risk of toxoplasma and present to GP for testing. Results show weak positive IgM, positive IgG, predominantly
high avidity. What should she be advised?
Pregnancy likely to be severely affected and advise termination
Baby should receive sulphadiazine and pyrimethamine after delivery
Mother should receive sulphadiazine and pyrimethamine for duration of pregnancy
Mother should receive spiramycin for duration of pregnancy, baby is unlikely to be affected
spiramycin is recommended for women whose infections were acquired and diagnosed before 18 weeks gestation and infection of the fetus is not documented or suspected. Spiramycin acts to reduce transmission to the fetus and is most effective if initiated within 8 weeks of seroconversion. 40% of primary infection in pregnancy will infect foetus
Congenitally infected newborns are generally treated with pyrimethamine, a sulfonamide, and leucovorin for 12 months.
spiramycin is a macrolide
Pregnant woman tests positive for toxoplasma in pregnancy.
May present with flu-like illness, lymhadenopathy
What are risks to foetus?
Miscarriage
hydrocephalus
retinchoroiditis
Pregnant woman tests positive for toxoplasma in pregnancy.
What is treatment?
If diagnosed before 18 weeks gestation - Spiramycin to reduce risk of transmission.
USS/ choriamniocentesis - assess if baby affected. If affected, start pyremethamine/ sulphadiazine/ folinic acid for treatment (stop spiramycin)
Does toxoplasma infection always need treated?
Treat if immunocompromised, or pregnant
If otherwise well, after flu-like illness, toxoplasma will form cysts, and symptoms will resolve. Will only reactivate if become immunocompromised
Pregnant women 18 weeks, brings child who has
chickenpox to GP. Mother is
sure she has not had VZV. What should the GP do?
a. Issue prophylactic acyclovir
b. Issue VZIG
c. Test for VZV IgM
d. Test for VZV IgG
Test for VZV IgG ??
If non-immune, offer VZIG within 10 days
A pregnant woman returns from India and dies shortly after her return of an acute illness. Which of the following is most likely the cause?
Brucella Typhus Hep A Hep D Hep E
HEV
- A baby born to mother with primary CMV infection in pregnancy is detected to have 20000 copies/ml CMV in urine 2 days after birth. The most appropriate management strategy is:
a. Reassure and do nothing
b. Treat with IV Aciclovir for 2 weeks
c. Treat with IV Ganciclovir for 2 weeks
d. Refer for audiology assessment
e. Check CMV IgM in baby
Refer for audiology
If baby is well, and audiology/ brain imaging normal, then likely do not need to treat.
Aciclovir incorrect
Ganciclovir - should be for 6 months
IgM incorrect
A 24 week pregnant staff nurse sustains a needlestick from a HBSag positive patient who is HbEag positive. She has received 3 HBV immunisations in the past, and anti HBS level is < 10. The correct management is:
a. Give HBV vaccine dose and HBIG
b. Give infant HBIG at birth
c. Do nothing
d. Treat with Lamivudine
Give HBV vaccine dose and HBIG
Pregnant woman (36 weeks) suffers a rash illness, then presents to GP. Blood taken shows: Rubella IgG positive, IgM negative, Parvovirus IgG positive, IgM positive. What is the most likely outcome?
a. Normal healthy child
b. intra-uterine death
c. congenital rubella syndrome,
d. Hydropsfetalis
normal healthy baby
No risk of documented abnormalities if infection occurs after 20 weeks
A pregnant woman (32 weeks gestation) present with painful ulcer on her vagina. HSV2 PCR comes back positive. What would be you action?
Treat with acyclovir and treat baby
tell her all will be fine
treat with acyclovir and consider elective caesarian
measure HSV2 antibody to see if it is primary infection deliver by emergency section
treat with aciclovir, and consider elective caesarian section
