Infectious Diseases

Question 0

which of the following is the most useful in planning the management of hep c in a patient found to have detectable HCV RNA in blood?
A ALT
B IFNa resistance testing
C HCV RNA quantification
D HCV genotype
E Serum HCV IgG level

Answer 0

Genotype determines duration of treatment

type 1 harder to treat

Question 1

A 20 yr old injecting drug user attends A&E with jaundice. He is admitted to hospital and has the following results:
A Hep A total antibody positive
B Hep B surface ag positive
C Hep B anti-core IgM +
D Hep C IgG +
E Hep C RNA +
Which test indicates the cause of the jaundice?
A hep A total antibody
B Hep B surface antigen
C Hep B anti-core IgM
D Hep C IgG
E Hep C RNA

Answer 1

C

A - have acute hep A, or had hep A (IgG), or vaccinated
B - hep B infection but doesnt tell you what the virus is doing
C - IgM only comes up acutely, then goes down
D - only + after an infection
E - + the whole way through an infection

Question 2

25 year old woman
HBsAg +
HBeAg - 
Hbe Ab +
HB c AB +
ALT 3-4x normal
HB core IgM -
Husband developed acute hep B 2 wks ago
Next investigation?
A Hep D testing
B hep B DNA quantification
C Hep C testing
D liver USS
E alpha fetoprotein

Answer 2

B
pre-core mutation - stop producing E antigen despite the fact that virus is replicating
B is correct as measures viral replication directly
(alpha fetoprotein is a marker for HCC)

Question 3

35 yr old homosexual man 3 wk hx of fever and malaise. O/E general lymphadenopathy and splenomegaly. Unprotected sex with a number of partners. No rash or mucosal ulceration. HIV Ab test is -ve. A paul-bunnell test is weakly +. The LFTs are mildly deranged. WHich one of the following is the most likely diagnosis?
A primary HIV infection
B secondary syphilis
C acute hep A
D acute EBV
E acute CMV

Answer 3

E

CMV has a lower prevalence (~50%) therefore more people are susceptible to having an acute infection than EBV (~90%) prevalence

Glandular fever like illness

Commonly LFTs are deranged

A is possible but hasnt had antigen test (could be a serum conversion problem) but is unlikely

Question 4

25 yr old woman who is 12 wks pregnant has a 3 yr old child who develops typical chicken pox. mother doesnt recall having chicken pox. she is entirely well. What would u advise?
A avoid further contact with the child
B test the mother for varicella zoster IgG
C take acyclovir as prophylaxis
D receive varicella zoster immune globulin (ZVIG) urgently
E consider termination of pregnancy

Answer 4

B - 90% are immune

as 10 day window to give ZVIG so it is not urgent

Question 5

which one of the following viruses is assoc with the accompanying malignancy?
A HHV8 - body cavity lymphoma in HIV
B HTLV1 bronchial carcinoma
C HCV hairy cell leukaemia
D CMV cholangiocarcinoma
E HPV osteosarcoma

Answer 5

A

B - T cell lymphomas
C - HCC
D - no malignancy
E cervical malignancies

Question 6

16 yr old boy develops severe tonsillitis prevents him from swallowing his own saliva. O/E symmetrically enlarged inflamed tonsils. Concerns airways will become compromised
Management
A amoxicillin and metronidazole
B IV hydrocortisone
C oxygen-helium mix
D 
E

Answer 6

Iv hydrocortisone

alternatively gargle aspirin

Question 7

20 yr olf with 4day hx of malaise, conjunctivitis and cough. Develops maculo papular rash on face and upper trunk. 
A parvovirus B19
B measles
C rubella
D
E

Answer 7

measles

conjunctivitis is the clue - typical of measles

Question 8

18 yr old - no childhood vaccinations. fevers meningism orchitis unilateral parotitis. 
A urine dip
B blood cultures
C FBC
D serum IgM
E CSF bacterial culture

Answer 8

mumps
meningism = photophobia, nuchal rigidity and headache
facial swelling and testicular swelling + rash are typical of mumps
D

Question 9

outbreak of D&V. Bacterial stool cultures all negative. Likely agent?

Answer 9

norovirus

Question 10

25 yr old gives birth to a well baby with unilateral microphthalmia. She had a rash during the 2nd trimester. Causative agent?
syphilis
VZV
rubella
CMV
parvovirus B19

Answer 10

VZV

unilateral skin involvement

Question 11

which of these are not live vaccines?
Measles
Mumps 
Rubella
Diphtheria
BCG
hepatitis A
yellow fever
oral typhoid
VZV
meningococcal
parenteral polio (salk)

Answer 11

Diphtheria, Hep A, meningococcal, parenteral polio (salk)

Live vaccines: measles, mumps and rubella, 
   BCG
   Yellow fever
   oral typhoid
   oral polio (sabin)
VZV

Question 12

air steward who is HIV +. He has just started ARVs. CD4 count 180x106/l. Which of the following live vaccines is there the best evidence of a major adverse effect?
yellow fever vaccine
Hep B
Hep A
rabies
Tetanus

Answer 12

Yellow fever vaccine as is a live vaccine

Question 13

a man goes to thailand for 2 wks. 4 wks later he develops a febrile illness. diagnosis?

Answer 13

HIV seroconversion illness

major differential for a seroconversion illness: secondary syphilis
similar symptoms and incubations period

Question 14

holiday in Spain in hotel. 4 days after develops a fever. Diagnosis

Answer 14

legionella

Question 15

man goes to oklahoma and camps. develops febrile illness with a rash. Diagnosis

Answer 15

Rickettsia

Rocky Mountain spotted fever disease - tick born disease

Question 16

man goes to connecticut (eastern USA) - febrile illness. Diagnosis

Answer 16

Lyme’s disease

Anywhere with deer (e.g. forests)

Question 17

25 yr old woman - fever 40 degrees, BP 80/40. ITU - and recovers following broad spectrum antibiotics. Blood cultures -ve. 10 days later widespread desquamation
staph aureus
Lyme disease
dengue fever
measles
strep pneumococcus

Answer 17

staph aureus

toxic shock syndome

Question 18

25yr old woman malaise, fever, profuse vomiting, mild diarrhoea. erythematous rash

Answer 18

toxic shock syndrome

Question 19

splenectomy 7yrs earlier. Presents with sepsis. BP 80/60 temp 40. Diagnosis?
A staph aureus
B E. coli
C Capnocytophaga canimorsus
D Eikenella corrodens
E influenza

Answer 19

strep pneumo would be best answer an capsulated bacteria

capnocytophaga canimorsus
assoc with dog bites
higher risk of sepsis

Question 20

35 yr old 2 wk hx of fever. echo reveals vegetation on mitral valve. Blood culture + (gram - rod). not a IVDU
strep bovis
pseudomonas aeruginosa
treponema pallidum
acinebacter sp
eikenella corrodens

Answer 20

eikenella corrodens

acinebacter sp - doesnt cause endocarditis
trepnema - syphilis - not on blood cultures

Question 21

endocarditis. Blood cultures + for strep viridans. treated with IV benzylpenicillin and gentamicin.
which requires urgent surgical intervention?
Tricuspid endocarditis causing incompetence
Increasing PR interval
Elevated CRP 24hrs after
splinter haemorrhages

Answer 21

rupture of aortic root abscess is a risk

Increasing PR interval on ECG

Question 22

35 yr old. previously well. CAP and mild watery diarrhoea. failed to improve after 3 days amoxicillin given by GP. temp 40 degrees, headache, slightly confused. no evidence of meningitis. Peripheral WCC on upper limit normal and Na 125mmol/l. 2 other members of office are ill with similar symptoms. 
Mycoplasma pneumo
legionella pneumo
influenza A
chlamydia pneumo
penicillin resistant strep pneumo

Answer 22

Legionella- severe disease, v low sodium
2 other people in office - air conditioning spread
Not transmissible through people

whereas mycoplasma (overcrowded conditions), less severe, low sodium but not as low. unlikely to pass to people in office.

Question 23

17yr old. Fever confusion hypotension (75/50) rapidly spreading purpuric rash.
obtain urgent CT scan lumbar puncture
give high dose iv steroids
administer erythromycin to penicillin allergic contacts
reverse barrier nurse for 24 hrs
take an EDTA blood sample for PCR

Answer 23

E - diagnostic gold standard test
meningococcal septicaemia

dont do LP - as no platelets so patient will bleed out
dont give IV steroids as dont give in absence of antibiotics
penicillin allergic contacts give rifampicin, or cipro

Question 24

45 yr old. fever and meningism. CSF opening pressure 18cm, protein 0.8g/l, glucose 3.5, 560 neutrophils. 
Herpes simplex type 2
treponema pallidum
listeria monocytogenes
borrelia burgdorferi
acute HIV seroconversion illness

Answer 24

Listeria

acute bacterial meningitis - neutrophilic

HIV & treponema & HSV - wont raise neutrophils as viruses - cause lymphocytic meningitis

Question 25

78yr old alcoholic with 2month hx cough and haemoptysis, fever, night sweats and weight loss. CXR extensive bilateral apical cavitation. treated for TB. Complications
acute psychosis
impaired vision
drug-induced hepatitis
development of multi-drug resistance
gout

Answer 25

drug induced hep

Question 26

27 yr old russian - sputum strongly smear positive for AAFB> Tb diagnosed 2 yrs ago. has had a variety of short courses of treatment. You plan to admit to hosp. Management?
admit to positive pressure side room
start immediate treatment with RIPE (isoniazid, pyranzinamide, ethambutol, rifampicin)
start amoxicillin and clarithromycin
perform PCR for rifampicin-resistance gene on sputum
start immediate treatment with isoniazid, pyranzinamide, rifampicin

Answer 26

D - rifampicin resistance alone is v rare (so usually a hallmark of multi-drug resistant TB)

A - will blow TB around hospital
Normal TB treatment (RIPE) will not work & will cause resistant strains to thrive and induce resistance to drugs he was susceptible to

Question 27

30 yr old indian woman. nodular rash, loss of eyebrows and burns on hands. ulnar nerves are thickened and tender. Skin biopsy presence and numerous AFBs. Management
Prednisolone, clofazimine, rifampicin, dapsone with close outpatient follow up
treat with prednisolone, clofazimine, rifampicin and dapsone and admit for resp isolation
treat with pred isoniazid and dapsone with close outpatients follow up
resp isolation

Answer 27

diagnosis is leprosy \
A - rifampicin is effective in leprosy but isoniazid is not (not D)
resp isolation is wrong as not a resp disease

Question 28

40 yr old with sudden collapse. tick bite 3 month previously in a forest. bite was followed by a prolonged rash. Likely cause of collapse
meningo encephalitis
acute Bell’s palsy
stokes-adam (AV heart block)

Answer 28

stokes adam