infectious diseases

Question 1

Retro-orbital headache, fever, facial flushing, rash, thrombocytopenia in returning traveller →

Answer 1

?dengue

Question 2

Patients with an uncertain tetanus vaccination history should be given ____

Answer 2

for tetanus prone and high-risk wounds: reinforcing dose of vaccine + tetanus immunoglobulin

Question 3

Pneumonia, peripheral blood smear showing red blood cell agglutination →

Answer 3

mycoplasma pneumonia

Question 4

prophlyactic abx for animL BITE?

Answer 4

co-amoxiclav

Question 5

travel Hx, prolonged fever, abdominal pain, constipation, ‘rose’ spots, bradycardia →

Answer 5

?typhoid fever

Question 6

Abx recommended for pyelonephritis?

Answer 6

cephalosporin
quinolone

Question 7

Resp Abx
1. CAP
2. Atypical pneumonia
3. HAP

Answer 7

1. CAP: amoxicillin
2. Atypical pneumonia: clarithromycin
3. HAP: co-amoxiclav if within 5 days of admission, piperacillin with tazobactam if after 5 days

Question 8

UTIs Abx
1. LUTI
2. Pyelonephritis
3. Prostatitis

Answer 8

1. LUTI: trimethoprim/nitrofurantoin/amoxicillin
2. Pyelonephritis: ceftazidime/ciprofloxacin
3. Prostatitis: quinolone/trimethoprim

Question 9

Abx for cellulitis near eyes or nose?

Answer 9

Co-amoxiclav

Question 10

Otitis media vs otitis externa - Abx?

Answer 10

media: amoxicillin
externa: flucloxacillin

erythromycin for both if penicillin allergic

Question 11

Abx for throat infections/sinusitis

Answer 11

phenoxymethylpenicillin (PenV) (erythromycin if allergic to penicllin)

Question 12

STI Abx
1. Gonorrhea
2. Chlamydia
3. PID
4. Syphilis
5. BV

Answer 12

1. Gonorrhea: ceftriaxone
2. Chlamydia: doxycycline
3. PID: doxycycline + ceftriaxone + metronidazole
4. Syphilis: benathine benzylpenicillin (doxy/erythromycin if allergic)
5. BV: metronidazole

Question 13

Campylobacter enteritis Tx?

Answer 13

clarithromycin

Question 14

___________ is a mass-like fungal vall that colonises an existing lung cavity (like TB, lung cancer, cystic fibrosis). _____ sign on Xray.

Answer 14

aspergilloma
crescent sign

Question 15

undercooked or reheated rice is most associated with ___________.

Answer 15

bacillus cereus

Question 16

most common causative organism in cellulitis

Answer 16

strep pyogenes

Question 17

classification system used for cellulitis

Answer 17

Eron system

Question 18

painful genital ulcers with sharply defined, ragged borders + unilateral painful inguinal lymph node =

Answer 18

chancroid
tropical disease caused by haemophilus ducreyi

Question 19

classifying bacteria

Answer 19

1. Gram-positive cocci: all strep, staph
2. Gram-negative cocci: neisseria meningitidis, gonorrhoeae
3. Gram-positive rods: ABCDL
   Acintomyces
   Bacillus anthracis
   Clostridium
   Diptheria
   Listeria
4. Everything else is gram-negative rod:
   E.Coli
   H.influenzae
   Pseudomonas
   Salmonella
   Shigella
   Campylobacter

Question 20

‘ground glass’ hepatocytes on light microscopy is associated with

Answer 20

chronic hepatitis (secondary to hep B infection)

Question 21

__________is the second line choice antibiotic for MRSA, after vancomycin or teicoplanin

Answer 21

Linezolid

Question 22

Latent tuberculosis treatment options:

Answer 22

3 months of isoniazid (with pyridoxine) and rifampicin, or
6 months of isoniazid (with pyridoxine)

Question 23

Pt tests positive for MRSA before elective surgery - Tx?

Answer 23

Nasal mupirocin + chlorhexidine for the skin

Question 24

Positive non-treponemal test + negative treponemal test is consistent with a

Answer 24

false-positive syphilis result

Question 25

HIV, neuro symptoms, single brain lesions with homogenous enhancement -

Answer 25

CNS lymphoma

Question 26

Fever, rash, chills and headache occurs following antibiotic administration for syphilis - Tx?

Answer 26

Jarisch-Herxheimer reaction JHR generally requires supportive management with antipyretics and resolves within 24 hours.

Question 27

____________ - stains with India ink

Answer 27

Cryptococcus neoformans Streptococcus pneumoniae would have a gram-positive stain while Neisseria meningitidis would have a gram-negative stain. Mycobacterium tuberculosis would have a Ziehl-Neelsen (acid-fast) stain. In toxoplasmosis, the head CT usually shows single or multiple ring enhancing lesions, and mass effect may be seen.

Question 28

______________ is an alternative to metronidazole for patients with bacterial vaginosis

Answer 28

Topical clindamycin

Question 29

If a combined HIV test is positive

Answer 29

it should be repeated to confirm the diagnosis

Question 30

HIV testing

Answer 30

1. HIV antibodies - people develop HIV ab 4-6 week after expsoure - comprises ELISA + confirmatory Western Blot assay 2. p24 Antigen - poitive from 1-4 weeks after exposure 3. Combined test (p24 and HIV ab) - gold standard - if positive, repeat test - you can test HIV RNA levels at the same time Test for HIV in asymptomatic Pts 4 weeks after possible exposure. If negative, repeat in 12 weeks. Start post-exposure prophylaxis within 72h of exposure.

Question 31

Disseminated gonococcal infection triad -

Answer 31

tenosynovitis, migratory polyarthritis, dermatitis Neisseria gonorrhoea

Question 32

HIV seroconversion occurs when?

Answer 32

from 3-12 weeks

Question 33

Which abx is C/I in long QR syndrome?

Answer 33

Clarithryomycin

Question 34

what can cause false positive syphillis VDRL/RPR?

Answer 34

'SomeTimes Mistakes Happen' (SLE, TB, malaria, HIV)

Question 35

Tx for typhoid fever?

Answer 35

Ceftriaxone

Question 36

Which Abx is ecoli sensitive to extended spectrum beta-lactamase (ESBL)-producing Escherichia coli

Answer 36

meropenem ESBLs exhibit hydrolytic activity against both penicillins and cephalosporins.

Question 37

HIV, neuro symptoms, widespread demyelination -->

Answer 37

progressive multifocal leukoencephalopathy

Question 38

neuro complictions of HIV: 1. behavioural changes and speech, motor and visual impairment. MRI is the imaging modality of choice, identifying multifocal non-enhancing lesions, which represent widespread demyelination. 2.cognitive decline, behavioural changes and motor impairment. CT shows cortical and subcortical atrophy. 3. meningism, nausea/vomiting, seizures and focal neurological deficits. Lumbar puncture often shows a high opening pressure and cerebral oedema may be seen on CT. 4. This is associated with the Epstein-Barr virus and presents with various symptoms depending on lesion location. CT often shows a single brain lesion with homogenous enhancement. 5. This accounts for around 50% of cerebral lesions in patients with HIV and often presents with constitutional symptoms, headache and confusion. CT commonly shows multiple ring-enhancing lesions.

Answer 38

Progressive multifocal leukoencephalopathy (PML) AIDS dementia Cryptococcus infection Primary CNS lymphoma Toxoplasmosis

Question 39

Mx of primary CNS lymphoma Mx of toxoplasmosis

Answer 39

Treatment generally involves steroids (may reduce tumour size), chemotherapy (e.g. methotrexate) and whole-brain irradiation. Surgical may be considered for lower grade tumours. Management is with sulfadiazine and pyrimethamine.

Question 40

swimmers itch + eosinophilia

Answer 40

schistosomiasis

Question 41

Immunocompromised patients with toxoplasmosis are treated with

Answer 41

pyrimethamine plus sulphadiazine

Question 42

Cause of false negative Mantoux tests include and are not limited to:

Answer 42

TB AIDS Long-term steroid use Lymphoma Sarcoidosis Extremes of age Fever Hypoalbuminaemia Anaemia

Question 43

If a patient has had 5 doses of tetanus vaccine, with the last dose < 10 years ago,

Answer 43

they don't require a booster vaccine nor immunoglobulins, regardless of how severe the wound is

Question 44

which abx lowers seizure threshold

Answer 44

Ciprofloxacin lowers the seizure threshold

Question 45

Epstein-Barr virus may result in which blood test abnormality

Answer 45

neutropaenia

Question 46

most common reason for recurrent tonsilitis in a young person

Answer 46

glandular fever

Question 47

Ciclosporin side-effects:

Answer 47

everything is increased - fluid, BP, K+, hair, gums, glucose