SBAs

Question 1

A 23 year old female presents to the GUM clinic complaining of new vaginal discharge which she describes as thick and malodorous. What is the most appropriate first-line investigation to reach a diagnosis?

Vaginal discharge sampling for pH and wet mount microscopy

urine for NAAT

urine for MCS

Vaginal swab for NAAT

blood for syphilis serology

Answer 1

vaginal discharge sampling for pH and wet mount microscopy

Question 2

MDR TB is resistant to:

RI

RE

RP

IE

IP

Answer 2

RI

Question 3

51-year-old female initially presented with a 2 hour history of sudden onset left arm and leg weakness with associated numbness and headache.

PMH: Hypertension, Sinusitis, Tuberculosis treated in 2009, hypertension

You are reviewing her on the post-take ward round with the following results:

HIV serology – reactive

MRI Head – 7 ring enhancing supratentorial lesions with perilesional oedeoma. There is no midline shift, tentorial herniation or hydrocephalus.

Most likely diagnosis:

Toxoplasmic encephalitis

Cryptococcal encephalitis

HIV encephalopathy

CMV encephalitis

Progressive multifocal leukoencephalopathy

Answer 3

Toxoplasmic encephalitis

Most common enhancing lesions would be:

• Toxoplasmic encephalitis – multiple lesions localised in the parietal or frontal lobes, thalamus or basal ganglia or at the corticomedullary junction, ring enhancement in >90%
• Primary CNS lymphoma – solitary or multiple lesions, majority of lesions enhance irregularly, lesions >4cm more likely to represent lymphoma vs infection

Other important infection in this patient would be to consider reactivation/reinfection of TB given history

Other infections are less common and often associated with evidence of disseminated disease: These include brain abscesses secondary to Staphylococcus, Streptococcus, Salmonella, Aspergillus, Nocardia, Rhodococcus, Listeria, unusual granulomatous collections, such as cryptococcomas, and syphilitic gummas.

Non-enhancing lesions:

• Progressive multifocal leukoencephalopathy, HIV encephalopathy, CMV encephalitis

Question 4

51-year-old female presents with a 2 hour history of sudden onset left arm and leg weakness with associated numbness and headache.

PMH: Hypertension, Sinusitis, Tuberculosis treated in 2009, hypertension

Her daughter also tells you she believes her mother was diagnosed with HIV 7 years ago during a visit to ED with an ankle sprain but refused further investigation or treatment.

Which investigation is most important to request urgently to assist in diagnosing this patient?

CT Head

MRI brain

HIV serology

LP with CSF sampling

FBC

Answer 4

CT Head

Question 5

Which of the following statements regarding hepatitis A virus is false?

Humans are the only known reservoir

Fulminant hepatic failure occurs in <1% of cases

Infection confers temporary immunity

Transmission is usually by the faecal-oral route

Maternal-fetal transmission has not been described

Answer 5

Infection confers temporary ommunity

Question 6

54 year old male presents with a cough productive of green sputum and fever. Chest X-ray shows consolidation at the right base. What is the most likely causative organism?

Haemophilus influenzae

Klebsiella pneumoniae

Mycoplasma pneumoniae

Staphylococcus aureus

Streptococcus pneumoniae

Answer 6

Steptococcus pneumoniae

The most common causative organism for community acquired pneumonia in the UK is Streptococcus pneumoniae.

Question 7

n 85 year old patient is admitted from a nursing home due to progressive drowsiness and confusion, of two days duration; the patient normally is bedbound following a stroke with an indwelling catheter. Examination reveals reduced conscious level but all four limbs are moving, with occasional eye opening, and a raised temperature of 37.8. Investigations reveal a CRP of 278. What is the most likely diagnosis and pathogen?

Meningitis with Streptococcus pneumoniae

Encephalitis with Herpes simplex

A non-infective diagnosis e.g. stroke

Urosepsis with Escherichia coli

Bloodstream infection with Staphylococcus aureus

Answer 7

urosepsis with E. coli

Question 8

Which of the following is the treatment of choice for severe malaria?

IV artesunate

Oral artesunate

IV quinine

Oral quinine

Oral Primaquine

Answer 8

IV artesunate is first line for the treatment of severe malaria in all patients. In uncomplicated falciparum malaria artemether-lumefantrine (Riamet) is used in all patients except those in the first trimester of pregnancy who are treated with quinine sulphate.

Question 9

hich of the following organisms is most likely to cause pelvic inflammatory disease?

Staphylococcus aureus

Group B streptococcus

Chlamydia trachomatis

Mycoplasma genitalium

Lactobacillus

Answer 9

In sexually active pre-menopausal women, Neisseria gonorrhoeae and Chlamydia trachomatis are the most commonly identified pathogens in pelvic inflammatory disease. PID in post-menopausal women is rare and may be caused by E. coli and colonic anaerobes.

Question 10

Aminoglycosides have good action against:

Aerobes

Anaerobes

Answer 10

Aerobes

Gram-negative – E. coli, proteus, Enterobacter, psudomonas

Gram-positive (in conjunction with beta-lactam) – staph aureus and coagulase negative staph, viridans streptococci, enterococcus

Question 11

19 year old male presents to the GUM clinic with a painless lesion on his penis. What is the most likely cause?

Herpes simplex virus

Syphilis (treponema pallidum)

Lymphogranuloma venereum (chlamydia trachomatis serovars L1-3)

Chancroid (Haemophilus ducreyi)

Granuloma inguinale (klebsiella granulomatis)

Answer 11

Herpes simplex virus is the most common cause of genital ulcers followed by syphilis, ulcers caused by HSV are usually painful whereas syphilitic ulcers are usually painless making syphilis the most appropriate answer.

Painful ulcers – HSV, chancroid

Painless ulcers – Syphilis, LGV and granuloma inguinale

Question 12

hich of the most common infective cause of fever in the returning traveller from the following list?

Dengue fever

Hepatitis A

Rickettsial infection

Malaria

Typhoid fever

Answer 12

malaria

Question 13

Which of the following ECG abnormalities does moxifloxacin cause:

Prolonged QTc

Flattened lateral T waves

Prolonged PR interval

Ventricular ectopics

Sinus tachycardia

Answer 13

prolonged QTc

Question 14

What percentage of patients are penicillin allergic?

<1%

1-10%

10-20%

20-30%

30-40%

Answer 14

1-10%

Allergic reactions occur in 1-10% of patients, anaphylactic reactions occur in <0.05%. Patients who are allergic to one penicillin will be allergic to all penicillins. Some individuals with penicillin allergy will have cross-sensitivity to cephalosporins so these should be used with caution and the decision to use will be based on the observed reaction and the necessity for the use of a cephalosporin.

Question 15

A 27 year old female presents to the GUM clinic complaining of frothy, purulent and malodorous vaginal discharge. What is the most likely cause?

Candida albicans

Neisseria gonorrhoeae

Chlamydia trachomatis

Trichomoniasis

Allergic vaginitis

Answer 15

Trichomoniasis presents with a purulent malodorous discharge. Vulvovaginal candidiasis presents with a white, cottage cheese discharge and pruritus.

Question 16

A 48 year old gentleman from Malaysia presents with right upper quadrant pain and is found to have deranged LFTs. A non-invasive liver screen is sent. How would you interpret the following results:

Hepatitis B virus surface Antigen: Negative

Hepatitis B surface Antibody: Positive

Hepatitis B core Antibody: Positive

Susceptible

Vaccinated

Past infection

Acute infection

Chronic infection

Answer 16

past infection

Question 17

68-year-old male who is HIV positive presents with a 2 week history of cough productive of green sputum, shortness of breath and fever.

Obs: HR 102, BP 126/73, RR 19, Sats 94% on RA but desaturates to 85% on mobilising to bathroom, Temp 38.7

Chest X-ray: Right upper zone opacification

HIV clinic bloods 3 months prior: CD4 count >200, viral load <20. Clinic notes report compliance with treatment.

What would be your immediate management:

Contact local HIV team for advice regarding switching HIV medications due to treatment failure

Contact local HIV team to review with a view to taking over patient’s care

Start treatment for pneumocystis pneumonia as per local guidelines

Start treatment for community acquired pneumonia as per local guidelines based on CURB 65 score

Send CD4 count and viral load and await results prior to further management decision

Answer 17

Start treatment for community acquired pneumonia as per local guidelines based on CURB 65 score

Question 18

A 31 year old patient presents in the emergency department at 38 weeks of pregnancy with a two day history of high fever, fainting, and abdominal pain. Examination reveals a temperature of 38C; heart rate of 120 bpm, respiratory rate of 30/minute and blood pressure of 80/60. She has blanching erythema across the abdomen and palms of the hands. She has not travelled recently and was well throughout pregnancy. Her husband is well but their 3 year old has been off nursery recently. Her GP had prescribed amoxicillin yesterday. What is the likely diagnosis? Where might you manage this patient?

Allergic reaction to amoxicillin

Viral exanthem caught from child

Toxic shock syndrome due to Staphylococcus aureus

Toxic shock syndrome due to group A Streptococcus

COVID19 in pregnancy

Question 19

Cutaneous lesions of Kaposi Sarcoma are usually:

Painful

Pruritic

Found on the upper arms

Not associated with necrosis of the overlying skin or underlying structures

Dark brown in colour

Answer 19

Not associated with necrosis of the overlying skin or underlying structures

Most commonly found on the lower limbs, face (nose), oral mucosa and genitalia. Occur in a range of colours due to their vascularity including pink, red, purple and brown.

Question 20

A 25 year old female presents to her GP complaining of increased vaginal discharge which is thin and has an unpleasant fishy odour. What is the most likely cause?

Candida albicans

Neisseria gonorrhoeae

Chlamydia trachomatis

Bacterial Vaginosis

Allergic vaginitis

Answer 20

BV

Question 21

Which of the following is not suggestive of severe malaria?

Low GCS

Hyperglycaemia

Parasitaemia >/= 2%

Hb <80

Pulmonary oedema

Answer 21

Hyperglycaemia

Hypoglycaemia is seen in severe malaria.

Other features include extreme weakness, seizures, AKI, acidosis, presence of schizonts on blood film, jaundice, DIC or spontaneous bleeding, and hypotension

Question 22

A 32-year old male intravenous drug user is brought into hospital with muscle pains, fatigue and a fever of 38.5. He has no other past medical history. On examination he has a new murmur and a Janeway lesion on his palm. He has grown staphylococcus aureus in one blood culture bottle. He has had a transthoracic ECHO which does not show any abnormality. Given the likely diagnosis which of the following is the most appropriate subsequent diagnostic investigation?

CT PET

Serial troponins

Transoesophageal ECHO

MR coronary angiogram

Percutaneous coronary angiogram

Answer 22

Transoesophageal ECHO

Question 23

A 51 year old previously fit man presents with a sudden onset of speech loss and history of one week of fever. On examination he has a loud pan systolic heart murmur and a left shoulder lesion. What is the most likely diagnosis?

Embolic stroke with coincidental influenza

Staphylococcus aureus sepsis with endocarditis and embolic phenomena

Septic arthritis

Acute rheumatic fever

Answer 23

The sudden onset of neurological signs on a background of fever should always prompt suspicion of embolic phenomena from endocarditis. The most common cause of endocarditis is now Staphylococcus aureus, which is also the most common cause of septic emboli that suppurate (form pus).

Question 24

What monitoring is recommended for patients treated with flucloxacillin?

Therapeutic drug levels

FBC

LFT

UEs

No monitoring required

Answer 24

No monitoring required

Question 25

A 53-year old female presents with a 1 week history of pain around her right eye and forehead associated with eyelid swelling and a vesicular rash (pictured below). She has a background of hypothyroidism but no other known medical conditions. What is the most likely causative organism? Varicella Zoster Virus Herpes simplex virus 2 Cytomegalovirus Staphylococcus aureus Streptococcus pyogenes

Answer 25

This is a case of herpes zoster ophthalmicus caused by infection and reactivation of varicella zoster virus within the **ophthalmic nerve** (the first division of the trigeminal nerve). This virus also causes chickenpox and shingles. When the rash is present on the **tip of the nose it is Hutchinson sign positive** and this implies involvements of the **nasociliary nerve** and raises concern for **serious ophthalmic complication – uveitis, keratitis and blindness**

Question 26

Extensively-drug resistant tuberculosis is resistant to rifampicin and isoniazid plus: Any fluoroquinolone Any fluoroquinolone and at least one of the injectable second-line drugs (e.g. amikacin) Ethambutol Ethambutol and pyrazinamide Ethambutol and any fluoroquinolone

Answer 26

Any fluoroquinolone and at least one of the injectable second-line drugs (e.g. amikacin)

Question 27

Which of the following is not a risk factor for severe malaria infection: Older age Age \<5 Immunocompromise Pregnancy Living in an endemic area

Answer 27

living in an endemic area

Question 28

23 year old male soldier presents to the doctor in his barracks. He has a cough, headache and fever. He also reports a rash pictured below Haemophilus influenzae Mycobacterium tuberculosis Mycoplasma pneumoniae Staphylococcus aureus Legionella pneumophilia

Answer 28

Mycoplasma pneumoniae

Question 29

A 19 year old male presents to the GUM clinic with a painful lesion on his penis. What is the most likely cause? Herpes simplex virus Syphilis (treponema pallidum) Lymphogranuloma venereum (chlamydia trachomatis serovars L1-3) Chancroid (Haemophilus ducreyi) Granuloma inguinale (klebsiella granulomatis)

Answer 29

HSV

Question 30

Clavulanic acid is an example of a: Beta-lactamase inhibitor Carbapenem Cephalosporin Beta-lactamase inducer Penicillin

Answer 30

b-lactamase inhibitor Given alongside amoxicillin (aka co-amoxiclav), it overwhelms the beta-lactamase enzymes

Question 31

Which of the following statements regarding hepatitis B virus is false? The rate of progression from acute to chronic Hepatitis B virus infection is around 90% for perinatally acquired infection Passive and active immunisation of the newborn within 12 hours of delivery reduces the risk of mother-to-child transmission by \>95% Around 70% of patients with acute hepatitis B virus infection have subclinical or anicteric hepatitis IgG hepatitis B core antibody persists in patients who recover from acute hepatitis B Hepatitis B e antigen is a late antigen that is generally considered to be a marker of previous infection

Answer 31

Hepatitis B e antigen is a late antigen that is generally considered to be a marker of previous infection

Question 32

Red legs This 85 year old man originally from Ethiopia has been complaining of severe pain in both legs when walking in the last 3 days. He normally walks with a frame but has recently refused to get out of bed. CRP is 360 but wcc is 6. What is the likely cause? Vascular gangrene Cellulitis Osteomyelitis Lymphatic filariasis Deep vein thrombosis

Answer 32

cellulitis The clue to this being cellulitis, is that the left leg (the purplish coloured limb) is very warm compared to the right leg. The dried slough on the surface of the leg indicates that there is considerable oedema that has been oozing probably for more than 3 days. However the duration of symptoms is not compatible with a longer standing condition such as osteomyelitis. The most likely organism is Streptococcus pyogenes

Question 33

A 48 year old gentleman from Malaysia presents with right upper quadrant pain and is found to have deranged LFTs. A non-invasive liver screen is sent. How would you interpret the following results: Hepatitis A virus IgM screen: Positive Hepatitis A virus IgG screen: Negative Susceptible Vaccinated Past infection Acute infection Chronic infection

Answer 33

Acute infection

Question 34

Beta-lactams: Inhibit bacterial protein synthesis Exhibit anti-cell wall activity Irreversibly bind to the 30S ribosomal subunits Irreversibly bind to the 50S ribosomal subunits Reversibly bind to the 30S ribosomal subunits

Answer 34

Beta-lactams inhibit the synthesis of the peptidoglycan layer in cell walls. Aminoglycosides and macrolides inhibit bacterial protein synthesis by irreversibly binding to the 30S and 50S ribosomal subunits, respectively Tetracyclines also prevent bacterial protein synthesis by binding reversibly to the 30S ribosomal subunit

Question 35

A 55 year old gentleman presents with confusion and agitated behaviour, he is unable to give any history and is not co-operative with neurological examination. CT Head is normal. CSF is TB PCR positive and TB Culture grows Mycobacterium tuberculosis Which of the following CSF results would you expect in this case: Raised opening pressure, raised WCC with predominantly PMNs, raised protein, low glucose Raised opening pressure, raised WCC with predominantly lymphocytes, raised protein, low glucose Normal opening pressure, raised WCC with predominantly lymphocytes, normal protein, normal glucose Raised opening pressure, raised WCC with predominantly lymphocytes, normal protein, normal glucose Normal opening pressure, raised WCC with predominantly PMNs, raised protein, low glucose

Answer 35

Raised opening pressure, raised WCC with predominantly lymphocytes, raised protein, low glucose

Question 36

A 45 year old homeless man with a history of problem drinking and recent imprisonment presented with a 6 week history of weight loss and fever. There was no cough, but a chest x-ray showed widespread nodularity. The patient was unable to produce a sputum sample. What would you do next? Commence quadruple anti-TB therapy as the diagnosis of miliary TB is clear Admit him to a sideroom and arrange a bronchoscopy to obtain samples Admit him to the general ward and arrange for induced sputum samples Commence community acquired pneumonia antibiotics to see if any response Arrange a CT chest abdo pelvis to determine extent of disease or malignancy Arrange for an ELIspot test to rule out TB as a diagnosis

Answer 36

This patient has several risk factors for drug resistant TB and the CXR is typical of miliary TB. Starting TB treatment without obtaining samples is a last resort and should only be done if there is immediate risk to the patient’s life from TB; samples may be the only way to identify drug resistance profile. Even if not actively coughing, miliary TB can be infectious and in the hospital environment, with immunosuppressed patients, it is sensible to manage this patient as though they may have MDR TB, in a negative pressure sideroom with respiratory precautions. An ELIspot test (which is a test of T cell recognition of a specific mTB antigen) is useful to confirm past TB exposure but cannot be used as a rule out tests, since patients with weight loss and frailty may often be unable to mount an interferon gamma response to the ELIspot antigen.

Question 37

A 28 year old man returned from Thailand 7 days ago where he had been on a beach holiday for 7 days, with some white water rafting, and developed a high fever of 40C 2 days ago with marked myalgia and feels quite unwell. He has blanching erythema on his back that could be sunburn but also more defined lesions on the leg and palate (as shown). CRP is elevated at 64 and ALT is elevated at 97. He has a wcc of 2 and a platelet count of 90. What is the most likely differential diagnosis? Would you give empirical antibiotics? ## Footnote Dengue fever Leptospirosis Meningococcal septicaemia Enterovirus infection Rickettsial illness (spotted fever)

Answer 37

Although dengue is the most likely, any of the above diagnoses were possible in this patient. In fact, this man actually had leptospirosis, although confirmation required serological tests for leptospirosis and negative PCR tests for dengue from a reference laboratory. These tests took 5 days to generate results. As life threatening bacterial infection could not be ruled out, it would be reasonable to give this patient an antibiotic active against meningococcal infection whilst awaiting blood culture results; ceftriaxone would also treat leptospirosis.

Question 38

A 32-year old male intravenous drug user is brought into hospital with muscle pains, fatigue and a fever of 38.5. He has no other past medical history. On examination he has a new murmur and a painless lesion on his hand pictured below. He has grown Staphylococcus aureus in one blood culture bottle. Which of the following minor criteria in Duke’s criteria has not been met? Fever **Immunological phenomena** Microbiological evidence Predisposition Vascular phenomena

Answer 38

Fever **Immunological phenomena** Microbiological evidence Predisposition Vascular phenomena

Question 39

Which of the following statements regarding hepatitis B virus is false? The rate of progression from acute to chronic Hepatitis B virus infection is 25% for adult acquired infection In high prevalence areas mother-to-child is the predominant mode of transmission Transmission from mother-to-child through breastfeeding is common Fulminant hepatic failure occurs in \<1% During acute infection Hepatitis B core antibody is predominantly of IgM class

Answer 39

The rate of progression from acute to chronic Hepatitis B virus infection is 25% for adult acquired infection

Question 40

Which of the following is not a recognised adverse effects of aminoglycoside antibioitcs (e.g. amikacin, gentamicin): Nephrotoxicity Ototoxicity Neuromuscular paralysis Nausea and vomiting Hyponatraemia

Answer 40

Hyponatraemia