Mock Infectious Diseases Module 3

A 35-year-old man is undergoing a dental procedure involving manipulation of gingival tissue.

Which of the following poses the strongest indication for antibiotic prophylaxis against infective endocarditis?

Which of the following is the most common fungal infection in immunocompromised patients?

Which of the following typically carries the highest mortality rate among immunocompromised patients with invasive fungal infection?

A 26-year-old man returned from the Solomon Islands one week ago and presents with a two-day history of fever, rigors, headache, malaise, nausea, vomiting, dry cough, mild arthralgia, and backache. He denies dyspnoea, diarrhoea, neck stiffness, or photophobia. He took doxycycline as malaria prophylaxis. On day 3 he develops a truncal and facial rash with petechiae over the lower limbs.

Which of the following is the most likely diagnosis (assuming malaria has been excluded)?

For which of the following conditions is there the best evidence of benefit from adjunctive systemic corticosteroids?

Which Plasmodium species causes the most virulent form of malaria?

A 35-year-old man returned from Africa, taking mefloquine prophylaxis until two weeks after return. Eight weeks later he presents with fever and rigors. Blood film shows Plasmodium vivax in 1% of red cells.

Which is the most appropriate management (assuming G6PD-normal)?

A 15-year-old girl who emigrated from Zimbabwe 18 months ago presents with a three-month history of recurrent painless terminal gross haematuria. Several midstream urine specimens show numerous red cells, white cells, and 2+ protein on dipstick, without significant bacterial growth. Renal function and ultrasound are normal. Urine microscopy shows terminal-spined ova.

What is the most appropriate treatment?

A medical student returns from an elective in rural Thailand with an acute febrile illness and myalgia. He develops hypotension, acute kidney injury, interstitial pneumonitis, aseptic meningitis, hepatosplenomegaly, and jaundice.

Which of the following is the most appropriate treatment?

 A 15-year-old teenager presents with a two-day history of severe right iliac fossa pain, preceded by vomiting, high fever, and diarrhoea. He is tender in the right iliac fossa while the remainder of the examination is unremarkable.

Which organism is most likely responsible?

The most common cause of diarrhoea in an adult traveller to a developing country is?

A 22-year-old man presents with ten days of fever beginning three weeks after visiting family in Bangladesh, with headache, abdominal pain, anorexia, dry cough, and myalgia.

Temperature 40.5°C, pulse 92/min, BP 120/65 mmHg; chest clear; generalised abdominal tenderness without peritonism.

Hb 140 g/L, WCC 3.5 × 10⁹/L, repeatedly negative malaria films; renal function, electrolytes, liver enzymes, and chest X-ray normal.

What is the most appropriate treatment?

A 50-year-old man has a two-month history of frequent, small-volume stools with cramps and flatulence since returning from Southeast Asia.

The empirical treatment most likely to be successful is?

A 25-year-old man presents six weeks after travel to central Africa with fever, chills, and rigors. Stool examination is positive for Entamoeba histolytica, and ultrasound reveals a 7.5 cm liver abscess.

The most appropriate next step is?

Which of the following is least likely to be associated with a rash?

Which of the following is the most life-threatening fungal infection typically requiring urgent surgical debridement of devitalised tissue?

A 72-year-old patient receiving total parenteral nutrition develops fever, and blood cultures grow Candida krusei. In addition to initiating appropriate antifungal therapy with an echinocandin, which of the following management strategies is most appropriate?

A 58-year-old man is undergoing induction chemotherapy for newly diagnosed acute myeloid leukaemia (AML). Two weeks later, he develops profound neutropenia with persistent fever despite broad-spectrum antibacterial therapy.

Which opportunistic fungal infection is most likely in this setting?

A previously well 18-year-old man presents with a three-month history of cough. Temperature 37.8°C, with reduced air entry in the right upper lobe. He has no unwell contacts and last travelled to the Philippines three years ago.

Chest X-ray shows right upper lobe consolidation with possible cavitation. Which is the most appropriate initial treatment?

Which of the following is the most appropriate initial treatment?

Which of the following is most directly predictive of multidrug-resistant TB (MDR-TB)?

Which of the following strategies is most effective in reducing the population-level incidence of multidrug-resistant Mycobacterium tuberculosis (MDR-TB)?

A 60-year-old man is diagnosed with infective endocarditis caused by Streptococcus bovis (Streptococcus gallolyticus), successfully managed.

Given this diagnosis, which malignancy is he most likely predisposed to?

Which of the following is NOT a typical indication for surgery in native valve infective endocarditis?

Native valve endocarditis in a person who injects drugs is most likely caused by?

A 15-year-old girl underwent a T-cell-depleted unrelated bone marrow transplant for relapsed acute lymphoblastic leukaemia. Recovery is complicated by slow neutrophil engraftment, grade 3 acute graft-versus-host disease requiring high-dose methylprednisolone, and persistent fevers.

A CT chest at day +50 shows nodular lesions with surrounding ground-glass (halo sign).

Which pathogen is most likely responsible?

A 50-year-old man presents with severe community-acquired pneumonia. He has a history of immediate hypersensitivity to penicillin.

What is the most appropriate antibiotic therapy?

A 40-year-old man with severe MRSA pneumonia is treated with vancomycin, dosed to achieve an area-under-the-curve to minimum inhibitory concentration ratio (AUC/MIC) of approximately 400–600.

Despite documented attainment of this pharmacodynamic target, he continues to deteriorate with persistent hypoxia, fever, and ongoing positive cultures. The vancomycin MIC is 2 mg/L.

What is the most appropriate next step?

Fever following travel to sub-Saharan Africa

A 34-year-old man presents with a 4-day history of fevers, rigors, headache and myalgia. He returned 10 days ago from a 3-week trip visiting relatives in Nigeria. He took atovaquone-proguanil prophylaxis intermittently but admits missing several doses.

On examination he is febrile (39.2°C), tachycardic (heart rate 108/min) and appears unwell. There is mild scleral icterus and splenomegaly. There is no rash or lymphadenopathy.

Investigations:

Which is the most appropriate initial investigation to confirm the diagnosis?

A 29-year-old woman presents with high fevers 12 days after returning from Papua New Guinea. Blood films confirm Plasmodium falciparum with a parasitaemia of 6%.

She is drowsy (Glasgow Coma Scale 13), with a respiratory rate of 26/min and oxygen saturation 93% on room air.

Investigations:

Which is the most appropriate first-line antimalarial treatment?

A 26-year-old woman presents with 5 days of high fever, severe retro-orbital headache, myalgia and arthralgia. She returned 6 days ago from a 2-week holiday in Thailand and Bali. She reports a widespread blanching maculopapular rash that appeared on day 4.

On examination she is febrile (39.4°C), with a fine erythematous rash and mild conjunctival injection. There is no eschar, jaundice or lymphadenopathy.

Investigations:

Which is the most likely diagnosis?