1. RACP ID Questions
M Armstrong
25/11/2015

2. Preparing for exams… Questions, Questions, Questions… Old RACP (including recall), MKSAP, Harrison’s Infectious diseases images:

3. Not releasing old questions… But 2004-2008 available (and some earlier)

4. Q
Which one of the following is least likely to be associated with a reduced risk of mother-to-child transmission of human immunodeficiency virus (HIV)?
A. Maternal plasma HIV RNA concentration (viral load) <1000 copies/mL.
B. Maternal CD4+ T cell count >500 cells/mm3.
C. Maternal antiretroviral therapy.
D. Avoidance of breastfeeding.
E. Elective Caesarean delivery.

5. Answer: B. CD4 count. Most cases of vertical transmission occur in labour. But can also occur antepartum and postpartum. Overall risk between 25-30%. Risk of perinatal transmission increases with increasing maternal HIV RNA levels, the viral load is the predominant risk factor for transmission.

6. Q
A 37-year-old man presents to the emergency department with symptoms of meningitis. Gram stain of the cerebrospinal fluid reveals the presence of gram-negative diplococci.
His 12-week pregnant partner should receive which one of the following as prophylaxis?
A. Ciprofloxacin.
B. Ceftriaxone.
C. Penicillin.
D. Meningococcal vaccine.
E. Erythromycin.

7. Answer: B. Ceftriaxone. Ciprofloxacin Class B3 in pregnancy (Ceftriaxone B1).
Category B1
Drugs which have been taken by only a limited number of pregnant women and women of childbearing age, without an increase in the frequency of malformation or other direct or indirect harmful effects on the human fetus having been observed. Studies in animals have not shown evidence of an increased occurrence of fetal damage.
Category B3
Drugs which have been taken by only a limited number of pregnant women and women of childbearing age, without an increase in the frequency of malformation or other direct or indirect harmful effects on the human fetus having been observed. Studies in animals have shown evidence of an increased occurrence of fetal damage, the significance of which is considered uncertain in humans.

8. Q
A 32-year-old man has a splenectomy following a motorcycle accident. Which of the following organisms is most likely to cause overwhelming post-splenectomy infection in this man?
A. Streptococcus pneumoniae.
B. Neisseria meningitidis.
C. Staphylococcus aureus.
D. Escherichia coli.
E. Haemophilus influenzae.

9. Answer: A. Streptococcus pneumoniae. Isolated in 50-70% of cases
Answer: A. Streptococcus pneumoniae. Isolated in 50-70% of cases. At risk of severe sepsis from encapsulated organisms.

10. Q
Angiostrongylus cantonensis, the rat lung worm, is acquired by eating the intermediate snail or slug host or contaminated vegetables.
Which of the following clinical syndromes is most characteristic of this parasite?
A. Haematuria.
B. Rectal bleeding.
C. Ascending cholangitis.
D. Eosinophilic meningitis.
E. Visceral larva migrans.

11. Answer: D. Eosinophilic meningitis. Angiostrongylus cantonensis
Answer: D. Eosinophilic meningitis. Angiostrongylus cantonensis. Most common cause of eosinophilic meningitis. South East Asia and Pacific Basin. Humans are incidental hosts. Infective larvae in land snails/ slugs. Larva migrate to brain- and die in CNS but cause marked eosinophilic inflammation and haemorrhage, usually 3-35 after contamination. Eosinophils >20% on LP. Treatment- supportive/ steriods.

13. Q
A 26-year-old man presents with a two-day history of fevers, rigors, headache, malaise, nausea and vomiting, dry cough, mild arthralgia and backache. He reports no shortness of breath, diarrhoea, neck stiffness or photophobia. He reports that he returned from a diving trip to the Solomon Islands seven days ago. He had taken doxycycline regularly as malarial prophylaxis. On day 3 after the onset of the illness he develops a rash over his trunk (shown below) and face. A petechial rash was noted on his lower limbs.

15. Q5. 2004 Which of the following is the most likely diagnosis?
A. Malaria.
B. Dengue fever.
C. Typhoid fever.
D. Q fever.
E. Measles.

16. Answer: B. Dengue fever. Fever in returned traveler… Related to travel or not. Fever with localizing features. Increasing resistant organisms. Dengue 2nd after malaria in travel related systemic febrile illness. Flavivirus. Incubation period 3-8 days. Vector Aedes aegypti. 4 serotypes- 2nd infection with different serotype leading to dengue HF, septic shock. Diagnosis via PCR/ serology. Treatment supportive.

18. Q
The most common cause of diarrhoea in an adult traveler to a developing country is:
A. Shigella species.
B. Salmonella species.
C. Campylobacter species.
D. enterotoxigenic Escherichia coli.
E. Giardia lamblia.

19. Answer: D. Enterotoxigenic Escherichia coli CDC: “The most common causative agent isolated in countries surveyed has been enterotoxigenic Escherichia coli (ETEC). ETEC produce watery diarrhea with associated cramps and low-grade or no fever”

20. Q
A 56-year-old forestry worker develops a widespread rash involving the trunk and lower limbs two weeks following a tick bite. He is generally unwell with myalgias, fevers, headache and anorexia. The rash is papular, non-blanching and not itchy, and is shown below.

22. Q7. 2005 What is the most appropriate management?
A. Treat expectantly.
B. Doxycycline.
C. Ciprofloxacin.
D. Ceftriaxone.
E. Phenoxymethylpenicillin (penicillin V).

23. Answer: B. Doxycycline. Rickettsiae- rod shaped gram negative obligate intracellular. Tick vectors- Ixodes sp. Rickettsia australis- Queensland Tick Typhus (east coast) Orientia tsutsugumushi- Scrub Typhus (northern Queensland) Rickettsia honei sub sp. marmionii- Australian Spotted Fever (east coast/ south east) Fever, rash, eschar, myalgia, headache..

24. Q
A 22-year-old man presents with ten days of fever that started three weeks after returning from visiting family in Bangladesh. He complains of headache, abdominal pains, anorexia, a dry cough and generalized muscular aches and pains.
On examination he looks ill. Temperature is 40.5C, pulse 92/minute and blood pressure 120/65 mm Hg. On auscultation he has a clear chest. There is generalised abdominal tenderness without rigidity or guarding.
Blood tests show:
Haemoglobin 140 g/L [ ] White cell count 3.5 x 109/L [ ]
Blood films are repeatedly negative for malaria. Renal function, electrolytes, liver enzymes and chest X-ray are normal.
What is the most likely diagnosis?
A. Acute schistosomiasis.
B. Amoebiasis.
C. Leptospirosis.
D. Typhoid.
E. Dengue fever.

25. Answer: D. Typhoid. Clues are Facet sign and onset of symptoms

26. Q
Defects in the terminal attack elements of the complement system (C6, C7, C8) are most strongly associated with an increased risk of infection with which of the following pathogens?
A. Streptococcus pneumoniae.
B. Neisseria meningitidis.
C. Pneumocystis jiroveci.
D. Listeria monocytogenes.
E. Haemophilus influenzae.

27. Answer: B. N. meningitidis
Answer: B. N. meningitidis. Complement is required for bactericidal activity and efficient opsonophagocytosis. Individuals deficient in any of the late complement components (C5-9) cannot assemble MAC needed to kill Neisseria.

28. Q
A 62-year-old man is admitted to hospital with fevers, malaise and myalgias six weeks after a laparoscopic cholecystectomy. On examination he has a temperature of 39°C, splinter haemorrhages and a loud pansystolic murmur. He has a past history of mitral valve prolapse which was diagnosed by echocardiography. Enterococcus faecalis has been identified in three sets of blood cultures. The isolate is highly sensitive to penicillin. He has no known allergies. The most appropriate therapy is:
A. ceftriaxone.
B. vancomycin alone.
C. ampicillin alone.
D. ampicillin and gentamicin.
E. cephalothin and gentamicin.

29. Answer: D. Ampicillin and Gentamicin.

30. Q
A physician becomes ill with nausea and vomiting four hours after attending a pharmaceutical company sponsored dinner. Which of the following is the most likely cause of this?
A. Clostridium difficile.
B. Staphylococcus aureus.
C. Escherichia coli.
D. Vibrio parahemolyticus.
E. Campylobacter jejuni.

31. Answer: B. S. aureus. Clue here is time frame of illness
Answer: B. S. aureus. Clue here is time frame of illness. Preformed toxin mediated = rapid onset.

32. Q
Recurrent infections with which of the following organisms is most characteristic of a disorder of neutrophil phagocytic function (such as chronic granulomatous disease)?
A. Non-tuberculous mycobacteria.
B. Pseudomonas aeruginosa.
C. Nocardia species.
D. Pneumocystis jiroveci (carinii).
E. Staphylococcus aureus.

33. Answer: E. S aureus. Chronic granulomatous disease: group of disorders of granulocyte and monocyte oxidative metabolism. Rare 1:200,000. Often X-linked recessive, or autosomal recessive. Leukocytes have severely diminished hydrogen peroxide production. Leads to increased infection with catalase positive organisms: S. aureus, B. cepacia, Aspergillus spp. Clinical features of excessive inflammation with granulomas, lymph node suppuration, granulomas leading to GI obstruction, gingivitis, aphthous ulcers, seborrheic dermatitis.

34. Q
The emergence of a pandemic strain of influenza is best explained by which of the following mechanisms?
A. Antigenic drift in H and N proteins of influenza A.
B. Antigenic shift in H and N proteins of influenza A.
C. Point mutations in the M proteins of influenza A.
D. Development of neuraminidase resistance.
E. Recombination of influenza A and B haemagglutinins.

35. Answer: B. Antigenic shift.

36. Q
A 42-year-old woman with human immunodeficiency virus (HIV) infection presents to the emergency department with a six week history of general malaise, fever, night sweats and loss of 5kg weight. She was born in Papua New Guinea but came to Australia five years ago. She takes zidovudine, lamivudine and nevirapine. Her viral load is undetectable and CD4 count is 0.41 x 10^9/L [ x 10^9/L]. Examination is unremarkable. Her Chest X-ray shows patchy consolidation in the left upper zone as shown below.

38. What is the most likely cause of the radiological changes?
A. Pneumocystis pneumonia (PCP).
B. Mycobacterium avium complex (MAC).
C. Mycobacterium tuberculosis (MTB).
D. Burkholderia pseudomallei.
E. Cytomegalovirus (CMV).

39. Answer: C. TB. Epidemiology, CXR findings, CD4 count.

40. Q
A 90-year-old female has osteoarthritis and early dementia. She is living at home with her daughter who is her full time carer. Screening tests on her 90th birthday include an mid stream urine (MSU), which showed bacteriuria (mixed growth) and pyuria.
Which of the following strategies is most appropriate?
A. Single dose of amoxycillin.
B. Five day course of trimethoprim.
C. Topical estrogen cream.
D. No intervention.
E. Repeat MSU in three months.

41. Answer: D. No intervention. Asymptomatic bacteriuria
Answer: D. No intervention. Asymptomatic bacteriuria. Multiple guidelines! Surgeons may still need convincing.

42. Q
A 26-year-old man recently returned from an overseas holiday, presents with a two day history of joint pain. On examination his temperature is 38.1 C, he has two small pustular lesions on his left hand, evidence of tenosynovitis of the left 4th flexor tendon and an effusions in the right knee.
Which diagnosis best explains this clinical pattern?
A. Reactive arthritis.
B. Parvovirus infection.
C. Gonococcal arthritis.
D. Staphylococcal arthritis.
E. Sub acute bacterial endocarditis.

43. Answer: C. Gonococcal arthritis
Answer: C. Gonococcal arthritis. Age, arthritis, travel, and no diarrhoea.

44. Q
A 27-year-old medical student presents with three episodes of fevers, headache, chills and rigors and loose stools over the past week. She returned from an elective placement in Papua New Guinea six weeks previously. She took doxycycline for malaria prophylaxis. Examination reveals a fever of 40 C, but no other abnormal findings. Her chest X-ray is clear. The following test results were obtained:
Haemoglobin (Hb) 115 g/L [115 – 135 g/L]
White cell count (WCC) within normal limits
Platelet count 120 x 10^9 /L [150 – 400 x 10^9 /L]
Thick and thin blood films no parasites detected
Liver function tests within normal limits

45. In addition to blood cultures, what is the most appropriate next step?
A. Repeat thick and thin blood film.
B. Dengue polymerase chain reaction (PCR).
C. Mantoux test.
D. Oral metronidazole.
E. Oral ciprofloxacin.

46. Answer: A. Repeat thick and thin films
Answer: A. Repeat thick and thin films. Prolonged incubation and symptom constellation make some diagnoses more likely. Sensitivity of smear will depend on parasitaemia, the operator and the time the smear was taken. Usually get a series of 3. One negative smear does not exclude malaria.

47. Q
A 20-year-old male with known human immunodeficiency virus (HIV) infection is admitted from the community with a two day history of cough and sputum production. On examination he has a temperature of 38 C and his chest X-ray shows patchy opacification of the right middle and lower lobes.
The most likely organism responsible for his clinical features is:
A. Streptococcus pneumoniae.
B. Legionella pneumophila.
C. Mycobacterium avium-complex
D. Pneumocystis jiroveci (carinii).
E. Cytomegalovirus (CMV).

48. Answer: A. Strep pneumo. Common things occur commonly…

49. Q19. Recall question.
Regarding the mechanism of resistance in MRSA, which of the following is correct:
A. MRSA produces an altered Penicillin-binding protein (PBP2) a products of the mecA gene which is carried by the mobile genetic element called SCCmec
B. MRSA produces altered PBP2 a products of the mecA gene which has a very high affinity for beta lactam antibiotics
C. MRSA produces a B-lactamase which is a product of the mecA gene
D. MRSA resistance to B-lactams is via a thickened cell walls
E. MRSA resistance mechanism is via porins

50. Answer: A. MRSA produces an altered PBP2, a products of the mecA gene which is carried by the mobile genetic element called SCCmec. PBP2 has a low affinity for beta lactam antibiotics.

51. Q20. Recall question.
Tuberculosis (TB) is a treatable airborne infectious disease that kills almost 2 million people every year, which is INCORRECT:
A. Multidrug-resistant (MDR) TB is caused by strains of Mycobacterium tuberculosis that are resistant to isoniazid and rifampicin
B. XDR TB is extensively drug resistant TB - resistant to an aminoglycoside and a fluoroquinolone as well as isoniazid and rifampicin
C. 1 in 10 patients with TB in China has MDR TB and 1 in 120 has XDR TB
D. Rates of resistant TB are highest in newly diagnosed patients who have not received any treatment
E. TB is an AIDS defining illness

52. Answer: D. Rates of resistant TB are highest in previously treated patients.

53. Q21. Recall question.
A patient returns from travel from SE Asia – his first travel overseas – with 2 day history of fever (≥38.5°C), accompanied by headache, retro- orbital pain, myalgia, and joint pain, and a transient macular rash. Laboratory findings include moderate thrombocytopenia and leukopenia, and a moderate elevation of hepatic aminotransferase levels. The best (ie likely positive) test for diagnosis on presentation is:
A. Dengue viral nucleic acid PCR or viral non-structural protein 1 (NS1)
B. Specific dengue IgM antibodies
C. Thick and thin smears and malaria antigen test
D. Typhoid serology
E. Blood culture for S typhi

54. Answer: A. Serology likely becomes positive later- 7-10 days after symptom onset.

55. Q22. Recall question.
A surgical unit realized that its S.aureus surgical site infection rate is increasing and would like to implement an intervention to reduce this trend. Which of the following practices is likely to be useful?
A. Extensive shaving of incision site before surgery
B. Eradication of S. aureus carriage prior to surgery with topical decolonization therapy
C. Using air filter in theatre (HEPA-system air filter)
D. Use of alcohol-based hand cleansers
E. Isolation of patients with infections

56. Answer: B.

57. Q23. Recall question.
Cases of NDM-1 in Escherichia coli in Canada and in Klebsiella sp. in Australia have been reported and have involved patients who had recently travelled to India. Which of the following is FALSE
A. NDM-1 may be plasmid mediated
B. Contact precautions and isolation are necessary for patients with this organism
C. NDM E coli are usually only susceptible to vancomycin
D. blaNDM-1 gene produces NDM-1, which is a carbapenemase beta- lactamase
E. NDM-1 enzyme is a class B metallo-beta-lactamase

58. Answer: C. New Delhi metallo-beta-lactamase-1 (NDM-1) is an enzyme that makes bacteria resistant to antibiotics of the carbapenem family, by hydrolysing and inactivating carbapenems. NDM E coli are usually susceptible to polymyxins.

59. Q24. Harrison’s
year-old male with HIV/AIDs is brought to hospital after a generalized tonic-clonic seizure. He is an IVDU and is not taking ART. His last CD4 count was 43. Further history is not available. His vital signs are stable. On examination he is post ictal and cachectic. There is no nuchal rigidity or focal defects. He has normal renal function. An urgent MRI with gadolinium is performed.

61. Which of the following will be the most effective therapy?
Caspofungin
INH, rifampicin, PZA, and ethambutol
Pyramethamine plus sulfadiazine
Streptokinase
Voriconazole

62. Answer: C. Pyrimethamine plus sulfadiazine Toxoplasma gondii
Answer: C. Pyrimethamine plus sulfadiazine Toxoplasma gondii. Cats definitive hosts for sexual phase with oocytes spread in faeces. ~70% of people over age 50 have serologic evidence of exposure. HIV patients at risk with latent reactivation with CD4 count less then 100. CNS encephalitis most common form. Bactrim is a treatment alternative.

63. Q25. Harrison’s
17.
In a patient with bacterial endocarditis, which of the following echocardiographic lesions is most likely to lead to embolization?
5mm mitral valve vegetation
5mm tricuspid valve vegetation
11mm aortic valve vegetation
11mm mitral valve vegetation
11mm tricuspid valve vegetation

64. Answer: D. Mitral valve vegetation of increased size.

65. Q26. Harrison’s
21.
All of the following statements regarding the etiology and epidemiology of osteomyelitis are true EXCEPT:
After a foot puncture, 30-40% of diabetics will develop osteomyelitis
In patients with prosthetic joints, Staphylococcus aureus bacteraemia will cause osteomyelitis in 25-30% of cases
Mycobacterium tuberculosis is an uncommon cause of osteomyelitis
The foremost bacterial cause of bacterial osteomyelitis is Staphylococcus aureus
Morbidity and economic consequences are greater for MRSA osteomyelitis compared to MSSA osteomyelitis

66. Answer: C. Pott’s disease
Answer: C. Pott’s disease. Often have to think globally when answering questions.

67. Q27. Harrison’s
58.
Which of the following organisms is most likely to cause infection of a shunt implanted for the treatment of hydrocephalus?
Bacteroides fragilis
Corynebacterium diphtheriae
Escherichia coli
Staphylococcus aureus
Staphylococcus epidermidis

68. Answer: E. S. epi. Skin organism, “sticky”

69. Q28. Harrison’s
year old woman with frequent hospital admissions related to alcoholism presents to ED after being bitten by her dog. She has open wounds to her arm that are purulent with necrotic borders. She is hypotensive and is admitted to ICU. She is found to have DIC, and soon develops MOF. Which of the following is most likely to have caused her rapid decline?

70. Aeromonas spp.
Capnocytophaga spp.
Eikenella spp.
Haemophilus spp.
Staphylococcus spp.

71. Answer: B. Capnocytophaga spp
Answer: B. Capnocytophaga spp. Associated with dog bites, often serious disease in immunosuppressed. Often Rx pip-taz, clinda.

72. Q29. Harrison’s
161.
A 28 year old male is diagnosed with HIV infection during a clinic visit. He has no symptoms of opportunistic infection. His CD4 count is All of the following are primary prophylactic routines for PCP EXCEPT:
Nebulized pentamindine 300mg monthly
Atovaquone 1500mg po daily
Clindamycin 900mg po q8h, plus primaquine 30mg po daily
Dapsone 100mg po daily
Bactrim SS, 1 tablet po daily

73. Answer: C. Clindamycin and Primaquine. This is a therapeutic routine.

74. Q30. Harrison’s
196.
An HIV positive patient with a CD4 count of 110 who is not taking any medications presents to an urgent care center with complaints of a headache, nausea and intermittent blurred vision, for the past week. He has normal physical examination apart from mild papilledema. Head CT does not show dilated ventricles. The definitive diagnostic test is:
Cerebrospinal fluid culture
MRI with gadolinium
Opthalmologic examination, including visual field testing
Serum cryptococcal antigen
Urine culture

75. Answer: A. CSF culture. MRI and cryptococcal antigen may be suggestive of cryptococcal meningoencephalitis but not definitive. Small false positive rate for antigen testing.