1. A 55 year old man underwent his third cycle of chemotherapy for Non-Hodgkin's Lymphoma 10 days prior to presentation. He presents with erythema and pain at the Hickman Catheter entry site in his skin and a fever of 101.7° (tympanic). He was well for one week after the chemotherapy infusion, which he tolerated well. However, over the last several days he developed increasing fatigue and had a fever to 99.8° 24 hours ago. He took two acetaminophen and felt better. He developed a rigor this morning, and presents now. Physical exam reveals an erythematous, tender Hickman entry site without surrounding crepitus. The lungs are clear, there are no other skin lesions, and the perianal area is normal without obvious fissures. The next step is [1]:

   
   A. Determine the neutrophil count, obtain blood cultures including one set through the Hickman line, begin vancomycin, ceftazidime and an aminoglycoside
   B. Determine the neutrophil count, obtain blood cultures including one set through the Hickman line, begin ceftazidime and an aminoglycoside
   C. Obtain blood cultures including one through the Hickman line; Determine the neutrophil count; if the patient is neutropenic, begin vancomycin and ceftazidime; if the patient is not neutropenic, begin vancomycin alone
   D. Obtain blood cultures including one through the Hickman line; Determine the neutrophil count; if the patient is neutropenic, begin vancomycin and ceftazidime and an aminoglycoside; if the patient is not neutropenic, begin vancomycin alone
   E. Obtain blood cultures including one through the Hickman line; Determine the neutrophil count, and begin vancomycin only (whether neutropenic or not)

   
   

2. The majority of cephalosporins cover all of the following organisms EXCEPT [2]:

   
   A. Streptococcus pneumoniae
   B. Streptococcus faecium (enterococcus)
   C. Staphylococcus aureus, methicillin sensitive
   D. Escherischia coli
   E. Streptococcus pyogenes

   
   

3. A 28 year man with a history of drug abuse and HIV infection is brought to the emergency room with loss of consciousness. He was diagnosed with AIDS 6 months ago with candidial esophagitis and a CD4 count of 186/µL. He began zidovudine (AZT) at that time and continues to take it. His CD4 count two weeks ago was 80/µL. He has had declining mental status over the past week and developed fevers 2 days ago, worse at night. He takes aerosolized pentamidine monthly for pneumocystis prophylaxis and uses fluconazole intermittantly for recurrent oral and esophageal thrush. He is allergic TMP/SMX (Bactrim®), developing a severe diffuse erythematous rash and difficulty breathing. He is arousable to moderate pain on exam, and his pulse is 110 per minute, respiratory rate 16 per minute, blood pressure 115/75mmHg, and temperature 101°F orally. His examination is notable for mild bilateral papilledema, no meningismus, no icterus, mild oral thrush, and 4/5 weakness in the left ankle on plantar flexion and a left upgoing toe (positive Babinski sign). A CT scan of the head reveals several ring enhancing lesions.The most likely diagnoses are [3]:
   

   
   A. CNS Lymphoma > Progressive Multifocal Leukoencephalopathy
   B. Toxoplasmosis > Progressive Multifocal Leukoencephalopathy
   C. Progressive Multifocal Leukoencephalopathy > Fungal Abscess
   D. Progressive Multifocal Leukoencephalopathy > CNS Lymphoma
   E. Toxoplasmosis > CNS Lymphoma

   
   

4. A lumbar puncture does not limit the differential diagnosis, and empiric therapy is begun. The patient is treated for 10 days, with initial improvement in mental status. However, his condition worsens over the next several days. A repeat CT scan shows 25% increase in size of two of the lesions. Signs of herniation are not present. The most appropriate next step is [4]:

   
   A. Repeat Lumbar Puncture and Brain Biopsy
   B. Repeat Lumbar Puncture, Special CNS Cultures, and empiric antifungal therapy
   C. Anti-herpesviral therapy following Repeat Lumbar Puncture
   D. Repeat Lumbar Puncture, High Dose Dexamethasone
   E. Repeat Lumbar Puncture, MRI Scan of the Brain, Empiric Antibacterial Therapy

   
   

5. The patient's condition is diagnosed, treatment instituted, and he improves. Anti-retroviral therapy at this time should MOST LIKELY be changed to [5]:

   
   A. Triple therapy including an HIV-protease inhibitor
   B. Addition of limovudine to the zidovudine
   C. Stop zidovudine and start Didanosine (DDI) + Limovudine
   D. Stop zidovudine and start Didanosine alone
   E. Stop zidovudine and use an HIV- protease inhibitor alone

   
   

6. The patient should also be started on Mycobacterium avium complex (MAC) prophylaxis. Which of the following is probably the BEST prophylaxis for MAC [6] ?
   

   
   A. Rifampin
   B. Rifabutin
   C. Rifabutin + Clarithromycin (or Azithromycin)
   D. Clarithromycin or Azithromycin alone
   E. Ethambutol + Ciprofloxacin

   
   

7. The following are true of Group B Streptococcus EXCEPT [7]:

   
   A. Major cause of sepsis and meningitis in newborn infants in USA
   B. Major cause of Pregnancy-related morbidity and mortality
   C. Incidence has been decreasing in non-pregnant adults in the USA
   D. Nearly all isolates are sensitive to penicillin
   E. Risk Factors include Age >60 years, diabetes mellitus, malignancy, and HIV

   
   

8. All of the following are true about extended range penicillins EXCEPT [8]:

   
   A. Addition of sulbactam to ampicillin improves anti-staphylococcal coverage
   B. Addition of tazobactam to piperacillin (Zosyn®) improves anti-pseudomonal coverage
   C. Mezocillin and ticarcillin have similar Gram negative rod coverage
   D. Ticarcillin-clavulonate is reasonable empiric coverage for infected diabetic foot ulcers
   E. Amoxicillin-clavulonate is reasonable for treatment of recurrent sinusitis

   
   

9. All of the following are true about Giardia infection EXCEPT [9]:

   
   A. Causes abdominal pain and increased flatulance in most persons
   B. May be treated with metronidazole or quinacrine
   C. Can cause malabsorption with chronic diarrhea
   D. Often picked up from contaminated water
   E. Usually causes a bloody, watery diarrhea

   
   

10. All of the following are true about itraconazole EXCEPT [10]:

    
    A. It is taken orally
    B. It has activity against histoplasma and coccidiomycosis
    C. It crosses the blood-brain barrier
    D. It has some activity against aspirillis
    E. It deposits in nail beds with good activity against onychomycosis

    
    

Answers

1. D (Double gram negative coverage is still recommended in patients with fever and neutropenia).
2. B
3. E
4. A
5. A
6. D (Best safety to efficacy profile of all regimens known to date.)
7. C
8. B
9. E (Usually non-bloody diarrhea.)
10. C