Infectious Diseases Review Course

1. Infectious Diseases Review Course Hail M. Al-Abdely, MD Consultant, Infectious Diseases

2. Human immunodeficiency virus (HIV) infected patients have a greatly increased risk of all of the following cancers EXCEPT • Kaposi Sarcoma • Cervical Cancer • Non-Hodgkin's Lymphoma • Central Nervous System Lymphoma • Malignant Melanoma

3. An outpatient liver transplant recipient suddenly develops fever, chills, and bacteremia 2 months after transplantation. The most likely source of the bacteremia is • Lungs • Urinary tract • Wound infection • Biliary stricture • Sinuses

4. Syphilis in HIV-infected persons is characterized by all of the following except • A strong association between the two infections • A predilection for more florid clinical signs and symptoms • An increased likelihood of treatment failure, especially with benzathine penicillin • Uniform success of treatment with high-dose penicillin or ceftriaxone • A propensity to develop high nontreponemal titers

5. A 47-year old man with HIV infection presents with extensive purplish skin nodules. There are 32 lesions on his arms, chest and legs, all of which have appeared in the past 6 weeks. His CD4 cell count is 70/uL. Punch biopsy of one lesion shows Kaposi’s sarcoma. Which one of the following statements is true? • Lesions appear at a rapid rate only in patients with very advanced HIV disease – those with CD4 cell counts less than 100/uL • This patient is unlikely to respond to interferon alfa regardless of his CD4 cell count • This patient is almost certainly homosexual or bisexual, because Kaposi’s sarcoma rarely occurs in patients in other risk groups • the percent of HIV-infected homosexual men who develop Kaposi’s sarcoma has been reasonably stable since 1982 • Most patients with Kaposi’s sarcoma die due to visceral involvement by the tumor, especially involvement of the lungs and gastrointestinal tract

6. Which of the following is the most accurate statement regarding Toxoplasma gondii encephalitis in persons with HIV infection? • The absence of lesions on computed tomography (CT) of the head obviates the need for further investigation into the possibility of Toxoplasma gondii encephalitis • Generally, brain biopsy should be done in patients with characteristic focal central nervous system lesions with positive Toxoplasma gondii serology in order to rule out the possibility of other treatable causes of focal central nervous system lesions • The most common findings on head CT scan are single ring-enhancing lesion with mass effect • If a patient with the appropriate clinical findings has not improved within 14 days of therapy with empiric pyrimethamine plus sulfadiazine, brain biopsy should be done

7. All of the following statements are true about fluconazole EXCEPT • It is a fungistatic agent • It is inactive against Candida krusei • It is active against isolates of Trichosporon beigelii • It is useful in the long-term management of cryptococcal meningitis • It is the drug of choice for the treatment of disseminated histoplasmosis

8. Fungal infection remains a major source of morbidity and mortality in marrow transplant recipients. Which of the following statements regarding fungal infections is true? • Candida tropicalis is more often found as a colonizer than as the true etiology of infection in transplant recipients. • Aspergillus species may cause pneumonia, sinusitis, or infection of the CNS. • Candida albicans rarely causes true infection in marrow transplant recipients. • Pityrosporum species cause a disseminated skin rash in marrow transplant recipients that usually require systemic antifungal therapy. • Abnormal donor immune function remains the greatest risk for the development of fungal infection.

9. The following regimens are acceptable initial therapy for HIV-patients except: • Zidovudine, stavudine, nelfinavir • Stavudine, lamivudine, indinavir • Stavudine, didonasine, nelfinavir • Zidovudine, nevirapine, nelfinavir • Zidovudine, lamivudine, efavirenz

10. A 19 year-old Saudi female with sickle-cell disease presented to the ER with 2 day history of fever, cough and SOB. O/E was febrile 39C, RR 30 and BP 80/50. Has crackles bilaterally and CXR revealed bilateral lower lobe consolidation. WBC 24000 with 35% band forms, HgB 39 gm/l. The appropriate antibiotic regimen for this patient is: • Penicilin G 3 MU every 4 hours • Ceftriaxone 2gm every 24 hours • Ceftazidime 2gm every 8 hours and gentamicin 2mg/kg every 12 hours • Vancomycin 1gm every 12 hours and Ceftriaxone 2gm every 24 hours • Nafcillin 2gm every 4 hours and ciprofloxacin 400mg i.v every 12 hours

11. A 50 year/old male who had a liver transplant one year ago. He is on tacrolimus  with normal LFT. He presented to the ER with one day history of diffuse vesicular skin rash all over his body. Chest, abdomen and neurological examinations were normal. CXR was normal. What will be your action? • Admit and start intravenous acyclovir 10mg/kg Q8hrs • Admit and start intravenous acyclovir and ceftriaxone • Admit and start intravenous acyclovir and oral predisone • Discharge from ER on valacyclovir (Valtrex) 1gm Q8hrs • Discharge from ER on famciclovir (Famvir) 500mg Q8hrs

12. 20 year-old Saudi male with acute myeloid leukemia who developed E. coli, coagulase negative staph and C. albicans blood streem infections during neutropenia. He was treated with cefepime, gentamicin and amphotericin B for which he has an excellent response. Treatment was continued throughout neutropenia and for three days after recovery of white cells, and was discharged home. One week later the patient presented with fever, rigors and malaise for 2 days. He was admitted, and 2 sets of blood culture were negative and had a negative CXR. WBC 4.5. CT abodomen showed mutliple enhancing lesions in the liver, spleen and R-kidney. The most appropriate theray is. • Piperacillin/tazobactam and gentamicin • Piperacillin/tazobacam, gentamicin and vancomycin • Meropenem and vancomycin • Amphotericin B • Meropenem, vancomycin and amphotericin B

13. All of the following are poor prognostic factors in Cryptococcal meningitis except: • Cerebrospinal fluid (CSF) leukocytosis • Serum of CSF cryptococcal antigen titer >1:32 • Elevated CSF opening pressure • Altered mental status • Low CSF glucose

14. All true about Listeria monocytogenes except: • Is a gram positive motile rod. • Can be treated effectively with trimethoprim/sulfamethoxazole. • Can cause illness in immune competent individuals • The highest risk group to have infection is bone marrow transplant recipients. • Pasteurization kills this organism

15. Which of the following microbes is most likely to cause a cerebrospinal fluid showing elevated protein and a polymorphonuclear pleocytosis in late-stage HIV infection? • Toxoplasma gondii • Cytomegalovirus • Treponema pallidum • JC virus (Progressive multifocal leukoencephalopathy) • Herpes simplex

16. A 52 year old man with 20 years of Type 2 diabetes mellitus undergoes pancreas and renal transplantation. His post-operative course is complicated by severe  sinusitis. Cultures reveal Rizopus spp. Local sinus surgery is performed, and Amphotericin B deoxycholate is administered with shakes, hypokalemia, and deterioration in renal function. The best course of action is: • Continue amphotericin B and reduce cyclosporine levels • Replace amphotericin B with itraconazole • Replace amphotericin B with liposomal formulation of amphotericin B • Replace amphotericin B with fluconazole • Increase fluid intake to reduce nephrotoxicity

17. 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 39.7°. 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 37.8° 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:

18. Determine the neutrophil count, obtain blood cultures including one set through the Hickman line, begin vancomycin, ceftazidime and an aminoglycoside • Determine the neutrophil count, obtain blood cultures including one set through the Hickman line, begin ceftazidime and an aminoglycoside • 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 • 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 • Obtain blood cultures including one through the Hickman line; Determine the neutrophil count, and begin vancomycin only (whether neutropenic or not)

19. For which of the following exposures would the use of HIV PEP be recommended? • A housekeeper sustains a percutaneous injury while emptying a needle box on a pediatric ward with no known cases of HIV infection. • A nurse has a urine splash to the eye while emptying an AIDS patient's urine. • A resident, after assisting with an emergency insertion of a central venous line into an HIV-infected patient, notices a small tear in his/her glove but does not observe any blood on his/her skin. • A phlebotomist sustains a percutaneous injury while performing phlebotomy on an HIV-infected patient with low viral load. • All of the above.

20. A 32-year-old man with advanced HIV infection presents with cough and low grade fever of two weeks duration. He has a history of PCP, thrush, ITP, and wasting. Recent medications include ddI, d4T, nelfinavir, dapsone, nystatin, and prednisone. Chest x-ray shows a cavity lesion measuring 4 cm in the right lower lobe. A BAL yields Candida albicans, Nocardia asteroides, P. aeruginosa, and CMV. Which of the following antibiotics should be given? • Ganciclovir • Trimethoprim-sulfamethoxazole • Amphotericin B • Fluconazole • Ceftazidime

21. A patient with HIV infection, treated with HAART, and a CD4 count of 240/mm3 has the findings shown in the photograph on retinal (funduscopic) exam. The most appropriate therapy is: • Pyrimethamine plus sulfamethoxazole • Intravenous ganciclovir • Intravenous cidofovir • Amphotericin B • No treatment

22. A 30-year-old man with HIV infection with a CD4 count of 680/mm3 is referred for evaluation of refractory sinusitis. He reports headaches, purulent nasal drainage and nasal stuffiness for 2 weeks. There has been no documented fever. Prior treatment consisted of amoxicillin x 5 days, then TMP-SMX, one DS bid x 3 days; epinephrine nasal spray and ibuprofen has been given for 2 to 3 weeks. Diagnostic studies included the following: CT scan--bilateral air fluid levels in maxillary sinuses Nasal drainage--PMNs and eosinophils Culture--moderate S. aureus sensitive to methicillin WBC--7,800 with 62% PMNs, 4% bands, 20% lymphocytes, 9% monocytes, 5% eosinophils. The treatment that is likely to be most effective is: • Dicloxacillin • Decongestant nasal spray • Cortisone nasal spray • Ipratropium bromide nasal spray • Cough syrup containing dextromethorphan

23. A pregnant woman has a CD4 count of 550/mm3 and viral load of 860 c/ml with no antiretroviral therapy. Which of the following has demonstrated benefit in preventing perinatal transmission in this setting? • AZT monotherapy • Nevirapine • HAART • C-section • None of the above The frequency of HIV perinatal transmission is low when the viral load is <1,000 c/ml, but a review of seven prospective studies of perinatal transmission in the U.S. and Europe showed that there was a significant reduction even further when AZT was given (JID 2001;183:539).

24. A 30-year-old woman presents with watery diarrhea with 6-8 stools/day for nearly 2 months. She is discovered to have HIV infection with a CD4 count of 22/mm3. A stool AFB smear is shown. Which of the following treatments is most likely to eradicate the pathogen? • Paromomycin • Trimethoprim-sulfamethoxazole • Albendazole • Nitrazoxanide • Highly active antiretroviral therapy (HAART

25. A lymph node biopsy from an HIV-positive patient currently residing in the state prison is submitted to the laboratory for acid-fast smear and culture. The acid-fast smear is reported as positive. Acid-fast organisms are recovered on solid medium after 3 days of incubation. This organism is likely to be: • Mycobacterium xenopi • Mycobacterium kansasii • Mycobacterium fortuitum. • Mycobacterium tuberculosis • Mycobacterium avium

26. A 32-year-old drug user is seen in an emergency department with abdominal pain and fever. He has known HIV infection and a recent CD4 count was 10/mm3. He reports that he has had intermittent diarrhea with 2 to 6 loose stools daily for about 2 weeks, and then noted nausea, vomiting, and right upper quadrant abdominal pain. Physical exam shows a temperature of 38.5 C and right upper quadrant tenderness. Medications include AZT, ddI, TMP- SMX, fluconazole, acyclovir, and megavitamins. Laboratory tests show the following: Hematocrit: 29% WBC: 3200 (72% PMNs, 8% bands, 10% lymphs, 5% monocytes, and 5% eosinophils) Platelet count: 88,000/mm3 Bilirubin: 1.4 mg/dL, AST: 121 U/L, ALT: 135 U/L Alkaline phosphatase: 860 U/L Chest x-ray: Negative Abdominal flat plate: Negative Ultrasound of abdomen: Dilated biliary ducts without stones Stool ova and parasite exam with AFB stain: Negative The most likely cause is:

27. An adverse drug reaction • Cryptosporidia • Cyclospora • Entamoeba histolytica • Mycobacterium avium

28. The diagnosis of progressive multifocal leukoencephalopathy is supported by which of the following findings? • Cerebrospinal fluid pleocytosis • Cerebrospinal fluid elevated protein • Fever • Rapid onset of symptoms • Brain biopsy with positive stain for SV-40 virus

29. Which of the following drugs is least likely to cause lactic acidosis? • AZT • 3TC • ddC • ddI • Tenofovir

30. A 30-year-old man has been treated with AZT, 3TC, ritonavir, and indinavir for three years. His CD4 count increased from 230 to 550/mm3 with VL<50 c/ml for over two years. He decides to stop therapy. When should HIV become detectable? • One week • Two weeks • Four weeks • Eight weeks • Three months

31. Which of the following decreases blood levels of indinavir? • Delavirdine • Efavirenz • Nelfinavir • d4T • Ketoconazole Efavirenz decreases the AUC of indinavir by 31%. The practical application is that the dose of indinavir when these two drugs are used together should be increased to 1,000 mg q8h. All of the other drugs that are listed increase the levels of indinavir.

32. Which of the following drugs is most likely to increase the fasting blood glucose? • Tenofovir • Hydroxyurea • Nevirapine • Indinavir • IL-2 There is some substantial confusion about the agents and mechanisms of lipodystrophy, but this is not the case with insulin resistance resulting in elevated blood sugar. All protease inhibitors are associated with insulin resistance, which can be measured within days of administration. Thus, indinavir is the best option since this is the only PI on the list.

33. Food should be given with: • Amprenavir • Indinavir • AZT • Nevirapine • Lopinavir

34. A 37-year-old man with AIDS is receiving AZT, ddI and nelfinavir. He has done well with a viral burden that decreased from 88,000 copies/dL to undetectable. At his last clinic visit he is noted to have a CBC showing an absolute neutrophil count of 400/mm3; neutropenia is confirmed. A review of prior CBCs shows all had ANC values >1800/mm3. The preferred regimen for this patient among the options given is: • ddI, d4T, and saquinavir (Fortovase) • d4T, ddI and nelfinavir • 3TC, ddI and indinavir • ddC, ddI and ritonavir • ddI, ritonavir and saquinavir

35. A 40-year-old man with HIV infection and a CD4 count of 360/mm3 is taking INH due to a positive PPD skin test. After one month of treatment the ALT increased from 30 IU/dL at baseline to 90 IU/dL. The upper limit of normal is 35 IU/dL. The patient is asymptomatic. What treatment should be given? • Continue INH in same dose • Discontinue prophylaxis • Substitute rifampin • Substitute rifampin + ethambutol • Biopsy the liver and then continue INH if there is no evidence of drug-induced hepatitis The current recommendations with INH and hepatic function testing is that increases of 3 - 5-fold for transaminase levels should lead to careful monitoring, but discontinuation of INH is not necessary unless the increase is 5 - 10-fold higher of the upper limits of normal.

36. For the average patient, which of the following treatments gives the longest delay in relapse of CMV retinitis? • IV ganciclovir • IV foscarnet • IV cidofovir • Ganciclovir implant • Oral ganciclovir The median times to progression with initial with CMV retinitis are: ganciclovir IV of 47 - 104 days, foscarnet IV 53 - 93 days, ganciclovir plus foscarnet IV 129 days, oral ganciclovir 29 - 53 days, cidofovir IV 64 - 120 days, ganciclovir implant (Vitrasert) 216 - 226 days.

37. Most patients in late-stage HIV infection develop toxoplasmosis from which of the following? • New infection following exposure to cat stool • New infection following exposure to undercooked meat • New infection from exposure to a patient with toxoplasmosis • New infection from contaminated water • Activation of latent infection

38. The risk of which of the following HIV-associated complications is the least reduced by immune reconstitution with HAART? • Kaposis sarcoma • HIV-associated dementia • Non-Hodgkins lymphoma • Thrush • Pneumococal pneumonia

39. A patient sees you complaining of a sore mouth for 2 days. There is a history of genital herpes, pneumococcal pneumonia,zoster, oral hairy leukoplakia and a positive PPD. The CD4 count is 205/mm3 and current medications include nevirapine, nelfinavir, ddI, hydroxyurea, trimethoprim-sulfamethoxazole, and sertraline (Zoloft). Oral exam is shown in the figure. A Tzanck prep of the lesion is negative. Which of the following is most likely to provide relief? • Acyclovir therapy • Thalidomide therapy • Discontinue nevirapine • Discontinue trimethoprim sulfamethoxazole • Discontinue nelfinavir

40. Human herpes virus 8 has been most convincingly implicated in which of the following: • Hepatocellular carcinoma • CNS lymphoma • Castleman's disease • Acute myelocytic leukemia • Hypernephroma

41. Which of the following drugs shows the best penetration across the blood-brain barrier? • Zidovudine (AZT). • Stavudine (d4T) • Lamivudine (3TC) • Didanosine (ddI) • Zalcitabine (ddC) With the exception of abacavir, AZT shows the best penetration of the NRTIs across the blood-brain barrier with CSF levels that are approximately 60% of serum levels (Lancet 1998; 351: 1547).

42. A 25-year-old HIV-infected man presents to your office with severe herpes proctitis. The patient has been treated with acyclovir, 200 mg five times daily for six weeks without improvement in the lesions. On repeat culture of the rectum, herpes simplex virus 2 is again isolated and further testing reveals that this is a thymidine kinase-deficient strain. Which is the preferred treatment option for this condition? • Foscarnet • Vidarabine • Ganciclovir • Valacyclovir • Famciclovir

43. A 43-year-old man with AIDS presents with a four-week history of ataxia, progressive right hand weakness, and tremor. Physical examination confirms his symptoms. His CD4 cell count is 56/mm3, and serum antitoxoplasma IgG antibody titer was negative one year ago. An MRI of the head reveals a solitary 2 x 4 cm lesion in the left cerebellar hemisphere which gives a high signal intensity on T2-weighted images but does not enhance with gadolinium. No mass effect is demonstrated. The most likely diagnosis is: • Toxoplasmosis • A fungal abscess • Primary CNS lymphoma • Progressive multifocal leukoencephalopathy (PML) • A mycobacterial abscess

44. Which of the following best predicts long-term HIV suppression? • The nadir of plasma HIV RNA levels following treatment • Treatment in relatively early stage disease as indicated by a CD4 count >200/mm3 • A relatively low plasma HIV RNA level at the time antiretroviral therapy is initiated • Absence of an AIDS-defining opportunistic infection • Use of a regimen that contains 2 protease inhibitors

45. Which of the following is least likely to cause peripheral neuropathy? • Lamivudine (3TC) • Stavudine (d4T) • Didanosine (ddI) • Zalcitabine (ddC) • Zidovdine (AZT)

46. Which of the following statements is correct about cryptococcosis in patients with AIDS. • 70 percent of patients present with respiratory symptoms • Sequestered infection within the prostate is implicated as the cause of relapse in men • Photophobia and neck stiffness occur in the majority of patients with cryptococcal meningitis • A neurotoxin elaborated by cryptococcus is responsible for the neurological symptoms of cryptococcosis • The onset of disease is rapid

47. Which of the following statements is correct about cryptococcosis in patients with AIDS. • 70 percent of patients present with respiratory symptoms • Sequestered infection within the prostate is implicated as the cause of relapse in men • Photophobia and neck stiffness occur in the majority of patients with cryptococcal meningitis • A neurotoxin elaborated by cryptococcus is responsible for the neurological symptoms of cryptococcosis • The onset of disease is rapid