Opportunistic Mycoses (Lecture)

Question 1

HIV positive patient presents with 3 months of nonproductive cough, progressive DOE, and substernal tightness. A chest x-ray reveals diffuse interstitial infiltrates. He does not improve despite receiving a round of azithromycin and ceftriaxone. His sputum is silver stain positive. What is the most likely causative agent, diagnosis and treatment? What would be the treatment if he were unconscious (unable to take anything PO)?

Answer 1

Pneumocystis jiroveci is the most likely cause and is and AID defining illness. His CD count is likely below 200
Trimethoprim / sulfamethoxazole is appropriate if PO tolerant, if not pentamidine IV

Question 2

Patient who was recently started on regimen for PCP returns to your office with worse pneumonia symptoms and is concerned. He would like to change his medication because he does not think it is working. CXR does not show any change is the disease course. What should be your course of action?

Answer 2

Continue current treatment. It is common for the patient to get worse before getting better.

Question 3

What marker is used to determine prophylactic treatment of PCP and what is the DoC?

Answer 3

CD 4 less than 200

Trimethorpim / sulfa

Question 4

Patient with a history of HIV and CD 4 counts greater than 400 who has not been seen in years shows up with extreme headaches and reports having a cat at home. CT shows multiple ring enhancing lesions in her brain. What is the likely causative agent and diagnosis?

Answer 4

Toxoplasmosis

AIDS, this pt. likely has a CD 4 count below 100

Question 5

What is the first line tx for toxo?

Answer 5

Pyrimethamine / sulfadiazine

Question 6

What is first line prophylaxis of toxo?

Answer 6

Trimethoprim / sulfa

Question 7

Patient with a history of poorly controlled HIV reports seeing flashes of lights in her peripheral vision. On optho exam, you see yellow-white granular areas, perivascular exudates and hemorrhages. What is the likely causative organism, diagnosis, and first line oral treatment?

Answer 7

CMV
AIDS with CD 4 less than 50
Valganciclovir is most commonly used oral agent

Question 8

24 y.o. prostitute who was recently treated for a yeast infection presents with a white plaque on her tongue and in her esophagus. You are able to scrape a sample off, but cause a small amount of bleeding in doing so. Microscopy reveals yeast, pseudohyphae and germ tubes. What is the most likely causative agent and diagnosis?

Answer 8

Candida produces hyphae, pseudohyphae, yeast and germ tubes

Trush in the esophagus is an AID defining illness

Question 9

What are the two most commonly used medications for candida?

Answer 9

Azoles (esp fluconazole)

Amphotericin B

Question 10

Patient with a history of poorly controlled HIV presents with meningitis. He has a bird at home. Microscopy with India ink of the fluid gathered during an LP reveals broad budding yeast that have large capsules. What is the most likely causative agent and treatment?

Answer 10

Crytpococcus
Treat severe infection with amphotercin B
Mild disease is treated with fluconazole

Question 11

What is the most common opportunistic infection in AIDS?

Answer 11

PCP

Question 12

Patient with a history of AIDS presents with sub acute pneumonia and neutropenia. Culture shows parallel contours and acute angle branching. What is the causative organism?

Answer 12

Aspergillus

Question 13

What is the growth pattern of Mucormycosis?

Answer 13

Non-septate with obtuse branching hyphae