The document summarizes several infectious disease cases presented at a noon conference. The first case discusses a male presenting with cough and fever who was diagnosed with blastomycosis after cytology found Blastomyces dermatitidis. The second case involves a pregnant woman from Nigeria with malaria diagnosed on peripheral smear after visiting a rural village. The third case is about a man returning from Saint Martin with joint pains and fever, possibly due to arboviral infections like chikungunya or dengue. The last two cases discuss a man with L4-L5 osteomyelitis and sacroiliitis diagnosed with brucellosis, and a woman with cervical lymphadenopathy possibly having toxoplasmosis

1. Organism potpourri
Noon Conference 5/6/19
Shingo Chihara, MD

2. Case 1
• 18 year old male who lives in Chicago presenting to the ER with low
grade fever, SOB, and coughing x 3 months. Initially, treated with
azithromycin but symptoms persisted. Chest x-ray taken at the time
showed right lower lobe infiltrate and given levofloxacin. He
presented to the ER since he continued to worsen on levofloxacin.

3. Cytology

4. Blastomycosis
• Blastomyces dermatitidis
• Exposure to soil
• Lung involvement in 90%; Skin in 18%; Bone in 4%
• Cough, Fever, Chest pain, SOB, Weight loss, Night sweats
• Culture for diagnosis
• Urine blastomyces antigen available but not specific and cross-react
with urine histoplasma antigen
• Itraconazole/amphotericin B x 6-12 months

5. Blastomycosis
Endemic in gray
Highest in green
Mandell: Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases, 7th ed.

6. Blastomyces dermatitidis
Broad-based budding yeast
Mason: Murray and Nadel's Textbook of
Respiratory Medicine, 5th ed.
Yeast Phase Mold Phase
Lollipop-like appearance: round conidia
at apex of condiophore

7. Endemic mycosis
• Histoplasma capsulatum
• Blastomyces dermatitides
• Coccidioides immitis/posadasii
• Dimorphic (yeast and mold)
• Infection via inhalation

8. http://www.doctorfungus.org/mycoses/images/North_Amer_Histo.gif

9. Coccidioides immitis and Coccidioides
posadasii
Mandell: Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases, 7th ed.

10. Coccidioides immitis and Coccidioides
posadasii
McPherson: Henry's Clinical Diagnosis and Management by Laboratory Methods, 22nd ed.
Spherules with endospores Alternating barrel-shaped
arthroconidia

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© 2005 Elsevier
Geographic regional distribution of endemic mycoses

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© 2005 Elsevier
Histoplasma: short, cylindrical projections
Blastomyces: broad-based budding
Paracoccidioides: ship’s wheel appearance
Coccidioides: spherule, barrel-shaped
arthroconidia
Penicillium: transverse septa

13. Case 2
25 year old pregnant woman who presented to the ER with fever,
nausea, vomiting x 2 days. She is originally from Nigeria and went back
to visit her family last week in a rural village.

14. Peripheral smear

16. Malaria
• Eliminated from the US in early 1950s
• 1500-2000 cases every year in recent travelers
• VFRs at risk
• Anopheles mosquito
• Transfusion (97 cases from 1963-2012)
• Plasmodium
• P. falciparum: most virulent
• P. vivax and P. ovale with dormant liver stages (hypnozoite); could reactivate
after 2-4 years

17. Global distribution of malaria
P. falciparum
P. vivax

19. Malaria
• Uncomplicated: Non-specific findings: tachycardia, tachypnea, chills,
fatigue, malaise, headache, cough, nausea, vomiting, etc.
• Mild anemia and thrombocytopenia
• Complicated: 5-10% parasitemia
• Altered mental status
• Respiratory distress
• Circulatory collapse
• Metabolic acidosis
• Renal failure
• Liver failure
• Coagulopathy
• Severe anemia
• Hypoglycemia

20. Prevention
• Bednets
• Long sleeves
• DEET/permethrin
• Antimalaria prophylaxis
• Chloroquine
• Doxycycline
• Malarone
• Mefloquine

21. Case 3
• 30 year old male who traveled to Saint Martin for vacation. He
returned last night and presents to your clinic with fever, severe joint
pains and malaise for 2 days.

22. Common infections in return travelers
(incubation period <2 weeks)
• Chikungunya
• Dengue
• Zika
• Arboviral encephalitis (Japanese encephalitis, tickborne encephalitis, West Nile virus)
• Enteric fever
• Acute HIV
• Influenza
• Legionellosis
• Leptospirosis
• Malaria
• Rickettsial disease

23. Chikungunya
• Aedes spp mosquito borne illness
• Reemerged since 2004 mostly in and around Indian Ocean, but cases
in Caribbean/Central America as well
• Joint pains are severe and affect mostly hands/feet symmetrically
• Maculopapular rash on trunk/extremities may be seen
• Diagnosis with serology

24. Dengue
• Occurs in > 100 countries including Puerto Rico, US Virgin Islands
• Nonspecific acute febrile illness
• Classic symptoms: fever, retroorbital pain, muscle pain (break-bone
fever)
• Up to 5% may develop severe dengue
• Persistent vomiting, severe abdominal pain, mucosal bleeding, dyspnea
• Rapid decline in platelets and rise in hematocrit

25. Dengue
• Transmitted by Aedes mosquitoes
• Incubation period of 4-6 days

26. MKSAP questions

29. Conjunctival suffusion
https://openi.nlm.nih.gov/detailedresult?img=PMC3269263_tropmed-86-187-g003&req=4

31. Case 4
• 50 year old Mexican male with chronic back pain who was found to
have L4-L5 osteomyelitis and underwent debridement. There was
evidence of sacroiliitis on MRI as well. Culture was taken, but no
growth was observed. He was discharged on vancomycin and
ceftriaxone. Few days after discharge, the diagnosis was made by
serology.

32. Brucellosis
• Zoonosis transmitted by contact with fluids from infected animals
(sheep, cattle, goats, pigs, etc.) or food products such as
unpasteurized milk/cheese.
• Non specific symptoms
• Osteoarticular involvement most common
• Could infect any organ similar to tuberculosis
• Cause of FUO
• Blood culture: typically would not grow with routine blood culture:
blind subculture or draw in fungal blood culture
• Doxycycline/streptomycin or doxycycline/rifampin

33. Case 5
• 40 year old female who presented to the clinic with bilateral cervical
lymphadenopathy for 2 weeks. Has temperature of 100 but
otherwise feels OK. She has a cat at home but denies being bitten or
scratched.

34. Toxoplasma
• Protozoa
• Transmission
• Ingestion of infectious oocysts from the environment
• Ingestion of tissue cysts in meat from an infected animal or from
contaminated fruits, vegetables or water
• Vertical transmission
• Blood transfusion or organ transplantation
• Seroprevalence of 11% in the US
• Leading cause of blindness in South America

35. Toxoplasma life cycle

36. Organism Potpourri
• Endemic mycosis
• Malaria
• Dengue
• Chikungunya
• Brucella
• Toxoplasmosis

37. Sporothrix schenckii
• Ubiquitous in soil and decaying vegetation
• Nodular and ulcerative lesions along lymphatics
Long: Principles and Practice of Pediatric Infectious Diseases, 4th ed.

38. Penicillium marneffei
• Endemic in Southeast Asia
• Disseminated disease in AIDS

39. Paracoccidioides brasiliensis
Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases, 7th ed.
•“South American blastomycosis”
• Endemic in Latin America
•Brazil, Colombia, Venezuela
•80% with lung involvement
•Slow growing
“Pilots wheel” morphology