Blastomycosis

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Blastomycosis
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History

• 43 male smoker 25 pack seen at OPD
• Unresolving respiratory symptoms for 6/12
• Chronic cough with green sputum
• ? now repeated minimal hemoptysis
• Fever with night sweating intermittent
• Wt loss 45 lbs
• SOBE mild effort

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History

• No orthopnea , PND or CP
• No leg pain or swelling
• NO CTD symptoms
• No contact ,travel
• Works in courier service
• No pets
• PMH PSH FH -ve

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History

• Trial of Abx 2 courses
• Amoxil 2 weeks Gatifluxacine 3 months
• ?no improvement
• Off work being symptomatic
• Referred ? Malignancy

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Examination

• Afebrile RR 16 Sat 96 RA
• BP 130/70 HR 80
• No clubbing
• Chest minimal crackles Lt lower 1/3
• CVS N
• ABD LL N
• No CTD signs

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Investigations

• CBC Coagulation N
• BUN , Creat , lytes N
• LFT N
• UA N
• CXR ?Airspace disease lingula LLL
• ?Lt hilar enlargement
• CT Chest

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Investigations

• Bronchoscopy ?N
• BAL cytology ? -ve for malignancy
• Initial culture ?strept H.Inf
• 3 weeks after Bronch ? new growth

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Blastomycosis
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Blastomycosis

• Blastomyces dermatitidis is a dimorphic fungus
• ?mycelial form at room temperature
• yeast form at body temperature.
  
• Etiology of spectrum of diseases that occur
  either in sporadic or epidemic cases.
• 2 serotypes A antigen ve or ve mainly in
  Africa

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Epidemiology

• Estimating incidence has been difficult
• ? lack of sensitive specific diagnostic
  tests
• considerable number of cases are
  subclinical
• Based on clinical reports of cases endemic areas
  are
• states bordering Mississippi Ohio
  rivers
• ? Southeastern South-central
• states bordering the great lakes
• ? Canadian provinces , Midwestern

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Epidemiology

• Environment is soil containing decayed
  vegetations or decomposed woods
• Rain fall or proximity to water source
  maintaining humidity is a major factor
• Those environmental factors are short lived

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Presentations

• Infection through inhalation of conidia from the
  ruptured mycelia .
• Conidia then rapidly converts to yeast form which
  more resistant to phagocytosis .
• Host defense is cellular
• ? doesn't confer immunity or fasten recovery.

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Presentations

• General fever , malaise ,fatigue Wt loss
• Pulmonary Acute resemble CAP
• Chronic might be mistaken for malignancy
• Reported cases ? empyema ARDS
• CXR ? alveolar disease
• upper lobes predominance
• or Mass , miliary reticulonodular
  pattern
• Cavitations effusions are rare

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Presentations

• Cutaneous 2nd most common
• Isolated or concomitant with respiratory
  involvement
• Either verrucous or ulcerative lesions
• Aspirations or Bx will yield Dx
• Osseous both axial peripheral bones
• radiological findings are non
  specific
• Bx ? granulomatous inflammation

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Presentations

• CNS Meningitis , abscess
• Ventricular fluid has a higher yield than LP
• GU Prostatitis epididmoorchitis
• Rare LN , Liver spleen abscess
• ocular ,adrenal , breast
• Presenting with ITP , Immune hemolysis
• Associated with TB , Histo Coccidio

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Presentations

• Retrospective study In Manitoba
• Jan 1988 ? Dec 1999
• Dx ? clinically either pneumonia or skin lesions
• isolation of fungus by culture or
  cytology
• 143 patients 58.7 Manitoba resident
• 41.3 Ontario resident
• Mean Age 38/- 20 MF 65 Vs 35
• 
  CID May 2002

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Presentations

• 68 Manitoba residents have a ve travel history
  of which 41 to Northwestern Ontario
• Outdoor occupation 13.5
• (occupation was available 138/143 patients )
• Annual incidence 0.62 per 100,000 Manitoba
• 7.1 per 100,000
  Kenora ON

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Presentations

• Manitoba incidence is half the incidence in
  endemic area Wisconsin Mississippi
• Kenora incidence 4 times other Manitoba or ON
  divisions .
• Mortality rate 6.3 mainly respiratory failure
• Mortality was higher in patients with shorter
  symptoms before diagnosis

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Diagnosis

• Blastomyces is not a normal flora
• ?either seeing or culturing it is reliable for
  Dx
• Serology is not helpful because of cross
  reactivity with other fungi
• ?epidemiological assessment
• Skin testing ?high false ve results

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Diagnosis

• Retrospective study 119 patients
• 47 pulmonary involvement
• Inclusion
• 1) Isolation from respiratory samples
• 2) Isolation from non respiratory sample
• clinical radiological picture of
  pneumonia
• 3) Clinical Radiological suspicion
• ve serology
• 
  Chest Mar 2002

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Diagnosis

• High diagnostic yields from culture specimen
• culturing different sources will increase yield
• Increase number of specimens increase yield
• Average time to confirm Dxby Culture
• ? 5 weeks

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Diagnosis

• KOH may provide faster comparable yield to
  cultures
• Serology yield 16-40
• Wet smear cytology might be helpful in
• endemic areas
• when starting treatment is urgent
• to avoid more invasive investigations

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Treatment

• Spontaneous resolution is very uncommon
• Untreated cases might have mortality 60
• No randomized trial comparing antifungal Rx
• Rx selection depends on immune status
• severity of infection
• 
  Infectious dis clin 2003

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Treatment

• Immunocompromized with CNS ,Respiratory failure
  or multioragn failure ?Ampho B
• Itraconazole is the drug of choice 200 mg .
• 6 months cure rate gt 90
• Ketoconazole variable cure rates
• with higher CNS relapse