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Aspergillosis and Systemic mycoses R Lin NP/09
Fungal infections <ul><li>Most fungal infections are opportunistic – candida is the most common causing skin and soft tiss...
Aspergillosis <ul><li>Found in the air all around us </li></ul><ul><li>Harmless to normal people </li></ul><ul><li>Opportu...
Spectrum of disease <ul><li>Colonization : sinuses, lungs </li></ul><ul><li>Toxicosis :  aflatoxin ( A. flavus ) </li></ul...
Invasive aspergillosis <ul><li>Most commonly in severely neutropenic e.g. after bone marrow transplant </li></ul><ul><li>P...
Laboratory investigation <ul><li>Microscopy: KOH prep, sputum, bronchoalveolar lavage </li></ul><ul><li>Histology : lung <...
Galactomannan EIA <ul><li>Monitor post-transplant  patient 2x / week </li></ul><ul><li>Rising value or high value + sympto...
 
 
 
 
 
 
TRUE SYSTEMIC (ENDEMIC) MYCOSES <ul><li>Coccidioidomycosis </li></ul><ul><li>Histoplasmosis </li></ul><ul><li>Blastomycosi...
TRUE SYSTEMIC MYCOSES General features <ul><li>Causative agents:  thermally dimorphic  fungi that exist in nature, soil </...
Endemic mycoses <ul><li>Geographical location;  h/o travel ; except histoplasmosis (worldwide) </li></ul><ul><li>Clinical ...
Tests for systemic mycoses <ul><li>Microscopy </li></ul><ul><li>Fungal culture (2 temperatures!) </li></ul><ul><li>Tissue:...
COCCIDIOIDOMYCOSIS <ul><li>Aetiology :   Coccidioides immitis </li></ul><ul><li>Location :  Confined to southwestern US, n...
Case history A 71-year-old male subject regularly spends several winter months in Arizona to play golf in the sun. Last Ma...
Other presentations Months to years following a symptomatic or asymptomatic infection, the affected lung may show complete...
Coccidioides immitis
Coccidioides immitis
Disseminated coccidioidomycosis
Histoplasma capsulatum
HISTOPLASMOSIS <ul><li>Aetiology:   Histoplasma capsulatum </li></ul><ul><li>Natural reservoir:   soil, bat and avian habi...
Histoplasma capsulatum
Histoplasma
 
 
 
Blastomyces dermatitidis
BLASTOMYCOSIS <ul><li>Aetiology :   Blastomyces dermatitidis  </li></ul><ul><li>Location :   America, Africa, Asia </li></...
Blastomycosis
Paracoccidioides brasiliensis
PARACOCCIDIOIDOMYCOSIS <ul><li>Aetiology:   Paracoccidioides brasiliensis </li></ul><ul><li>Location :   Central and South...
Questions <ul><li>Aspergillus </li></ul><ul><ul><li>Give an account: normal habitat, risk factors, spectrum of disease, la...
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aspergillus lecture

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aspergillus lecture

  1. 1. Aspergillosis and Systemic mycoses R Lin NP/09
  2. 2. Fungal infections <ul><li>Most fungal infections are opportunistic – candida is the most common causing skin and soft tissue infection </li></ul><ul><ul><li>Severe infection (mucous membrane, oesophagus) in AIDS </li></ul></ul><ul><ul><li>Systemic infection in neutropenic </li></ul></ul><ul><li>Aspergillus </li></ul><ul><ul><li>Opportunistic, and affects the most severely neutropenic </li></ul></ul>
  3. 3. Aspergillosis <ul><li>Found in the air all around us </li></ul><ul><li>Harmless to normal people </li></ul><ul><li>Opportunistic disease in the immunocompromised patient </li></ul><ul><ul><li>Severe neutropenia </li></ul></ul><ul><ul><li>Debilitating disease </li></ul></ul><ul><ul><li>Disruption of normal flora </li></ul></ul><ul><ul><li>Antibiotics, steroids </li></ul></ul><ul><ul><li>Abnormal lung e.g. bronchiectasis, cancer </li></ul></ul>
  4. 4. Spectrum of disease <ul><li>Colonization : sinuses, lungs </li></ul><ul><li>Toxicosis : aflatoxin ( A. flavus ) </li></ul><ul><li>Allergic bronchopulmonary aspergillosis : sinuses, lungs </li></ul><ul><li>Pulmonary aspergilloma : pre-existing lung cavity </li></ul><ul><li>Invasive aspergillosis : pulmonary, sinonasal, CNS, endocarditis, renal </li></ul><ul><li>Others e.g. otomycosis ( A. niger ) </li></ul>
  5. 5. Invasive aspergillosis <ul><li>Most commonly in severely neutropenic e.g. after bone marrow transplant </li></ul><ul><li>Portal of entry: sinuses, lungs </li></ul><ul><li>Difficult to diagnose </li></ul><ul><ul><li>Clinical suspicion, radiology, laboratory tests </li></ul></ul><ul><li>Difficult to treat </li></ul><ul><ul><li>Amphotericin B, voriconazole, itraconazole </li></ul></ul><ul><ul><li>Surgical resection </li></ul></ul><ul><li>Poor outcome </li></ul>
  6. 6. Laboratory investigation <ul><li>Microscopy: KOH prep, sputum, bronchoalveolar lavage </li></ul><ul><li>Histology : lung </li></ul><ul><li>Culture : sputum (contaminant?), BAL, tissue </li></ul><ul><li>Galactomannan EIA </li></ul><ul><li>PCR: 18sRNA gene, not always useful </li></ul>
  7. 7. Galactomannan EIA <ul><li>Monitor post-transplant patient 2x / week </li></ul><ul><li>Rising value or high value + symptoms </li></ul><ul><li>False-positives </li></ul><ul><ul><li>Penicillin-containing antibiotic </li></ul></ul><ul><ul><li>Milk, cereals </li></ul></ul>
  8. 14. TRUE SYSTEMIC (ENDEMIC) MYCOSES <ul><li>Coccidioidomycosis </li></ul><ul><li>Histoplasmosis </li></ul><ul><li>Blastomycosis </li></ul><ul><li>Paracoccidioidomycosis </li></ul>
  9. 15. TRUE SYSTEMIC MYCOSES General features <ul><li>Causative agents: thermally dimorphic fungi that exist in nature, soil </li></ul><ul><li>Geographic distribution varies </li></ul><ul><li>Inhalation  pulmonary INFECTION  dissemination </li></ul><ul><li>No evidence of transmission among humans or animals </li></ul><ul><li>Otherwise healthy individuals are infected </li></ul>
  10. 16. Endemic mycoses <ul><li>Geographical location; h/o travel ; except histoplasmosis (worldwide) </li></ul><ul><li>Clinical suspicion: liver/spleen/lungs/ mucocutaneous </li></ul><ul><li>Most cases asymptomatic </li></ul><ul><li>Route of infection: through lungs or direct inoculation of skin </li></ul><ul><li>Cause skin lesions, pneumonia, liver/spleen </li></ul>
  11. 17. Tests for systemic mycoses <ul><li>Microscopy </li></ul><ul><li>Fungal culture (2 temperatures!) </li></ul><ul><li>Tissue: histopathology </li></ul><ul><li>Serology – often older methods like immunodiffusion, complement fixation </li></ul><ul><li>Skin test of limited value </li></ul><ul><li>Others: urinary antigen (e.g. histoplasma) </li></ul>
  12. 18. COCCIDIOIDOMYCOSIS <ul><li>Aetiology : Coccidioides immitis </li></ul><ul><li>Location : Confined to southwestern US, northern Mexico, Central and South America </li></ul><ul><li>Microscopy. : </li></ul><ul><li>- Tissue (37°C): Spherules filled with endospores </li></ul><ul><li>-25°C: hyphae, barrel-shaped arthroconidia </li></ul>
  13. 19. Case history A 71-year-old male subject regularly spends several winter months in Arizona to play golf in the sun. Last March he experienced a gradual onset of fever and a headache, followed by a non-productive cough, myalgia and profound fatigue. His local physician diagnosed bronchopneumonia on chest radiograph, and prescribed azithromycin. The antibiotic provided no benefit, and ultimately the patient received two more courses of different empiric antibiotics. He returned home with continued cough and fatigue, even though the fever had abated somewhat. Two months following the initial onset of symptoms, a bronchoscopy was performed, and cultures grew Coccidioides species.
  14. 20. Other presentations Months to years following a symptomatic or asymptomatic infection, the affected lung may show complete resolution or an area of calcified or uncalcified pulmonary nodule similar radiographically to cancer. Microscopic examination of excised tissue identifies the organism. Occasionally the nodule liquefies to form a thin-walled cavity, which may close spontaneously or remain and become a nidus for suprainfection or spontaneous pneumothorax. Extrapulmonary dissemination can be identified in nearly all tissues, although skin and soft tissue, bones and meninges are the most common sites of dissemination. Chronic fibrocavitary pneumonia is seen infrequently, with chronic cough and dyspnoea, night sweats and weight loss, and lung fibrosis with thick-walled cavities. From BMJ Best Practice
  15. 21. Coccidioides immitis
  16. 22. Coccidioides immitis
  17. 23. Disseminated coccidioidomycosis
  18. 24. Histoplasma capsulatum
  19. 25. HISTOPLASMOSIS <ul><li>Aetiology: Histoplasma capsulatum </li></ul><ul><li>Natural reservoir: soil, bat and avian habitats </li></ul><ul><li>Location: May be prevalent all over the world, but the incidence varies widely </li></ul><ul><li>Microscopy </li></ul><ul><ul><li>Yeast cell in tissue (37°C) </li></ul></ul><ul><li>- Hyphae, microconidia and macroconidia (tuberculate chlamydospore) at 25 °C </li></ul>
  20. 26. Histoplasma capsulatum
  21. 27. Histoplasma
  22. 31. Blastomyces dermatitidis
  23. 32. BLASTOMYCOSIS <ul><li>Aetiology : Blastomyces dermatitidis </li></ul><ul><li>Location : America, Africa, Asia </li></ul><ul><li>Micr oscopy: </li></ul><ul><ul><li>-Yeasts at 37°C </li></ul></ul><ul><ul><li>bud is attached to the parent cell by a broad base </li></ul></ul><ul><li>-Hyphae and conidia at 25 °C </li></ul>
  24. 33. Blastomycosis
  25. 34. Paracoccidioides brasiliensis
  26. 35. PARACOCCIDIOIDOMYCOSIS <ul><li>Aetiology: Paracoccidioides brasiliensis </li></ul><ul><li>Location : Central and South America </li></ul><ul><li>Pathogenesis : Inhalation of conidia </li></ul><ul><li>Microscopy .: At 37°C (in tissue ): multiply budding yeasts; the buds are attached to the parent cell by a narrow base </li></ul><ul><li> At 25 °C: hyphae and conidia </li></ul>
  27. 36. Questions <ul><li>Aspergillus </li></ul><ul><ul><li>Give an account: normal habitat, risk factors, spectrum of disease, lab tests </li></ul></ul><ul><li>Endemic mycosis </li></ul><ul><ul><li>How does one diagnose? Types of lab tests? </li></ul></ul><ul><ul><li>Why is it important to know? </li></ul></ul>

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