Systemic mycoses

• What are systemic mycoses primarily associated with?

  Fungal infections of internal organs
• How do systemic mycoses infections typically occur?

  By inhalation of air-borne conidia
• What percentage of systemic mycoses are self-limiting and asymptomatic?

  More than 95%
• What route do symptomatic systemic mycoses disseminate by?

  Haematogenous route
• What type of fungi primarily cause systemic mycoses?

  Dimorphic fungi
• Which fungi are included in systemic mycoses?

  Histoplasma capsulatum, Blastomyces dermatitidis
• What are opportunistic mycotic infections?

  Systemic infections in immunocompromised patients
• What is histoplasmosis caused by?

  Histoplasma capsulatum
• What is another name for histoplasmosis?

  Darling’s disease
• Where is histoplasmosis endemic?

  Parts of the USA
• What is the primary habitat of Histoplasma capsulatum?

  Soil, rotten areas, and bird feces
• How does histoplasmosis enter the body?

  Through inhalation of conidia or mycelial fragments
• What happens to inhaled conidia in the body?

  They convert into yeast in alveolar macrophages
• What type of inflammation does histoplasmosis cause?

  Granulomatous inflammation
• What are the two types of granulomas that may form?

  Caseating or non-caseating granulomas
• What does dissemination to the reticuloendothelial system involve?

  All phagocytic cells of the RES
• What are the clinical types of histoplasmosis?

  Pulmonary, cutaneous, and disseminated
• Who is at greater risk for disseminated histoplasmosis?

  Children below 2 years and individuals with HIV
• What specimens are used for laboratory diagnosis of histoplasmosis?

  Sputum, bone marrow, lymph nodes
• What does a blood smear reveal in histoplasmosis diagnosis?

  Small oval yeast-like cells within phagocytes
• What staining methods are used for direct examination?

  Giemsa or Wright’s stain
• What culture media are used for fungal culture of histoplasmosis?

  SDA and BHI at 25C and 37C
• What do fungal cultures of histoplasmosis show?

  White cottony mycelia and spherical spores
• What is the histoplasmin skin test used for?

  To test for histoplasmosis infection
• What is a significant serological test result for histoplasmosis?

  LA titre of 1:32 or higher
• What is the treatment for disseminated histoplasmosis?

  Amphotericin B
• What is the preventive measure for histoplasmosis?

  Regular cleaning of farm buildings
• What is another name for blastomycosis?

  Gilchrist or Chicago disease
• What causes blastomycosis?

  Inhalation of spores of Blastomyces dermatitidis
• What type of infection does blastomycosis cause?

  Suppurative and granulomatous infection
• What are the clinical types of blastomycosis?

  Pulmonary, cutaneous, and disseminated
• What is the commonest form of cutaneous blastomycosis?

  Seen over exposed parts like face
• What specimens are used for laboratory diagnosis of blastomycosis?

  Sputum, bronchoalveolar lavage, biopsy
• What does a wet mount reveal in blastomycosis diagnosis?

  Thick-walled, multinucleate giant yeast cells
• How long does fungal culture for blastomycosis take?

  2 to 4 weeks
• What do cultures at 37C show for blastomycosis?

  Budding yeast cells
• What is the treatment for life-threatening blastomycosis infections?

  Amphotericin B
• What is coccidioidomycosis caused by?

  Coccidioides immitis
• What is the primary route of infection for coccidioidomycosis?

  Inhalation of arthroconidia
• What are the clinical features of coccidioidomycosis?

  Influenza-like fever, Valley fever