LECTURE 3 dr. Jane

• Classification of deep mycoses

  • Site of infection
  • Route of acquisition: exo or endogenous origin
  • Type of virulence: primary or opportunistic pathogen

  
• Primary systemic fungal pathogens

  • Coccidioides immitis
  • Histoplasma capsulatum
  • Blastomyces dermatitidis
  • Paracoccidioides brasiliensis

  
• Opportunistic fungal pathogens


  • Cryptococcus neoformans
  • Candida spp.
  • Aspergillus spp.
  • Penicillium marneffei
  • The Zygomycetes
  • Trichosporon beigelii
  • Fusarium spp.

  
• Candidiasis is an important opportunistic fungal infection

  
• Diagnosis of invasive candidiasis is challenging as there are no specific clinical signs or symptoms

  
• Invasive candidiasis should be suspected in patients with known risk factors who have an unexplained fever unresponsive to antibacterial treatment

  
• Cryptococcosis is mostly seen in HIV infected persons
• Cryptococcus neoformans kills 650,000 immunocompromised people suffering from HIV/AIDS every year worldwide
• Mucormycosis is an emerging fungal infection with increasing incidence
• Risk factors for mucormycosis

  • Diabetes mellitus (with or without ketoacidosis)
  • Hematological malignancies
  • Other malignancies
  • Transplantation
  • Neutropenia
  • Steroid use
  • Trauma
  • Iron overload
  • IV drug use
  • Prematurity
  • Malnutrition
  • Immunocompetent with direct inoculation in the skin
• Rhizopus spp., Lichteimia spp. and Mucor spp. are the most common causative agents of mucormycosis (75% of cases)
• Specimen collection for diagnosis of mucormycosis should be done carefully, avoiding crush or grind, and sent to the lab as soon as possible