Flashcards in Week 10 - Opportunistic and systemic fungal infections Deck (19)
Which are the most common moulds causing systemic infection in humans?
Aspergillus, Zyomycetes, Fusarium and Scedosporium
What are the most common yeasts causing systemic infection in humans?
Candida and Cryptococcus
What are the most common dimorphic fungi causing systemic infection in humans?
Histoplasma, Sporothrix, Blastomyces
Which are the typical patient groups at risk for systemic fungal infections?
Anyone who is immunocompromised: organ transplant recipients, AIDS, immunosuppressant therapy, haematological stem cell transplant recipients
If you have a humoral deficiency, what infections are you most likely to get?
Encapsulates bacteria i.e. Streptococcus pneumoniae, Neisseria meningitides
Describe a zygomycete mould
Has broad hyphae that looks like ribbons
Displays rapid growth
Has sporing bodies
How do you treat Zygomycetes infections?
Intravenous liposomal amphotericin
Which site is the most common for invasive mould infections, and what are characteristic signs the look for?
Imaging should show: halo signs, air crescent signs and reverse halo signs
What is the differential diagnosis for sub-acute mononuclear meningitis?
What will Cryptococcal meningitis look like if stained?
-Stain with india ink
-round yeasts with surrounding capsule
What type of organism are fungi?
Eurkaryote. This has implications when looking at treating with antifungal drugs
Describe some features of rhinocerebral mucormycosis
This is a rare infection of the sinuses, nasal passages, oral cavity and brain caused by saprophytic fungi.
Often affects immunocompromised or diabetics
Describe the manifestation of invasive pulmonary aspergillious
Occurs when infection spreads rapidly from the lungs to the brain, heart, kidneys and skin. Symptoms include fever and chills, blood streaked sputum, headaches/eye symptoms, nosebleeds, unilateral facial swelling and skin lesions
What does a positive india ink result mean?
This test is used ot detect Cryptococcus neoformans in wet preparations. A positive result means that C.neoformans is present
How do you normally acquire cryptococcosis and what are the three presentations?
Via inhalation. It's often asymptomatic.
What are some features of CNS cryptococcosis?
Usually present with meningitis or meningoencephalitis, headache, seizures or blurred vision due to raised intracranial pressure
What host factors predispose you to candidaemia?
Neutropenia, marked immunosuppression, recent surgery, antibiotics
What are some manifestations of systemic candidiasis?
Candidaemia + organ invasion. Candida produces nodules, abscesses and tissue destruction in the organs it settles in