Lecture 10 Fungal Infections Flashcards Preview

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Flashcards in Lecture 10 Fungal Infections Deck (19)
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1
Q

What type of patients are susceptible to fungal infections

A

Affecting patients with an impaired immune system (Immunodeficient, HIV/AIDS, neutropenia, premature neonates)

Affecting patients with chronic lung diseases (asthma, CF,COPD)

ICU patients

2
Q

What are the causes of mucocutaneous candidiasis

A

Antibiotic use
Moist areas
Inhalation steroids
Neonates <3 months

3
Q

Presenting symptoms of Mucocutaneous

A

Neutropenia
Low CD4+ T cells
Impaired IL-17 Immunity

4
Q

What are the causes of Invasive Candidiasis

A

Gut commensal

Infections mostly endogenous origin

5
Q

Risk Factors of Invasive Candiasis

A

Broad-spectrum antibiotics Intravascular catheters
Total parenteral nutrition
Abdominal surgery

6
Q

How is Invasive Candidiasis diagnosed

A

Blood culture or culture from normally sterile site

7
Q

How is Aspergillus transmitted

A

Sporulation
Hydrophobic conidia
Airborne/inhalation

8
Q

What are the clinical features of acute invasive pulmonary aspergillosis

A

Rapid and extensive hyphal growth
• Thrombosis and hemorrhage
• Angio-invasive and dissemination
• Absent or non-specific clinical signs and symptoms
• Persistent febrile neutropenia despite broad-spectrum antibiotics

9
Q

What are the clinical features of (Sub) acute invasive pulmonary aspergillosis

A
 Non-angioinvasive
 Limited fungal growth
 Pyogranulomatous infiltrates
 Tissue necrosis
 Excessive inflammation
 Non-specific clinical signs and symptoms  Mild to moderate systemic illness
10
Q

How is Pulmonary Aspergillosis diagnosed in non-neutropenic patients

A

Cultures of sputum and/or bronchoalveolar lavage, and/or biopsy
• Aspergillus specific IgG and IgE in chronic and allergic pulmonary aspergillosis

11
Q

How is Pulmonary Aspergillosis diagnosed in neutropenic patients

A

High resolution CT-chest
 ‘halo-sign’ and ‘air-crescent sign’
• Molecular markers in blood: galactomannan and PCR-Aspergillus (high NPV and are suited for screening purposes)
• BAL and biopsies if clinical condition allows

12
Q

How is cryptococcus transmitted

A

Inhalation

Found on the bark of a variety of tress, bird faeces and organic matter

13
Q

Clinical presentation of cryptococcus infection

A
Headache
Confusion
Altered behaviour
Visual disturbance
Coma
14
Q

What is the diagnosis of cryptococcal disease

A

CSF- high protein and low glucose

Bood culture- cryptococcus antigen

15
Q

Name antifungal agents to treat invasive fungal infections

A

Amphotericin B formulations (iv)
Azoles (iv, oral)
Echinocandins (iv)
Flucytosine (iv, oral)

16
Q

What is the action of Amphotericin B formulations (iv)

A

Acting on ergosterol > lysis

Cryptococcal meningitis

17
Q

What is the action of Azoles

A

Inhibiting ergosterol synthesis

Invasive aspiergillosis

18
Q

What is the action of Echinocandins

A

Inhibiting glucan synthesis

Invasive candidiasis

19
Q

What is the action of Flucytosine (iv, oral)

A

Inhibiting fungal DNA synthesis

Cryptococcal meningitis