Asperigillus spp, Mucormycosis, Pneumocystis spp (Moulds)

Question 1

Diagnosis of Aspergillosis

Answer 1

Mould – branched (acute, 45° angles), septate hyphae

Test :
1) Tissue biopsy and microscopy (acute angled, septate hyphae) –> for Invasive Aspergillosis
2) culture
3) Invasive & Disseminated disease –>
(+) galactomannan antigen in serum or β-D-glucan test

*Hyphae stain well with PAS, Gomori Methenamine
Silver & Gridley stains –> treelike branching at acute (≈45-degree) angles

Question 2

Transmission of Aspergillosis

Answer 2

food soil, water, food & air, esp. decaying vegetation, usual route of infection is
–> inhalation of conidia in lungs or sinuses

Question 3

Clinical manifestations of Aspergillus spp

Answer 3

1) Aspergillosis
2) Allergic Broncho-Pulmonary Aspergillosis (ABPA) –> Suceptiable patients are Asthma and CF
3) Aspergilloma:fungus ball in the lungs
4) Invasive Aspergillosis (susceptiable patients: Nutropenic patients, HSCT or lung transplant)
5) Sinusitis –> may enter the CNS

*HSCT: (Haemopoietic stem cell transplantation

Question 4

Clinical syndroms of invasive Pulmonary Aspergillosis

Answer 4

1) RARELY before 10-12d of profound neutropenia
2) Progressive dry cough, dyspnea, pleuritic chest pain, fever despite broad-spectrum antibiotics &
pulmonary infiltrates

Question 5

characteristic feature seen in a CT scan of a patient with Invasive Pulmonary Aspergillosis

Answer 5

nodular lesions surrounded by “halo”

Question 6

diagnosis of Mucormycosis (Rhizopus, Mucor)

Answer 6

–> Molds with sparsely septate hyphae, spores in a sac structure called sporangium (spores easily
aerosolized & inhaled or inoculated into skin)

(Tissues: ribbon-like, sparsely septate hyphae – TYPICALLY ANGIOINVASIVE, stain with H/E, Gomori silver & other fungal stains)

Question 7

Transmission of Mucormycosis

Answer 7

found in decaying bread, fruits & vegetables –> Inhalation of spores, ingestion or contamination of wounds
* extremely devastating & lethal

Question 8

• Invasive disease occurs in immunosuppressed.
  what are the Risk Factors of Mucormycosis?

Answer 8

1. POORLY CONTROLLED DM (both 1 & 2) AND METABOLIC ACIDOSIS
2. High dose prolonged corticosteroid Tx
3. Persistent neutropenia
4. In the past, administration of deferoxamine in those under chronic transfusions
5. Haematologic malignancies

Question 9

Clinical Manifestations of Mucormycosis

Answer 9

1) Rhinocerebral
–> Thrombosis & extensive necrosis , extend from hard palate to sinuses, reach CNS - may invade the eye causing orbital disease
* EXTREMELY DEADLY & DISFIGURING
2) Pulmonary disease
3) Skin & Soft tissue infections ( open wounds)

Question 10

diagnosis of P.jirovecii

Answer 10

Unicellular fungi that Lacks ergosterol

Tests:
1) Microscopy
–> Giemsa stain for trophic forms, Gomori Silver & toluidine blue for cysts
2) PCR : BAL , induced sputum &nasopharyngeal aspirates
3) Serum 1, 3 β-D glucan –>Useful for ruling out PCP, high NPV (almost 95%)
4) Imagnig (CT) –> “Ground-glass” Opacities

Question 11

Characteristic features seen in a CT scan of a patient with PCR (Pneumocystis Pneumonia)

Answer 11

“Ground glass” opacities

Question 12

Transmission of P.Jiroveccii?

Answer 12

Inhalation of Respiratory droplets
–> Infants are the main target

Question 13

Clinical Manifesations of P.Jirovecii ?

Answer 13

PCP- Pneumocyctis Pneumonia
Symptoms: progressive exertional dyspnea, tachypnea, low grade fever, non-productive cough
- Important: Haemoptysis (coughing up blood) NOT a feature

Question 14

PCP Suseptable patients ?

Answer 14

HIV (+)