ASPERGILLOSIS.pdf

Aspergillosis invasive and allergic disease caused by a hyaline mold named aspergillus.
Pathogenesis
Risk factor
Clinical manifestation
Clinical manifestation
Lab diagnosis
Direct examination
Culture
Antibody detection
Antibody detection

1. Insha jan

2. •Aspergillosis refers to the invasive and allergic diseases caused
by a hyaline mold named Aspergillus.
•There are nearly 35 pathogenic and allergenic species of
Aspergillus, important ones being-A. fumigatus, A. flavus and A.
niger.

3. •Aspergillus species are widely distributed in nature, most commonly
growing on decaying plants, producing chains of conidia.
•Transmission occurs by inhalation of airborne conidia.
• Risk factors for invasive aspergillosis are:
• Glucocorticoid use (the most important risk factor)
•Profound neutropenia
•Neutrophil dysfunction
•Underlying pneumonia,
•chronic obstructive pulmonary disease,
•tuberculosis or sarcoidosis
•Anti-tumor necrosis factor therapy.

4. •The incubation period varies from 2 to 90
days.
•Depending upon the site of involvement,
Aspergillus produces various clinical
manifestations such as:
• Pulmonary aspergillosis: It is the most
common form of aspergillosis; includes
various manifestations such as:
• Allergic bronchopulmonary aspergillosis
(ABPA)
•Severe bronchial asthma
• Extrinsic allergic alveolitis
• Aspergilloma (fungal ball)
• Acute angioinvasive pulmonary aspergillosis

5. •Other forms of aspergillosis include:
•Invasive sinusitis
• Invasive sinusitis (acute and chronic form)
• Chronic granulomatous sinusitis
• Maxillary fungal ball
•Allergic fungal sinusitis
•Cardiac aspergillosis: Endocarditis (native or prosthetic) and
pericarditis
•Cerebral aspergillosis: Brain abscess, hemorrhagic infarction,
and meningitis

6. •Ocular aspergillosis: Keratitis and
endophthalrnitis
• Ear infection: Otitis externa
• Cutaneous aspergillosis: Direct invasion of the
skin occurs in neutropenic patients at the site of
IV catheter insertion and in burns patients
•Nail bed infection: Onychomycosis
•Mycotoxicosis: Various Aspergillus species
produce several fungal toxins; e.g. A. flavus
produces aflatoxin, which causes liver
carcinoma

7. •A. fumigatus accounts for most of the cases of acute pulmonary
and allergic aspergillosis.
• A. flavus is more common in hospitals and causes more sinus,
skin and ocular infections than A. fumigatus
•A. niger can cause invasive infection but more commonly
colonizes the respiratory tract and causes otitis externa.

8. •Specimens such as sputum and tissue
biopsies may be collected.
• Direct Examination KOH (10%) mount or
histopathological staining of specimens
reveals characteristic narrow septate
hyaline hyphae with acute angle branching.
•Culture
•Specimens are inoculated onto SDA and
incubated at 25°C. Species identification is
done based on macroscopic and
microscopic (LPCB mount) appearance of
the colonies

9. •Colonies consist of hyaline septate
hyphae from which conidiophores arise
which end at vesicles. Vesicles are either
tubular or globular in shape
•From the vesicle, finger-like projections
of conidia producing cells arise called
phialides or sterigmata. Phialides are
arranged either in one or two rows, the
first row is called metulae.
•Conidia arise from the vesicles either on
their entire surface or only on the upper
half.

10. •Antigen Detection
•ELISA (kinetic ELISA) detecting Aspergillus specific
galactomannan antigen in patient's sera or urine is useful for
establishing early diagnosis.
•Antibody Detection
•Detection of serum antibodies is very useful for chronic invasive
aspergillosis and aspergilloma, where the culture is usually
negative. Titer falls rapidly following clinical improvement.
• In allergic syndromes such as ABPA and severe asthma, specific
serum IgE levels are elevated.

11. •Detection of Metabolites
• Detection of β-1-3-D-glucan (by G test) or mannitol (by gas
liquid chromatography) is useful alternative for establishing the
diagnosis, particularly when the culture is negative.
•Skin Test
•Positive skin test to various antigen extracts of Aspergillus
indicates hypersensitivity response and is usually positive for
various allergic type of aspergillosis.

12. •Following are the first line treatment recommended in different
forms of aspergillosis.
• For invasive aspergillosis-voriconazole is the drug of choice. o
For ABPA-itraconazole is the drug of choice.
• For single aspergilloma-surgery is indicated.
• For chronic pulmonary aspergillosis-itraconazole or
voriconazole is the drug of choice.
• For prophylaxis, posaconazole is indicated.