AIRBORNE INFECTION
AIRBORNE INFECTIONS:
Contracted by inhalation of microorganisms or
spores suspended in air on water droplets or
dust particles
RESPIRATORY TRACT INFECTIONS
Infections involving the respiratory tracts
Classified as an upper respiratory tract or a lower
respiratory tract infections
Lower respiratory infections, such as pneumonia,
tend to be far more serious conditions than upper
respiratory infections, such as the common cold
URTI
Infections in the: Nose
Sinuses
Pharynx
Larynx
Middle ear
URTI TYPICAL INFECTIONS Tonsillitis Pharyngitis Laryngitis Sinusitis (can be cause by fungi) Otitis media (can be cause by fungi) Influenza Common cold
SYMPTOMS OF URTIS Cough Sore throat Runny nose Nasal congestion Headache Low grade fever Sneezing
FUNGAL INFECTIONS OF THE UPPER RESPIRATORY TRACTS
FUNGAL INFECTIONS OF THE UPPER RESPIRATORY TRACTS Fungal Ear infections
Fungal nasal sinusitis
Fungal infections of the oral cavity
Fungal keratitis
FUNGAL EAR INFECTIONS“OTOMYCOSIS”Otitis externa & Otitis media
OTITIS EXTERNA
Fungal infection of the external ear canal
World-wide, but more common in tropical and sub-tropical regions
ETIOLOGY Caused mainly by:
Aspergillus fumigatus
Aspergillus niger
Candida albicans
Candida tropicalis
OTHER CAUSES MAY INCLUDE
Malassezia species
Pseudallescheria boydii
Absidia species
Acremonium species
Penicillium species
Rhizopus species
Scopulariopsis brevicaulis
CLINICAL MANIFESTATION Inflammation Itching Scaling Discomfort Masses of debris containing hyphae Pain
Otitis Externa
LABORATORY DIAGNOSIS Direct examination of epithelial debris
Hyphae and in some instances the fruiting structures of the etiologic agent
Culture: Sabouraud dextrose agar incubated at 30°C
(without cycloheximide)
MANAGEMENT
Removal of debris and cleaning
Topical azole cream
Gauze packs soaked in amphotercib B +
natamycin or imidazole
FUNGAL PARANASAL SINUSITIS
FUBGAL PARANASAL SINUSITIS
Sinusitis caused by different fungi
Especially in patients with a history of allergic rhinitis or immunosuppression
CAUSATIVE AGENTS Dematiaceous fungi (phaeohyphomycosis):
Bipolaris species Curvularia species Alternaria species
Non Dematiaceous fungi (haylohyphomycosis): Aspergillus species Zygomycetes
Curvularia geniculata (Atlas of Clinical Fungi, De Hoog et al. 2000)
Curvularia lunata
Bipolaris
Alternaria
Zygomycetes
Zygomycetes
Zygomycetes in tissues
MANAGEMENT OF PARANASAL SINUSITIS
Surgery
Antifungal (Amphotericin B or Azoles)
ORAL THRUSHOral candidiasis or candidosis
ORAL CANDIDIASIS OR CANDIDOSIS (ORAL THRUSH) Over growth of C. albicans in the oral cavity Whitish removable layer cover reddish,
eroded, easily bleeding mucosa May extend to the esophagus Mainly seen in:
Prolonged use of broad spectrum antibiotics Impaired T-cell immunity
Oral candidiasis
TREATMENT
For healthy adults and children
Eating unsweetened yogurt
Taking acidophilus capsules or liquid
For adults with weakened immune
systems
Azoles
Amphotericin B
KERATOMYCOSISmycotic keratitis
KERATOMYCOSIS Corneal infection caused by either filamentous fungi or
yeast The most important risk factors:
Trauma (generally with plant material) Chronic ocular surface diseases Contact lens usage Surgery Eye-drops abuse Immunodeficiencies
Condition related to warm climates
Keratitis
Fungi type Moulds Yeasts
Predisposing factors • Outdoor or vegetable-related trauma
• Contact lens usage • Eye surgery
• Chronic ocular surface diseases
• Chronic mucocutaneous candidiasis
• Immunosuppression, including AIDS
• Corneal anesthetic abuseMost common
etiologic agents
• Fusarium spp • Aspergillus spp • Acremonium • Other
• Candida albicans • Candida parapsilosis • Candida tropicalis
EPIDEMIOLOGICAL AND CLINICAL DIFFERENCES BETWEEN THE TWO FORMS OF THE INFECTION
LABORATORY DIAGNOSIS Microscopic examination
Hyphae in corneal scrapings
Fungi are usually deep within the corneal structure, not on the surface.
Extensive debridement may be necessary to obtain satisfactory clinical material (swabs are unsatisfactory)
Septate hyphaeThe fungus was seen in several repeated corneal samplings
MANAGEMENT
Drug of choice is Natamycin
Amphotericin B a second alternative
Systemic therapy with azoles
Surgery may be necessary
LOWER RESPIRATORY TRACTS INFECTIONS
LOWER RESPIRATORY TRACTS INFECTIONS
Generally more serious than upper
respiratory infections
The leading cause of death among
all infectious diseases
The two most common LRIs: Bronchitis and pneumonia
PNEUMONIA
Pneumonia is an inflammatory condition of
the lung
Especially affecting the microscopic air sacs
(alveoli)
Associated with fever, chest symptoms, and a
lack of air space (consolidation) on a chest X-ray
CAUSES
Microbial infections: Bacteria,
Viruses
Fungi
Parasites
Other causes
TYPICAL SYMPTOMS Cough
Chest pain
Fever
Difficulty breathing
DIAGNOSIS
X-rays
Sputum examination
CLASSIFICATION Community-acquired Aspiration Hospital-acquired Ventilator-associated pneumonia
Lobar pneumonia Bronchial pneumonia
By the causative organism
CAUSATIVE AGENTS Viruses and bacteria (most common) Fungi and parasites (less common)
Mixed infections with both viruses and bacteria: Up to 45% of infections in children 15% of infections in adults
Causative agent is not isolated in approximately half of cases
FUNGAL PNEUMONIA
FUNGAL PNEUMONIA
Uncommon
Occur in individuals with weakened immune
systems due to: AIDS
Immunosuppressive drugs
Other medical problems
FUNGAL SPECIES Opportunistic:
Aspergillus species Candida species Pneumocystis jiroveci
Primary: Histoplasma capsulatum Blastomyces dermatitidis Coccidioides immitis
ASPERGILLUS SPECIES Pulmonary Aspergillosis:
Allergic, aspergilloma and invasive aspergillosis
The common etiological agents are: Aspergillus fumigatusAspergillus flavusAspergillus nigerAspergillus nidulansAspergillus terreus
Aspergillosis of the lung Methenamine silver stained tissue section showing
dichotomously branched, septate hyphae (left) and a conidial head of A. fumigatus (right)
Aspergillus species
OTHER OPPORTUNISTIC FUNGAL INFECTIONS:CANDIDA SPECIES
C. albicans (50-60 % of all yeast infections)
C. glabrata C. tropicalis C. parapsilosis
Candida albicans in the lung of an immunocompromised patient, PAS stain
Pneumocystis jiroveci
PNEUMOCYSTIS JIROVECII
Yeast-like fungus of the genus Pneumocystis
Pneumocystis pneumonia
Prior to its discovery as a human-specific pathogen, P. Jirovecii was known as P. carinii
PATHOGENICITY AND CLINICAL SIGNIFICANCE Pneumocystis is one of the major causes of
opportunistic mycoses in immunocompromised
Clinical forms: Asymptomatic infections Infantile (interstitial plasma cell) pneumonia Pneumonia in immuno-compromised host Extra-pulmonary infections
DIAGNOSIS OF P. JIROVECI PNEUMONIA
Depend of morphologic identification
Culture is difficult
Trophic (trophozoite)
Intracystic spores
Pneumocystis jiroveci morphology
The cysts of P. jiroveci are spherical in shape and measure approximately 4-7 µm
Gomori's Methenamine Silver Stain
X 1000
Cysts of Pneumocystis jiroveci in lung tissue GMS stain
The walls of the cysts are stained black and often appear crescent shaped or like crushed ping-pong
balls
Pneumocystis jiroveci and artifacts
Yeast cells Pneumocystis jiroveci
Pneumocystis in induced sputum; wright stain stains
trophozoites
Pneumocystis in bronchoalveolar lavage;
toluidine blue highlights cyst forms
END
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