A IRBORNE I NFECTION. A IRBORNE INFECTIONS : Contracted by inhalation of microorganisms or spores...
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Transcript of A IRBORNE I NFECTION. A IRBORNE INFECTIONS : Contracted by inhalation of microorganisms or spores...
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 abuse
Most 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 hyphae
The 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