Fungal Infections of Respiratory Tract Flashcards
1
Q
Sinuses - organism and disease:
A
zygomycetes – mucormycosis
2
Q
oral cavity - organism and disease:
A
candida –> thrush, esophagitis
3
Q
lungs - organisms and diseases:
A
Histoplasma —> Histoplasmosis
Blastomyces –> Blastomycosis
Paracoccidioides —> paracoccidioidomycosis
Coccidioides —-> Coccidioidomycosis
Cryptococcus –> Cryptococcosis
Pneumocystis —> PCP (immunodef)
Aspergillus —> Aspergillosis (immunodef)
4
Q
Zygomycoses (Mucormycosis) - where it can be found and who it may affect
A
- Sinus infections
- Ubiquitous in the environment found
- Soil, vegetation and food (fruits and bread)
- Predisposing factors: immunosuppression, diabetes, and burns
- Infection is rare in normal healthy individuals
- potentially fatal
5
Q
Zygomycetes types:
A
- Rhizopus
- Absidia
- Mucor
6
Q
term for fungi that can grow as both molds and yeast=
A
dimorphic - transition depending on environment
7
Q
india ink test used to identify:
A
cryptococcus neoformans
8
Q
features of -Rhizopus -Absidia -Mucor
A
- non-septate hyphae
- sporangia bearing sporangiospores
9
Q
most common form of zygomycosis=
A
Rhinocerebral zygomycosis
10
Q
Rhinocerebral zygomycosis disease details
A
- Primarily in diabetic patients
- immunocompromised patients and burn patients get this too
- Infection originates in the sinuses (inhalation of spores)
- Extends to neighboring tissues (nose, adjacent sinuses, the hard palate, eye, and brain)
- can also be introduced into the GI tract, lungs, and skin.
- Initial symptoms include nasal congestion, blood-tinged rhinorrhea, tender sinuses, headache and fever
- Progress to facial or periorbital edema and visual disturbances
- Progression to the brain results in altered mental status, coma and death
11
Q
diabetic patients are more likely to get what fungal issue?
A
zygomycosis
12
Q
Zygomycetes (Mucormycosis) - diagnosis
A
- Observation of hyphal elements in clinical material
- Culture confirmation-grow rapidly
- In tissue section broad aseptate hyphae are frequently observed in blood vessels, frequently branching at right angles (90degrees)
13
Q
90 degree angles between septae in what organism?
A
Zygomycetes (Mucormycosis)
14
Q
Zygomycetes (Mucormycosis) -treatment
A
Amphotericin B
15
Q
Candidiasis what causes it? where is it found?
A
- Caused by several yeast of the genus Candida
- Most infections caused by C. albicans
- Considered normal flora : skin, mucus membranes, gastrointestinal tract
- Present in the environment- isolated from food and fomites
- Candida can exists in yeast, pseudohyphal, and hyphal forms
- Yeast = normal flora
- Hyphal forms = tissue
16
Q
which form of candida is a problem?
A
hyphal. yeast forst is normal flora
17
Q
Oral Candidiasis (Thrush) - who gets this?
A
ALTERED IMMUNE STATUS:
- Infants
- Adults (steroids, antineoplastic drugs, or antibiotics)
- AIDS patients
18
Q
Oral Candidiasis (Thrush) - clinical presentation
A
- Diffuse erythema and white patches on the surface of the buccal mucosa, throat, tongue, and gums.
- Plaques can be scraped or wiped away revealing a raw, erythematous, lesion.
- The white lesions are composed of yeast and pseudohyphal forms of C. albicans.
19
Q
Oral Candidiasis (Thrush) - Diagnosis
A
- Scrape it out of their mouth = direct observation of Candida in clinical material.
- Cultures generally not necessary: hard to distinguish between colonization and infection.
20
Q
Oral Candidiasis (Thrush) - Treatment
A
Oral formulations (mouth washes or lozenges) of nystatin and azole compounds
21
Q
Systemic Mycoses usually aqcuired by
A
inhalation
22
Q
Systemic Mycoses some details
A
- Diverse group of clinical presentations sub-clinical to progressive, debilitating disease.
- Not opportunistic fungi - they can cause disease in previously healthy individuals.(SEVERITY IS GREATER IF IMMUNODEF)
- All five of the fungi causing systemic mycosis are found in the environment
- Acquired by inhalation of fungal elements (hyphae or spores).
- All of the clinical syndromes begin with pulmonary infection.
23
Q
Dimorphic systemic mycoses
A
Histoplasma capsulatum
Blastomyces dermatitidis
Paracoccidioides brasiliensis
Coccidioides immitis
24
Q
Not dimorphic systemic mycoses
A
-Cryptococcus neoformans-encapsulated yeast in both the environment and man
25
Dimorphic systemic mycoses and where they are found?
THey have geograpical preference
- Histoplasma capsulatum - North and Central America - Mississippi and Ohio River Valleys
- Blastomycosis-Ohio and Mississippi river valley and to a lesser extent the Missouri and Arkansas river basins
- Paracoccidioidomycosis -South and Central America
- Coccidioides immitis - western hemishphere; San Joaquin Valley of Cali and Southern AZ
26
Most common worldwide systemic mycoses?
C. neoformans
27
Histoplasmosis region
-North and Central America - Mississippi and Ohio River Valleys = most people in these regions are 50-80% skin test positive
28
Histoplasmosis - caused by what fungi and what is this fungi associated with/where is it found?
- Caused by the dimorphic fungus Histoplasma capsulatum
- Found in soil under humid climate conditions
- Commonly found in soil containing bird and bat droppings.
- Can be isolated from bird and bat habitats such as chicken coops, attics, caves and city parks
- it can survive and replicate inside macrophages
29
Histoplasmosis- how do you get it?
- Infection is acquired by inhalation of micro- or macroconidia from the environment.
- Macroconidia of H. capsulatum have a characteristic tuberculate (round bump) appearance.
30
Histoplasmosis- clinical syndrome:
- Inhaled fungal spores are phagocytosed by pulmonary macrophages and convert to their yeast form.
- The organism can replicate within macrophages and spread through the lymphatic and reticuloendothelial system
- 95% of exposed people appear to be asymptomatic
31
Pulmonary histoplasmosis
- A mild flu-like illness with a dry cough, fever, and fatigue
- Develops several weeks after exposure and improves within 2 to 3 weeks
- Most infections resolve without any antifungal intervention
- Development of CMI (macrophage activation)
- Calcification of pulmonary lesions is common
- Pulmonary infiltrate and chest pain are more common in severe infections.
32
Chronic Pulmonary and Disseminated Histoplasmosis
- Typically in immuno-compromised individuals
- Disseminated disease: can be acute and life-threatening or chronic and debilitating
- Individuals experience fever, night sweats, anorexia, weight loss, and fatigue in addition to respiratory symptoms
- Hepatomegaly, splenomegaly, and lymphadenopathy due to the spread of organisms through the reticuloendothelial system
33
Chronic Pulmonary and Disseminated Histoplasmosis has similar symptoms to?
TB - fever, night sweats, anorexia, WL, fatigue, and respiratory symptoms
TB- has acid fast bacilli vs inside macrophages
34
Histoplasmosis - diagnosis
- Diagnosis
- direct observation of organisms (yeast form) in tissues or clinical samples (sputum)
- cultivation of organisms from clinical samples
- Serology (detect Ag or Ab)
- Detection of yeast forms in tissue or sputum samples is difficult due to their small size and lack of distinctive morphology.
- Cultures may take weeks to grow out and confirm dimorphism: grow as mold at 25 OC and yeast at 37 OC
35
Histoplasmosis - treatment:
- Amphotericin B for pulmonary and disseminated disease
- AIDS patients and other immunosuppressed individuals, often require lifelong suppressive therapy to prevent relapse (frequently with azoles (less toxic))
36
Blastomycosis where is it found regionally and in what enviroment?
- Ohio and Mississippi river valley and to a lesser extent the Missouri and Arkansas river basins
- Difficult to isolate from the environment, but thought to exist in moist soil high in decaying vegetation content
37
this disease can also present dogs and horses:
blastomycosis
38
Blastomyces dermatitidis what kind of fungus and soem features:
- dimorphic fungus
- Mold in the environment; yeast in tissues
- The yeast form of B. dermatitidis can be distinguished from those of H. capsulatum due to their larger size and very thick cell walls.
39
Blastomycosis - clinical manefestation
-Primarily a pulmonary disease, with the potential to disseminate causing ulcerative lesions of the skin, bone, and urogenital tract.
-Acquired through inhalation of spores from the environment
-Yeast can survive in macrophages and disseminate through the body
-Most infections are asymptomatic
-cough, fever, chest pain, sputum production
typically resolution without intervention
-->Disseminated disease
-Skin lesion - ulcerative and disfiguring
-Bone infection - necrosis and granuloma formation
-Prostate appears to be especially prone to infection.
40
fungal issues that tend to resolve on their own after a couple of weeks?
blastomycosis, COCCIDIOIDOMYCOSIS, and Histoplasmosis
41
Blastomycosis - Daignosis
- Observation of distinct yeast forms in sputum or biopsy material (thick cell wall - broad bud base)
- Cultivation may take 2-3 weeks (SLOW)
42
Blastomycosis - Treatment
- Amphotericin B
| - azole compounds for uncomplicated pulmonary disease
43
Paracoccidioidomycosis where is it found in the world, caused by and what kind of fungus is this?
- South and Central America
- Most common in MED - estrogen inhibits development
- Caused by Paracoccidioides brasiliensis- a dimorphic fungi
44
Paracoccidioidomycosis - clnical disease
- Most infections are asymptomatic.
- Pulmonary infection is similar to histoplasmosis and blastomycosis.
- Disseminated disease presents as chronic cutaneous and mucocutaneous ulcers
45
Paracoccidioidomycosis - diagnosis
- direct observation, cultivation, and serology
| - Have "SHIPS WHEEL" or "MICKEY MOUSE EARS" look.
46
COCCIDIOIDOMYCOSIS where is it found and what usually make this fungus an issue?
-western hemishphere; San Joaquin Valley of Cali and Southern AZ
-drought-rain-drought pattern
large numbers of fungal elements present in blowing dust
47
COCCIDIOIDOMYCOSIS what type of fungus?
- dimorphic fungus
| - arthroconidia are easily airborne
48
COCCIDIOIDOMYCOSIS-primary manifestation in body and the environment
- Following inhalation the fungus converts into a spherule
- multinucleated structure
- produces hundreds of single nucleated spores
- In the environment, spores convert to the mold form; in tissues, they develop into new spherules
49
COCCIDIOIDOMYCOSIS Clinical syndromes
- 60% of infected individuals are asymptomatic
- Pulmonary disease: Mild to moderate influenza like syndrome
- fever, cough, night sweats, malaise and chest pain
- Symptoms develop 1 to 3 weeks after infection
- Most individuals spontaneously resolve the infection in 2 to 3 weeks
- Progressive chronic pulmonary disease which may result in cavity formation and take years to resolve.
50
COCCIDIOIDOMYCOSIS Disseminated disease
- Rare
- Typically develops within one year of infection
- Infection of bones, joints, skin, and central nervous system
51
COCCIDIOIDOMYCOSIS - Coccidial meningitis
develops slowly with increasing headache, fever, stiff neck, and other neurological signs. If untreated, the disease is frequently fatal
52
COCCIDIOIDOMYCOSIS - diagnosis
- Direct observation-distinct **spherule** forms in sputum or biopsy
- Cultivation
- Serology
53
COCCIDIOIDOMYCOSIS - treatment
- Azole
| - Amphotericin B-meningitis and disseminated disease
54
Cryptococcosis where is it found and in what environment?
-all over world
-Can be isolated from the environment
abundant in soil contaminated with bird (mostly pigeon) droppings.
55
what disease is the leading form of fungal meningitis?
Cryptococcal meningitis
56
what kind of fungi is Cryptococcus neoformans?
Encapsulated yeast - NOT DIMORPHIC
57
Cryptococcosis - Pulmonary disease
- asymptomatic or a mild, spontaneously resolving, influenza like illness
- little sputum production
- little damage to the lung (granuloma or cavitation)
58
Cryptococcosis - Disseminated disease
RARE - Skin and bone lesions
59
Cryptococcosis meningitis - presentation of illness
- is the most common recognized form of cryptococcal infection
- develops slowly
- intermittent bouts of headache, irritability, dizziness, and other CNS findings
- Symptoms may present over weeks or months
- AIDS / immunosuppressed =Acute onset
60
Cryptococcosis - diagnosis
- India Ink stain can reveal encapsulated yeast in spinal fluid, aspirates from skin lesions, sputum, and other clinical material :positive approximately 50% of the time
- Cultivation
- Serology
61
Cryptococcosis meningitis- treatment
- Long term treatment (6-10 weeks) with a combination of Amphotericin B and 5-fluorcytosine or fluconazole.
- Relapse in AIDS patients is common and may require suppressive therapy.
62
Blastomycosis histopathology
-broad based budding yeast
63
coccidioidomycosis histopathology
-spherules containing endospores
64
histoplasmosis capsulatum histopathology
intracellular budding yeast
65
paracoccidioidomycoses histopathology
large multiply bidding yeasts
66
Blastomycosis etiology, ecology, clinical manifestation
- blastomyces dermatitidis
- decaying organic material
- Pulmonary disease, extrapulmonary: skin, bone, genitourinrary, central nervous, disseminated diease in immunodef
67
coccidioidomycosis etiology, ecology, clinical manifestation
- coccidiodes immitis and coccidiodes posadasii
- soil and dust
- asymptomatic pulmonary infection in normal host, progressive pulmonary infection and dissemination (skin bone joints, meninges) in immunodef
68
histoplasmosis capsulatum -etiology, ecology, clinical manifestation
- Histoplasma capsulatum
- soil with high nitrogen content (Bird/Bat poop)
- asymptomatic pulmonary infection in normal host and low intensity exposure, disseminated disease in immunodef and children
69
paracoccidioidomycoses - etiology, ecology, clinical manifestation
- paracoccidiodes brasiliensis
- likely soil associated
- self limited pulmonary infection and dissemination (skin, mucosa, bones, lymph nodes, viscera, meninges), more common in children and immunodef patients
70
Pneumocystis jiroveci (carinii) PNEUMONIA (PCP) what is it, who it affects most...
- Highly lethal form of pneumonia
- Occurring primarily in the immuno-compromised
- Single celled eukaryotic organism
- Phylogenetically related to fungi
- Some cellular and metabolic processes similar to protozoa
- The organism is thought to exist in nature and in animals
- kind of like a fungus and kind of like a protozoa
71
Can PCP be grown in lab
NO
72
PCP - clinical syndrome:
- Infection initiated through inhalation of cysts
- Asymptomatic infection in healthy individuals
- Symptomatic: dyspnea, nonproductive cough, and fever
- Patient develops interstitial pneumonitis with cellular infiltrate
- weakness, tachypnea (labored breathing), and cyanosis
- Death results from asphyxiation
73
PCP - diagnosis
- Identification of organisms (trophozoite, sporozoites, cysts) in clinical material
- biopsy, aspiration, or bronchial washing
- Requires specialized staining techniques - silver stain
74
PCP - Treatment
- trimethoprim-sulfamethoxazole: interfere with the folate synthesis pathway of the organism
- Prophylaxis and suppressive therapy is commonly administered in AIDS patients.
75
Aspergillosis affects who, how, and founds where?
- in nature
- immunocomp people - pulmonary to disseminated disease
- Infection through inhalation of conidia --> Hyphal growth in tissue causes pathology
76
Aspergillosis is waht kind of fungus?
A MOLD. ALWAYS A MOLD. (NOT DIMORPHIC)
77
types of Aspergillosis
A. fumigatus and A. flavus
78
Acute Pulmonary Infection caused by and what is it?
- Aspergillomas or “fungus balls”
- Colonization of pre-existing lung lesions: ex) tuberculosis, chronic bronchitis, and other pulmonary diseases associated with cavitary lung lesions
- Consist of hyphae within a matrix of fibrin and cellular debris.
- Typically are unilateral
- Frequently asymptomatic
- infection noted incidentally on X-ray
- Space-occupying lesions that move as the patient changes position.
- Hyphal penetration of blood vessels results in hemoptysis.
79
Invasive/Disseminated/Systemic Infection of Aspergillosis
- Occurs primarily in patients with leukemia, neutropenia, or organ/marrow transplant recipients
- Frequently fatal if not detected
- Invasion of the lung parenchyma following infection : fever, hemoptysis, and chest pain
- Fungal hyphae invade the lumen and walls of blood vessels, causing thrombosis (blood clots), infarction (organ/tissue death), and hemorrhage
- Dissemination from the lung to gastrointestinal tract, brain, liver, and kidney
80
Aspergillosis- Diagnosis
- observation of hyphal elements in sputum or biopsy material
- Culture confirmation.
```
-In tissue section
Septate hyphae (frequently in blood vessels) with V-shaped branches at a ~45degree angle
```
81
which organism has V-shaped branches at 45 degree angles?
Aspergillosis
82
Aspergillosis - treatment
Azole (newer – voriconazole)
Echinocandin
Amphotericin B
Surgical removal of Aspergillomas
83
- 20 yr old male
- fever cough, swollen lymph nodes
- explored cave with bat poop
- x-ray looks like TB but TB test neg
- sputum=mycelial growth at RT
- abundant tuberculate macroconidia on visualization
-histoplasmosis
84
previously healthy, middle aged construction worker
- respiratory symptoms
- sputum = no bacterial growth
- not responding to antibacterials
- pt died- autopsy= granulomatous and suppurative lesions of lung obtained during necropsy = large budding yeast cells - broad base connections
-blastomycosis
