Fungal infections Flashcards
1
Q
6 reasons why fungal infections are on the rise
A
solid organ transplant high doses of chemotherapy indwelling catheters broad spec ABX surgical and ICU patients Immunocompromised
2
Q
what three types of patients have fungal infections as a major cause of death?
A
cancer, transplant and AIDS patients
3
Q
what species accounts for 78% of all nosocomial fungal infections?
A
Candida
4
Q
how are most fungal infections acquired?
A
accidental inhalation
5
Q
what are some lab tests for fungal infections? (4)
A
fungal culture (SLOW growth) PCR, western blot (more rapid ID), KOH
6
Q
Endemic infection:
A
disease causing fungi to normal healthy & immunosuppressed individuals in a specific geographic region
7
Q
opportunistic infection:
A
cause invasive infections in only severely immunosupressed pts
8
Q
types of endemic fungi:
A
histoplasmosis, blastomycosis, coccidiomycosis
9
Q
types of opportunistic fungi:
A
cryptococcis, aspergillus, candida
10
Q
where is Histoplasma capsulatum found?
A
in soil that is contaminated with bird or bat droppings (central/eastern US)
-moist environments
11
Q
how is Histoplasma capsulatum transmitted?
A
inhalation of spores; small budding cells are engulfed by phagocytes in the lungs and carried to other tissues
12
Q
signs and sx of a mild histoplasmosis infection
A
- depends on immune sys of host
- asymptomatic or mild
- mild flu (1-4 days)
13
Q
S/SX for a moderate/severe histoplasmosis infection (4)
A
atypical pneumonia
fever
cough
central chest pain (5-15 days)
14
Q
acute histoplasmosis (sx, duration, prognosis)
A
- prostration, fever, few pulm complaints
- 1 week-6 mo
- almost never fatal
15
Q
chronic progressive pulmonary histoplasmosis is MC seen in which pts?
A
usually seen with older pts w/ COPD (impaired cillia, can’t clear infection)
16
Q
disseminated histoplasmosis happens in which patients?
A
severely immunocomramised (primary infection or re-occurrence)
17
Q
6 need to knows about disseminated histoplasmosis
A
- Often reactivation of prior infection
- Commonly seen in patients with HIV
- CD4 count
18
Q
8 lab findings for histoplasmosis
A
- CBC= anemia
- sputum= + in chronic dz 12wk growth
- blood culture
- antibody testing (cross reacts with other fungi)
- MRI/CT (CNS histo)
- urine assay (90% sen for dissem dz in HIV pts)
- CXR
- skin test (high rate in endemic areas, not recomm.)
19
Q
CXR findings of histoplasmosis
A
calcification, diffuse pneumonia, miliary pattern
20
Q
general tx for histoplasmosis
A
-none for actue
-mild/moderate:
itraconazole 200-400mgQD/2-3 months
21
Q
tx for histoplasmosis in AIDS pt
A
life long itraconazole 200-400mg/day
22
Q
tx for histoplasmosis in severely ill/immunocomp or pts who have failed itra or oral tx
A
amphotericin B, liposomal (lipid form of ampho B, may be safer for really ill pts)
23
Q
what organism causes blastomycosis?
A
blastomyces dermatitidis
24
Q
where is blastomyces dermatitidis found?
A
nitrogen rich soil of central and southeast US and Canida
25
how does blastomycosis present? (normal, not chronic or disseminated)
asympomatic in mild dz
80% chronic pulm dz
cough, moderate fever, dyspnea, CP
breif flu like illness with rapid resolution
26
how do pts present with chronic blastomycosis infections?
bloody, purulent sputum, pleurisy, chills
| pneumonia like
27
presentation of disseminated blastomycosis
-lesions on skin, bones and urogenital system
-raises, verucous lesions
-epididymitis, prostatitis
-
28
what patients is disseminated dz most commonly seen in?
immunocompromised; if they are not move to HIV/cancer testing
29
lab tests for blastomycosis
CBC: leukocytosis, anemia
Sputum: grows readliy, keep for 4 weeks
serological: not well standarized
30
1st choice tx of blastomycosis
-itraconazole 200-400mg/day/2-3 mo (non meningeal dz)
31
backup tx for blastomycosis
- amphotericin B 0.3-0.6mg/kg/day IV (CNS, tx failure, bad infections)
- ketoconazole (not well tolerated)
32
what do you see on a CXR of blastomcosis
cavitary lesion with fluid/air line, cotton ball infiltrates
33
what organism causes coccidioidomycosis
cocidiodes immitis
34
where is cocidiodes immitis found?
soil of warm, dry region of southwest US, more common in heavily populated areas
35
what is coccidioidomycosis AKA
San Joaquin valley fever or desert rheumatism
36
incubation period of coccidoidomycosis
10-30 days
37
what are the Sx of coccidoidomycosis
60% asymptomatic
-flu like, pnumonia like infection
-myalgia, fatigue, arthralgia
rash/lesions
38
describe the rash/lesions of coccidoidomycosis
nodules with rat eaten boarder (seen in acute dz 2-20 days)
39
what does the CXR show for coccidoidomycodid?
cavitary lesions, abscesses
40
1% of coccidioidomycosis cases become disseminated, how does that present and in which patients?
meningitis (stiff neck, fever, HA)
| HIV, DM
41
how do you Dx coccidioidomycosis?o B
- serologic testing (good for dx and prognosis)
- CSF (inc WBC, red glucose, 30% of the time you see organism)
- blood cultures (rarely positive)
42
tx for coccidioidomycosis
- mild pulm cases: oral azoles
- severe pulm: Ampho B
- Meningitis: fluconazole, ampho B, Voiconazole
- bones/SST: itraconazole
43
cryptococcus: how many species and what's the one found in humans?
20 species
| C. neoformans, also gattii
44
where is cryptococcus found?
in bird feces, fresh fruits, veggies and dairy products
45
where geographically is neoformans found vs gattii?
neoormins: universally
gatti: mostly tropical and subtropical climates
46
what population does neoformans/gattii infect?
neo=immunocompromised (90%)
| gatti= more immunocompetent
47
pulmonary s/sx/prognosis for cryptococcus
- mild and rapid resolution (pneumonia like)
- severe sx usu disseminated dz
- 40% mortatlity in AIDS
48
What is the MOST COMMON manifestation of disseminated cryptococcus?
CNS/meningitis
49
what are 6 Sx of CNS cryptococcus
headache, fever, AMS, memory loss, meningismus, photophobia
50
3 other manifestations of cryptococcus (not pulm or CNS)
skin, skeletal and prostate lesions have been observed
51
how do you Dx cryptococcus infections?
```
-CSF/culture (DO A HEAD CT 1ST)
(inc opening pressure, inc protein, dec sugar)
-CT or MRI
-Cryptococcal capsule antigen
-india ink stain= budding
```
52
what two lab test together have a 90% sensitivity for cryptococcus infections?
CSF findings and CSF culture together
53
prognostic signs associated with poor outcomes with cryptococcus infections?
- altered mental status
- elevated opening pressure on LP
- low CFS leukocyte count
- high CSF and serum cryptococcal antigents
54
tx of cryptococcus infection (include meningitis, severe dz and maintenance
- AIDS/meningitis: oral flucanazole for 10 weeks
- severe dz in AIDS pt: Ampho B X14 days; oral flucanazole life long; flucytosine (prevents reoccurnace)
- maintenance in AIDS pts: fluconazole until CD4>200
55
what is the most commin invasive mold infection in the world?
Aspergillosis
56
what organism causes aspergillosis?
Aspergillus fumigatus (90%)
57
where is Aspergillus fumigatus found?
soil, plants, rotten veg, hot water supply, ground spices
58
what makes Aspergillus fumigatus dangerous in reguards to respiratory system?
they have small spores that when inhaled can penetrate deep into the lungs
59
In what type of patients do you see Aspergillosis? (5)
```
immunocompromised
organ transplant
neutropenic pts
burn victims
DM
```
60
5 pulmonary S/Sx of Aspergillosis
dyspnea, cough, hypoxia, bilateral infiltrates, hemotypsis (w/ normal CBC)
61
S/Sx of tracheobronchitis d/t aspergillosis (3-4)
fever, cough, ranges from mucus production to ulceration
62
S/Sx of sinusitis d/t aspergillosis (4)
fever, sinus pain, sore throat, spreading to orbits/palate
63
S/Sx of disseminated aspergillosis (2-3)
(rare, usually discovered post mortem)
- cutaneous, errythema/red or purple lesions
- mental status changes
64
lab finding of aspergillosis
- cultures, serologic testing
- ELISA (most specf. and sen)
- tissue biopsy
- CT scan
65
what's the most specific and sensitive test for aspergillosis?
ELISA
66
treatment for aspergillosis
voriconazole
Ampho B
Cancidas
67
Candida is a normal flora found in.....
skin, GI, GU, pulmonary
68
what candida species are pathogenic to humans?
* C. albicans (50-70%)
* C. tropicalis
* C. glabrata
* C. parapsilosis
* C. krusei
69
candida infections require what:
breakdown in host's defense
70
where are Candida fungi found?
food, soil, inanimate objects, prevalent in hospital environments, body secretions
71
what are the two major portals of entry for candida?
skin and GI tract
72
who is at risk for a candida infection? (6)
```
neutropenic Pt
cancer pt
renal failure
use of ABX or corticosteroids
prolonged hospitalization
invasive treatments
```
73
what 3 organs are typically involved in invasive/candidemia infections
liver, brain heart
74
S/SX of candidemia of
acute onset of fever, tachycardia, tachypnea
| -deterioration of condition w/ or w/out fever
75
three fun facts about oropharyngeal and esophogeal candidiasis
- oral mucosa=thrush
- c. albicans is primary pathogen
- found in oral flora in 30-60% of adults
76
risk factors for oropharyngeal and esophageal candidiasis (~7)
```
use of steroids and ABX
dentures
disruption of oral mucosa
HIV, neonates, Elderly
Diabetes
malignancy
nutritional deficiencies
```
77
presentation of oropharyngeal candidiasis
-stomatitis (inflamed sore mouth)
-dysphagia
-diffuse erythemia, whit patcheson surface of tongue, bucal mucosa, throat or gums
"cheesy"
78
pt's with oropharyngeal candidiasis will ahve what in their Hx (~3)
- Hx of local defense damage
- mucous MB damage
- Hx of ABX, chemo, trauma, corticosteroid
79
lab studies for oropharyngeal candidiasis (2)
- scrape the lesion- microscopic eval=budding yeast
| - cultures (does not distinguish b/t colonization and true infection)
80
what do you see on endoscopy with esophageal candidiasis?
white, ulcerative patch (with odynophagia)
81
lab studies for esophageal candidiasis? (2)
- GI endoscopy (biopsy confirms dx)
| - cultures- helpful w/ sensitivity/ susecptable drugs
82
tx of esophageal candidiasis?
- nystatin suspension, clotrimazole troches (contact for 20-30 mins, swish)
- systemic: for more severe infections
83
what organism causes 80% of the vulvo-vaginal candidiasis infections?
candida albicans (common vaginal flora)
84
5 risk factors for vulvo-vaginal candidiasis infections?
```
sexual activity
oral contraceptives
ABX use
pregnancy
diabetes
```
85
presentation of vulvo-vaginal candidiasis infections (6)
itching, soreness, irritation, burning with urination, erythema, vaginal DC
86
Dx of vulvo-vaginal candidiasis
- Clinical Dx usually
| - 10% potassium hydroxide microscopy
87
non-pharmacological tx for vulvo-vaginal candidiasis
avoid harsh soaps and perfumes, keep genital area clean and dry, eat lactobacillus containing (probiotic) yogurt
88
pharmacological tx for vulvo-vaginal candidiasis
uncomplicated: topical or oral
*fluconazole (oral)*
(a bunch of "-azole" options, and nystatin)
89
pharmacological tx for complicated vulvo-vaginal candidiasis
same (topcial) drugs increase duration of tx to 10-14 days
| upto date says: 2-3 oral doses of fuconazole every other day
90
how does candidasis become a deep, invasive infection
- cathederization and broad spec ABX can cause candida cystitis
- an also be in blood stream (candidemia/ candiduria)
91
what do you see in blood or urine cultures fo rdeep, invasive candidasis infections?
- leukocytosis, no bands
| - 100,000 organisms/ml in urine is diagnostic w/ fever
92
tx of candiduria
-tx only required if symptomatic
-fluconazole 200mg/d X14d
(Ampho B bladder irrigation BID is minimally effective)
