CNS Infections - Kozel Flashcards
Glucose concentrations in the CSF are what percent of the serum level?
60%
What are some specific tests you can order based on clinical suspicion?
Nucleic acid amplification Stain and culture for AFB VDRL test India ink negative stain Cryptococcal polysaccharide antigen Fungal culture Viral culture
What are the following CSF findings for viral infections? WBC count WBC cell type Glucose Protein
WBC: 50-1000
Mononuclear
Glucose >45
Protein <200
What are the following CSF findings for bacterial infections? WBC count WBC cell type Glucose Protein
WBC: 1000-5000
Neutrophilic
Glucose <40
Protein 100-500
What are the following CSF findings for tuberculous infections? WBC count WBC cell type Glucose Protein
WBC: 50-300
Mononuclear
Glucose <45
Protein 50-300
What are the following CSF findings for cryptococcal infections? WBC count WBC cell type Glucose Protein
WBC: 20-500
Mononuclear
Glucose 45
Basically what is the only type of CNS infection that will raise glucose above 45?
viral
What is the only type of CNS infection that will have a neutrophilic infiltrate?
bacterial
What is the normal range of glucose in the CSF?
50-80
What is the normal WBC count in the CSF
0-5
what is the effect of blood in the CSF on the WBC count?
need to adjust the count
What are the reasons for decrased glucose in the CSF?
- Increased glycolysis by leukocytes and bacteria
- Increased metabolic rate of brain and spinal cord
- Altered glucose transport between blood and CSF
What are the reasons for increased protein in the CSF?
disruption of BBB; must also be adjusted if there is blood in the CSF
what are the contraindications for LP?
papilledema; increased ICP
neurological suggestion of intracranial mass
What are the three things you need to do in the initial management of acute meningitis?
- Lumbar puncture and CSF analysis
- Empiric antimicrobial therapy based on patient age
- Adjunctive dexamethasone if appropriate
What is the most common cause of viral meningitis?
enterovirus
What is the most common cause of bacterial meningitis?
Strep pneumo
What are the two causes of spirchetal meningitis
Treponema pallidum
Borrelia burgdorferii
T/F: you can get helminths in the brain
true
what is the invasion process of bacterial meningitis?
Mucosal/nasopharyngeal colonization
Local invasion
Intravascular survival
Meningeal invasion – Moxon experiment
Induction of subarachnoid space inflammation
Alterations of blood-brain barrier
Cerebral edema and increased intracranial pressure
what are the three types of cerebral edema?
- vasogenic from increased BBB permeability
- cytotoxic from swelling of cellular elements of the brain
- interstitial from obstruction of normal flow of CSF
what are the common bacterial pathogens for meningitis of the neonate?
Strep agalactiae
E. coli
Listeria monocytogenes
Klebsiella spp.
What are the common bacterial pathogens for meningitis of the 1-23 month old?
S. agalactiae E. coli H. flu Strep pneumo N. meningitidis
What are the common bacterial pathogens for meningitis of the 2-50 year old?
S. pneumo
N. meningitidis
What are the common bacterial pathogens for meningitis of the >50 year old?
S. pneumo
N. meningitidis
Listeria monocytogenes
Aerobic gram-negative bacilli
What allows disruption of the BBB that allows Abx to reach the brain?
inflammation
what effect do corticosteroids have on abx penetration of the brain?
they reduce inflamm so they also reduce abx penetration of the bbb
What are the features of abx with good CNS penetration in the absence of meningeal inflammation?
- Low molecular weight
- Low degree of ionization at 3. physiological pH
- High lipid solubility
- Low degree of protein binding
- Absence of active efflux systems
What is the Tx for meningitis in the 1 month old?
ampicillin plus ceftoxamine
or
ampicillin plus an aminoglycoside
What is the Tx for meningitis in the 1-23 month old?
Vancomycin plus a third gen cephalosporin
What is the Tx for meningitis in the 2-50 year old?
Vancomycin plus a third gen cephalosporin
What is the Tx for meningitis in the >50 year old?
vancomycin plus ampicillin plus third gen cephalosporin
What is the recommended drug for strep pneumo meningitis?
vancomycin plus third gen cephalosporin
What is the alternative tx for strep pneumo?
Meropenem
Fluoroquinolone
What is the tx for N. meningitidis?
Third gen cephalosporin
what is the alt. tx for N. meningitidis?
PCN G
Ampicillin
fluoroquinolone
What is the tx for listeria monocytogenes?
ampicillin
PCN G
What is the alt. tx for listeria monocytogenes?
TMP-SMX
Meropenem
What is the tx for strep. agalactiae?
Ampicillin
PCN G
What is the alternative tx for strep agalactiae?
third gen cephalosporin
What is the tx for h flu?
third gen cephalosporin
what is the alt. tx for h flu?
cefepime
meropenem
fluoroquinolone
What is the tx for E. coli?
third gen cephalosporin
what is the alt. tx for E. coli?
Cefepime meropenem aztreonam fluoroquinolone TMP-SMX
what are the two things that define chronic meningitis?
indolent onset of greater than four weeks
signs of chronic inflamm in CSF
What are the early symptoms of chronic meningitis?
HA
nausea
decreased memory and comprehension
What are the differences you see in chronic meningitis vs. acute?
onset is more gradual
fever is lower
assc’d with lethargy and disability
pt is often immunocompromised
What are the mycoses that can cause chronic meningitis?
Cryptococcosis
Coccidioidomycosis
Histoplasmosis
Candidiasis
what are the bacteria that can cause chronic meningitis?
Mycobacterium tuberculosis
Treponema pallidum
Borrelia burgdorferii
what are the parasites that can cause chronic meningitis?
Acanthamebiasis
Cysticerosis
Angiostrngylus cantonensis
what are the two defining features of encephalitis?
inflamm in the brain parenchyma
clinical or lab evidence of neuro dysfunction
What are the symptoms of encephalitis?
fever and HA
altered mental status–EARLIER than meningitis
Describe the CSF profile in enceph?
normal glucose
elevated protein
Lymphocytic pleocytosis (elevated lymphs)–magnitude changes with etiology
What are the most common viral etiologies of enceph?
HSV-1 and HSV-2 Varicella-Zoster virus CMV HHV-6 Arboviruses HIV enterovirus ---polio rabies virus
(Vira/bacterial) sources are most common for enceph
viral
What are the possible bacterial causes of enceph?
Listeria monocytogenes Rickettsia spp. Ehrlichia spp. Bartonella spp. Mycoplasma pneumoniae
Is the capsule of a brain abscess well or poorly vascularized?
well vascularized
What are the three sources of a brain abscess?
- Contiguous spread from sinusitis, otitis media, or mastoiditis
- hematogenous spread
- trauma
What are the symptoms of a brain abscess?
HA, N/V, FOCAL NUERO FINDINGS BASED ON SIDE OF ABSCESS
Are brain abscesses singular or mixed in their etiology?
MIxed
What are the two most common sources of brain abscesses?
Strep spp. 70%
Staph aureus 10-20%
What are the most common fungal brain abscesses?
Aspergillus Candida Cryptococcus Mucorales Coccidioides
What is the most common protozoal/helminthic brain abscess?
toxoplasma gondii
Neurocysticercosis is caused by the larval form of (blank)
Taenia solium
What are some other notable causes of helminthic brain abscesses?
Trypanosoma cruzi, Entamoeba histolytica, Shistosoma spp.
What are isolates from a brain abscess caused by sinus and dental infection?
Aerobic and aneorbic streptococci Bacteroides Prevotella spp. Enterobacterieriae Staph aurues
What are isolates from a brain abscess caused by penetrating trauma?
Staph aureus
Aerobic streptococci
Enterobacteriae
Clostridium
What are isolates from a brain abscess caused by pulmonary infection?
Fusobacterium Actinomyces Bacterioides Prevotella Nocardia Streptococci
What are isolates from a brain abscess caused by congenital heart disease?
Streptococci
Staph aureus
What are isolates from a brain abscess caused by HIV infection?
TOXOPLASMA GONDII Nocardia Mycobacterium Listeria monocytogenes Cryptococcus neoformans
What are isolates from a brain abscess caused by transplantation?
Aspergillus Candida Mucorales Nocardia Toxoplasma Gondii
What are isolates from a brain abscess caused by neutropenia?
Aerobic gram-neg bacilli
Aspergillus
Candida
Mucorales
Which bug is this? Gram negative cocci Fastidious pathogen; A) grows on blood, chocolate, and Thayer-Martin Medium B) can only culture on Thayer-Martin
Neisseria
Neisseria produces (blank) oxidase which can be used to ID it
indphenol oxidase
T/F: Neisseria is easily killed by sunlight, heat, and chemicals
true
Neisseria has a (blank)-specific CPS
group specific
Which group of neisseria is the epidemic strain?
group A
Groups B, C, Y, and W-135 are which type of Neisseria strains?
endemic
Which group of Neisseria is a polymer of sialic acid?
Group B
Group B Neisseria is (poorly/stronlgy) immunogenic
poorly; seen as self
Group B Neisseria ag is expressed in what specific tissue?
neonatal!
Which group of the endemic Neisseria strains can occasionally become epidemic?
group C
Neisseria has (group/type) specific outer membrane protiens and lipooligosacchardies
type specific
T/F: Meningococcemia can occur with or without meningitis
true
What are the general findings in a meningococcal infection?
Meningococcemia
Meningitis
Petechial lesions
Petechiae correlate with the degree of (blank) due to DIC
thrombocytopenia
T/F: patients with fulminant sepsis and meningitis show purpura, petechia, and echymoses
true
what part of neiserria makes it antiphagocytic?
the capsule
What part of neiserria is extremely toxic and produces inflamm?
LOS
LOS contains lipid (A/C) and the core oligosaccharaide
lipid A
T/F: LOS has the O antigen
false; lacks the O ag
How is LOS released from neisseria?
from the bacterial surface as the membrane blebs
Neisseria has (pili/flagella)
pili
Neiserria first gains access to the body where?
nasopharynx
Neiserria uses its (blank) to adhere to the epi cells of the nasopharynx
pili
besides prevent phagocytosis, what else does the capsule of neiserria do?
prevents complement mediated lysis
Which part of Neisseria causes tissue damage?
LOS
DIC from Neisseria is caused by what toxic part of the bacteria?
LOS
Multiple attacks of Neisseria is associated with depletion of which complement factors?
C5,6,7,8
What types of specimens do you need to collect to Dx Neisseria?
blood
CSF
NP secretions in the carriers
How do you visualize Neisseria?
Direct exam with gram stain of the CSF
What type of culture and special conditions are needed to culture Neisseria?
Culture IMMEDIATELY
incubate in CO2
Use Thayer-martin agar
What is the gram stain and general appearance of Neisseria?
gram negative diplococci
What is the oxidase status of Neisseria?
oxidase positive
Neisseria oxidatively produces acid from what?
sugars, eg glucose and maltose
How is Neisseria spread man to man?
airborne transmission via respiratory droplets
Which populations are most susceptible to Neisseria?
young kids (no Abs) college students and military recruits (crowding and fatigue)
What is the carrier rate of Neisseria?
1-40%; few carriers develop disease
T/F: Neisseria only happens in outbreaks
false; may occur sporadically or in epidemics, hence the multiple strains
immunity to meningococcus is due to what?
anticapsular AB
what are the MOA’s of immunity to Neisseria?
complement mediated lysis and opsonization
Anticapsular Ab is the major factor that determines (blank vs. blank)
resistance vs. susceptibility
What explains the risk of Neisseria in kids between 6-24 months?
lack of anticapsular Ab
Naturally ocurring Abs to Neisseria are probably due to the carrier state and to cross reacting with what other bacteria?
E. coli
The tetravalent meninogcoccal vaccine has which four Neisseria strains?
A
C
Y
W-135
What part of the bacteria does the meningococcal vaccine contain?
purified polysaccharide only
T/F: The tetravalent vaccine is one of two vaccines used for adults older than 56
false; the only one
The (polysacc/polysacc-protein) vaccine is used to vaccinate adolescents against meningitis
polysacc-protein conjugate
Which four strains does the polysacc-protein conjugate vaccine against meningitis have?
A
C
Y
W-135
When do kids get the meningitis vaccine?
11-12
when do you get a meningitis booster?
16-18
What are the special populations that should receive the meningococcal vaccine besides adolescents?
College freshmen living in dormitories Microbiologists with potential exposure Military recruits Travelers to endemic regions Terminal complement deficiencies Anatomic or functional asplenia
Why is group B neisseria not included in any vaccine?
poorly immunogenic
The vaccine for group B neisseria targets (blank)
factor H protein
what is the vaccine for cholera?
inactivated v. cholera
what is the vaccine for diphtheria?
toxoid
what is the vaccine for h. flu?
CPS-protein conjugate
What is the vaccine for meningococcus?
Multivalent CPS or CPS-protein conjugate
What is the vaccine for pertussis?
Inactivated or disrupted B. pertussis
Acellular vaccine of purified proteins
What is the vaccine for pneumococcus?
Multivalent CPS or 13-valent CPS-protein conjugate
What is the vaccine for tetanus?
toxoid
What is the vaccine for TB?
live attenuated BCG
what is the vaccine for typhoid?
heat killed S. typhi
live attenuated oral vaccine
What is the std. Tx. if N. meningitidis is ID’d?
1. Third gen cephalosporin or PCN G or Ampicillin 2. extensive supportive care 3. chemoprophylaxis for family contacts using rifampin
Why is a third gen cephalosporin or PCN G/Amp used to Tx N. meningitidis?
readily penetrates inflamed meninges
what are some of the clinical signs of H flu in the newborn?
fever
refusal to eat
grunting respirations
hypertonicity
what causes Brazilian purpuric fever?
H. flu biogropu aegyptius
What causes acute purulent conjunctivitis?
H. aegyptius
What causes soft chancre veneral disease?
H. ducreyi
What is the morphology of H. flu?
very small gram neg. rods
What are the special nutritional requirements of H. flu?
X factor aka hematin
V. factor aka NAD
Chocolate agar
Why must chocolate agar be heated for H. flu?
lyses RBCs to release X and V factors
inactivates inhibitor of V factor
(blank) can causes satelliting on plates of H. flu as it also releases X and V factors
S. aureus
T/F: H. ducreyi also requires X and V factors
false; only needs X factor
WHat part of H. flu prevents phagocytosis?
CPS
how many types of H flu capsule are there?
a-f
WHat type of H flu causes almost all systemic disease>?
H flu B
H flu B secretes what unique chemical?
polyribitol phosphate
T/f; there are many common non-typable strains of H flu that lack a capsule
true
H flu begins where?
as nasopharyngitis
Which strains of H flu most commonly migrate to the sinuses or middle ear? What else can do this?
non-typeable strain
can also be strep pneumo or Moraxella catarrhalis
H flu that extends to the blood and meninges is what type?
B
(blank) strains of H flu cause epiglotitis
encapsulated strains
H flu pneumonia is secondary to (blank) virus infection
influenza
H flu B capsule is able to block (blank) mediated lysis
complement
H flu b is releases what that causes meningeal inflamm?
endotoxin
WHat types of samples do you need to collect to ID Hib?
NP swab, blood, CSF
Gram stain of (blood/CSF) can give a provisional Dx of H flu
VSF
What must be done to culture H flu?
culture immediately; does not survive well
The ID of H flu is made on the need for what nutritional supplements?
X and V factor
Latex agglutination is an assay to detect (blank) in the CSF
H flu B capsular antigen
What percent of pts with H flu meningitis have neuro sequelae?
30-50%
What is URT carrier rate of H. flu in kids?
30-50%
most carrier strains of H flu are (typeable/non-typeable)
non-typeable causing otitis media
There are (many/few) asymptomatic carriers of H flu B
few
What is the primary risk factor for H flu meningitis?
lack of anticapsular Ab
What is the MOA of protection of the anticapsular Ab to H flu?
opsonization and complement mediated lysis
H flu meningitis is most common in what age group?
6 months and 3 years
Maternal Abs protect against H flu until what age?
6 months
Exposure to Hib carriers and cross reactive ags protect kids until what age?
3
What was in the old vaccine for Hib?
polyribitol phosphate aka the CPS
What was the issue with the old vaccine?
poorly immunogenic in kids younger than 18 months
What is in the current vaccine for H flu?
protein conjugate;
What is in the connaught vaccine for H flu?
PRP coupled to diptheria toxoid
what is in the Praxis Biologics vaccine for H flu?
PRP coupled to nontoxic mutant of diphtheria toxin
What is in the Merck, Sharp, and Dohme vaccines for H flu?
PRP coupled to the N meningitidis OMP
When is the H flu vaccine given?
2 months
T/F: the vaccine for Hib reduces the carrier rate
true; goal is elimination of Hib
Should you wait for pos cultures before treating for H flu?
NO; NEEDS IMMEDIATE TX
What is the firstline Tx for H flu?
broad spectrum cephalosporin with CNS penetration; aka cefotaxime or ceftriaxone
What is used to cleanse carriers of H flu?
rifampin
What causes this?
Following conjunctivitis– Acute onset of fever, vomiting and abdominal pain, followed by purpura, vascular collapse and death
Brazilian purpuric fever
aka
H flu biogroup aegyptius
Where is H. ducreyi common?
Afrika
What is a probable co-factor in transmission of AIDS in Afrika?
H. ducreyi
What is the morphology of Strep pneumo?
Gram pos
ovoid or lancet shaped in pairs
aerobic
Is strep pneumo neked or encapsulated?
ENCAPSULATED
Older cultures of strep pneumo undergo (blank), which is activated by surfactants such as bile and detergents
autolysis
Strep pneumo can undergo a rough-to-smooth conversion via…..
transformation
what agar must be used to grow strep pneumo?
blood agar
What is the major ag in strep pneumo?
CPS
the CPS of strep pneumo is (T/B) independent
T independent
incubation of encapsulated bacteria with antibody makes the capsule refractile is known as the (blank) reaction
Quellung
Strep pneumo C polysaccharaide is aka….
teichoic acid
teichoic acid is a cell wall CHO that reacts with which acute phase protein?
CRP
strep pneumo pneumonia is (lobar/hilar) in 80-90% of cases
lobar
Strep pneumo is the most common cause of (blank() in children older than three months
otitis media
Strep pneumo is the most common cause of (blank) among the young and the elderly
meningitis
What are some other complications of a strep pneumo infection?
peritonitis, endocarditis, arthritis
What are the characteristics of meningitis from strep pneumo?
by abrupt onset, toxicity, fulminant course and DIC
What is the actual dz state due to with infx of strep pneumo?
inflammatory response to both the bacteria and its products
T/F: the CPS of strep pneumo is essential for its virulence
true
What part of strep pneumo is antiphagocytic?
the CPS
What type of Ab protects against strep pneumo via opsonization only?
anticapsular ab
What does the the anticapsular Ab against N. meningitidis and Hib do that the one for strep pneumo can’t?
activate complement mediated lysis
(blank) is a porin similar to Streptolysin O found in strep pneumo
Pneumolysin
What is the effect of pneumolysin?
contributes to inflammation
PDG and lipoteichoic acid are components of the….
cell wall
PDG and lipoteichoic acid activate the (classical/alternative) complement pathway
alternative
PDG and lipoteichoic acid elicit which two cytokines?
IL1
TNFa
What two components of strep pneumo are largely responsible for the inflammatory response?
PDG
lipoteichoic acid
t/F: natural resistance to strep pneumo is very high
true; 40-70% of people carry strep pneumo in the NP
WHat are the natural defensive barriers against strep pneumo?
Cough and epiglottal reflex
Mucus and cilia
Phagocytosis by alveolar macrophages
Splenic clearance from blood
What are some of the conditions that lower resistance to strep pneumo?
depressed action of cilia depressed epiglottal reflex hyposplenia or asplenia SICKLE CELL DISEASE malnutrition
What are some causes of depressed epiglottal reflex?
EtOH, morphine, anesthesia
What are some causes of depressed action of cilia?
viral infx aka flu
What are the characteristics of pneumococcal pneumonia?
- sudden onset with shaking chill, fever, and sharp pleural pain
What does the sputum look like in pneumococcal pneumonia?
bloody and rusty
Where in the lungs does pneumococcal pneumonia localize in the lung?
lower lobes
What types of samples do you need to Dx pneumococcal meningitis?
sputum and body fluids:
CSF
pus
etc
What two things must you do to do a direct examination of strep pneumo?
gram stain
DNA PROBE
what type of agar do you need to use to isolate strep pneumo?
blood agar
What are the three things that differentiates strep pneumo from strep viridans?
alpha hemolytic
Optochin sensitive
Bile soluble
What types of serologic tests can you do to test for strep pneumo?
free ag in body fluids
pneumococcal C polysacc
T/F: most infections with strep pneumo are endogenous
true
Despite most infections with strep pneumo being endogenous, most healthy adults lack the (blank), unlike N. meningitidis and Hib
anticapsular ab
What are the steps to prevent and control strep pneumo infx?
prevent primary damage
immunization as needed
isolation to prevent transmission to pts at risk
Strep pneumo enters and exits the body via the…
URT
What do both of the pneumonia vaccines contain?
purified capsular polysacc
The pneumonia vaccine is (poly/monovalent)
polyvalent
What is the MOA of the pneumo vaccine?
induction of opsonic Ab
What is the efficacy of the pneumo vaccine?
60-80%
The titers for the pneumo-vax last for how long?
5 years
The Ag involved in the pneumo vax is (T/B) independent and therefore not suitable in kids younger than two
T independent
What are the populations that should be vaccinated with pnuemovax?
all adults older than 65 or in series with PCV 13
anyone 6-18 with specific risk factors
What is different about the polysacc-protein conjugate pneumo vax?
also covers 65% of acute otitis media in kids younger than six
also T independent
Reccomended for ALL children
Reduces carriage and produces herd immunity
What is the firstline Tx for strep pneumo?
PCN or ceftriaxone IF SUSCEPTIBLE; increasing reports of resistance
Strep pneumo resistance means that the lab needs to do more (blank) to determine the right abx
sensitivity testing
What is the MOA of strep pneumo resistance?
acquisition of a PBP with reduced affinity for abx
What are the alt. abx used for strep pneumo?
vancomycin
macrolides
doxycycline
quinolone
What is the empiric treatment for pneumococcal meningitis?
ceftriaxone or PCN + vancomycin
What is the reason to use ceftriaxone for pneumo meningitis?
better CNS penetration
Why do we include vancomycin in the Tx for pneumo meningitis?
coverage if resistant to B lactam
PCN (does/does not) pass through the normal BBB
does not
What is the ironic part of giving PCN to treat pneumo meningitis?
kills bacteria, which releases more PDG and TA, resulting in more inflamm, which causes increased ICP and IRREVERSIBLE BRAIN DAMAGE
How can you reduced the inflamm when giving abx for pneumo meningitis?
corticosteroids
GBS is part of the normal flora of….
GI and GU tracts
What is the leading cause of neonatal sepsis and meningitis?
GBS
what are the risk factors in adults that lead to systemic GBS?
diabetes
cancer
HIV infx
What is the key virulence factor in GBS?
antiphagocytic capsular polysaccharide
t/F: the Ab to the CPS of GBS is protective even in the newborn
true
When does GBS onset in the newborn
within the first week
How is GBS in the newborn acquired?
in utero or during birth
What are the symptoms of infx with GBS in the newborn?
bacteremia
pneumonia
and/or meningitis
When does late onset neonatal infections happen?
1 week to 3 months
How is late onset neonatal infections acquired?
from mother or another infant
WHat are the symptoms of late onset neonatal infection?
bacteremia and meningitis
How does GBS infx present in older adults>?
bacteremia, pneumonia, bone/joint infection and skin and soft tissue infection
WHat are the risk factors for early onset neonatal disease?
- Exposure to bacterium via mother carrier, prolonged membrane rupture, or intrapartum fever
- Absence of anticapsular Ab from mom lacking it or delivery sooner than 37 weeks
How do you ID GBS in the lab?
Gram stain
BETA hemolytic
Agglutination test for Lancefield Group B AG
What are the methods of preventing early onset neonatal disease?
- unverisal screening of all preg women at weeks 35-37 for rectal/vaginal colonization of GBS
- intrapartum abx prophylaxis
When do you give intrapartum abx prophylaxis?
- at time of labor when membrane ruptures
- all preg women who test pos for GBS
- Give PCN G or Ampicillin
Is there a vaccine to prevent early onsent neonatal disease?
nope
What is the empiric treatment of early onset neonatal disease?
Ampicillin plus aminoglycoside
What is the specific Tx for ID’d GBS neonatal disease?
PCN G
What are the indications for intrapartum GBS abx prophylaxis?
- previous bebe with GBS dz
- GBS bacteriuria during current pregnancy
- Positive GBS screen
- GBS status unknown plus any:
a) delivery before 37 weeks
b) amniotic membrane rupture greater than 18 hours
c) intrapartum temp >100.4
Cryptococcus neoformans is a (naked/encapsulated) yeast
encapsulated
What is the foundation of Dx of cryptococcus?
Assay for CrAg (cryptococcal ag)
How many serotypes of cryptococcus are there?
four: A-D
WHat species are serotypes A and D?
C. neoformans
What species aer serotypes B and C of cryptococcus?
C. gatti
Globally, what is the most serious and life threatening of the pathogenic fungi?
Cryptococcus
Where is cryptococcus found?
Saprophyte found in pigeon droppings and associated with EUCALYPTUS TREES
Which species of cryptococcus is associated with eucalyptus trees?
C. gatti
T/F: Cryptococcus is likely present in all people
true; causes a subclinical infection that goes latent
Why does cryptococcus reactivate in HIV/AIDS?
drop in T cell function
Where do we see most cases of cryptococcus acutely?
Sub-Saharan Africka; think AIDS
Cryptococcal infections in AIDS is well controlled with the use of ….
HAART
Pulmonary cryptococcosis begins as what type of infx?
pulmonary, duh
Which strain is most commonly the cause of pulmonary cryptococcus?
C. gatti
Cryptococcal meningitis is highly neuro(blank)
neurotropic
What are the other manifestations of a cryptococcal infx?
Skin lesions
Ocular infection
Prostatic involvement – possible asymptomatic reservoir
Since cryptococcus is opportunistic, in what situations do we see active infx?
HIV/AIDs
immunosuppresion aka organ transplant
What strain of cryptococcus do we see in NON-HIV and NON-transplant hosts?
C. gatti
What types of specimens do you need to collect in order to Dx cryptococcus?
Blood/serum AND CSF
What types of stains do you need to do to visualize cryptococcus?
india ink looking for an encapsulated yeast
Ag detection of cryptococcus can happen via what three fluids?
serum
plasma
CSF
What are the three methods of assaying for CrAg?
latex agglutination
enzyme immunoassay
LFI
What i the lowest reliability Dx for cryptococcus?
india ink stain in NON-AIDS pts; only 50% sensitivity
T/F: cryptococcal tx can be mono or combo
true
What are the antifungals you would use against cryptococcus?
Amphotericin B
Flucytosine
Fluconazole
T/F: Tx of cryptooccus is different for immunocompromised pts
true
What are the three phases of Tx of cryptococcus?
Induction
Consolidation
Maintenance
What is Immune reconstitution inflammatory syndrome (IRIS)?
Occurs at initiation of HAART
Overwhelming inflammatory response to previously acquired OI
In symptomatic pts, how do you initially Dx cryptococcal infection?
CSF, or if access to LP limited, THEN do serum CrAg
USE THE LFI
What drugs should be used in the induction phase of crypto tx?
Amphotericin B
Flucytosine
Fluconazole
TOGETHER
What drugs should be used in the consolidation phase of crypto tx?
Fluconazole
What drugs should be used in the maintenance phase of crypto tx?
Fluconazole
WHen should all AIDS pts be screened for CrAg?
prior to starting ART
T/F: all CrAg pos pts should be treated BEFORE starting ART
true