Unit 15 - CNS Infections Flashcards
(105 cards)
1
Q
What agents cause meningitis?
A
- Neisseria meningitidis
- Haemophilus influenzae
- Streptococcus pneumonia
2
Q
Encephalitis
A
inflammation of the brain
3
Q
Meningitis
A
inflammation of the meninges caused by viral or bacterial infection
4
Q
What can cause encephalitis?
A
- HSV
- Polio
- WNV
5
Q
What does the CNS include?
A
brain, spinal cord, cranial nerves
6
Q
What is the CNS protected by?
A
bone and membrane layers
ex. brain - skull
ex. spinal cord - vertebral column
7
Q
Blood-borne invasion across BBB to cause _____
A
encephalitis
8
Q
Blood-borne invasion across CSF to cause ______
A
meningitis
9
Q
How can microbes cross BBB?
A
1-Growing across, infecting the cells that comprise the barrier
2-Being passively transported across in intracellular vacuoles
3-Being carries across by infected white blood cells
10
Q
Normal:
Cells/mL
A
0-5
11
Q
Normal:
Protein (mg/dL)
A
15-45
12
Q
Normal:
Glucose (mg/dL)
A
45-85
13
Q
Septic (purulent meningits):
Cells/mL
A
200-20,000 (mainly neutrophils)
14
Q
Septic (purulent meningits):
Protein (mg/dL)
A
high (>100)
15
Q
Septic (purulent meningits):
Glucose (mg/dL)
A
<45
16
Q
Septic (purulent meningits):
Causes?
A
bacteria, amoebae, brain abscess
17
Q
Aseptic meningitis or meningoencephalitis:
Cells/mL
A
100-1000 (mainly mononuclear)
18
Q
Aseptic meningitis or meningoencephalitis:
Protein (mg/dL)
A
moderately high (50-100)
19
Q
Aseptic meningitis or meningoencephalitis:
Glucose (mg/dL)
A
Normal
20
Q
Aseptic meningitis or meningoencephalitis:
Causes?
A
viruses, Mtb, fungi, brain abscess, partly treated bacterial meningitis
21
Q
Describe bacterial meningitis
A
- More severe but less common
- Prior to 1990s, Hib most common
- Neisseria meningitidis, Streptococcus pneumoniae are the other two key pathogens
- Life-threatening
22
Q
Neisseria meningitis:
Virulence factors
A
- Capsule
- IgA Protease
- Pili
- Endotoxin
- Outer membrane proteins
23
Q
Haemophilus influenzae:
Virulence factors
A
- Capsule
- IgA Protease
- Pili
- Endotoxin
- Outer membrane proteins
24
Q
Streptococcus pneumoniae:
Virulence factors
A
- Capsule
- IgA Protease
25
Possible causes of bacterial meningitis in Neonates (<1 month)
Gram negative bacilli
- E. coli, Klebsiella, Enterobacter
- Streptococcus agalactiae (group B)
- Listeria monocytogenes
26
Possible causes of bacterial meningitis in Infants (1-23 months)
- Streptococcus agalactiae (group B)
- E. coli
- Haemophilus influenza
- Streptococcus pneumoniae
- Neisseria meningitidis
27
Possible causes of bacterial meningitis in Children (>2 yrs) & Adults
- Streptococcus pneumoniae
| - Neiserria meningitidis
28
Possible causes of bacterial meningitis in Older Adults (>65 yrs)
- Streptococcus pneumoniae
- Neisseria meningitidis
- Listeria monocytogenes
- Aerobic gram-negative bacilli
29
Meningococcal Meningitis:
____% of population is carrier
*Higher carrier rates during epidemics
20
30
Meningococcal Meningitis:
| ___ for attachment to epithelium of nasopharynx
pili
31
Meningococcal Meningitis:
| Invasion of blood and meninges _____
rare
32
Meningococcal Meningitis:
| Presence of Abs to capsular Age protects from _____
invasion
33
Meningococcal Meningitis:
| Individuals with _____ _________ deficiency more susceptible
C5-C9 complement
34
Meningococcal Meningitis:
| Who is at greater risk?
- Young children who have lost maternal Abs
| - Adolescents who never encountered infecting serotype
35
Meningococcal Meningitis:
| _______ infection
droplet
36
Droplet infection
An infection transmitted from one individual to another by droplets of moisture expelled from the upper respiratory tract through sneezing or coughing.
37
Droplet infection is worse during ______ and ________
overcrowding and confinement (prisons, college dorms, military barracks, etc.)
38
Meningococcal Meningitis:
| Peak?
winter/early spring with carrier rates between 60-80%
39
Meningococcal Meningitis:
| Incubation time?
1-3 days
40
Meningococcal Meningitis:
| Causes sudden onset of ??? (symptoms)
- headache
- sore throat
- drowsiness
- fever
- stiff neck
- hemorrhagic skin rash (indicates septicemia)
41
Meningococcal Meningitis:
| Mortality (untreated)
100%
42
Meningococcal Meningitis:
| Mortality (treated)
10-15%
43
Meningococcal Meningitis:
| Is there a vaccine available?
yes
44
Meningococcal Meningitis:
| Which serotypes are in the vaccine?
Serotypes A, C, Y and W135 (routine childhood vaccination)
45
Meningococcal Meningitis:
| There are two vaccines, please describe them
1) Meningococcal polysaccharide vaccine (MPSV4)
| 2) Meningococcal conjugate vaccine (MCv4) - 11 to 55 yr old
46
Meningococcal Meningitis:
| Describe the lab diagnosis
- essential
- takes a gram stain of CSF
- cultures it
- counts white cell count
47
Haemophilus Meningitis:
| What causes it?
Haemophilus influenzae B
48
Haemophilus Meningitis:
| How many serotypes of Haemophilus influenzae B are there?
six serotypes a-f based on capsules
49
Haemophilus influenzae B:
| Natural resident of ??
respiratory tract of infants and children
50
Haemophilus influenzae B:
| What protects infants until 3-4 months when Abs wane
Maternal antibodies
*this provides a window of susceptibility when Abs wane
51
Haemophilus Meningitis:
| Incubation time
5-6 days
52
Haemophilus Meningitis:
| How fatal is it compared to meningococcal and pneumococcal meningitis?
Less fatal than both
53
Haemophilus Meningitis:
| What can it cause?
- hearing loss
- delayed language development
- mental retardation
- seizures
54
Haemophilus Meningitis:
| Is there a vaccine?
- Yes
- HiB vaccine
- given >2 months
55
Pneumococcal Meningitis:
| _____ cause of meningitis
common
56
Pneumococcal Meningitis:
| is _______
encapsulated
57
Pneumococcal Meningitis:
| Carried in _____ of many healthy people
throats
58
Pneumococcal Meningitis:
| Invasion of blood and meninges ____
rare
59
Pneumococcal Meningitis:
| Low levels of capsular Abs allows for _______
susceptibility
60
Pneumococcal Meningitis:
| Abs type _____
specific
61
Pneumococcal Meningitis:
| _____ capsule types
>85
62
Pneumococcal Meningitis:
| Compare the mortality rate to Haemophilus Meningitis and Meningococcal Meningitis
Mortality rate of pneumococcal meningitis > HiB and meningococcus
63
Pneumococcal Meningitis:
| Is there a vaccine?
Yes
64
Pneumococcal Meningitis:
| Which vaccine is for 2-23 months and immunocompromised?
Heptavalent protein-conjugate
65
Pneumococcal Meningitis:
| Which vaccine is for children > 5 years?
23-valent
66
Neisseria meningitidis:
| Patients?
children and adolescents
67
Neisseria meningitidis:
| Important clinical features?
```
acute onset (6-24 hr)
skin rash
```
68
Neisseria meningitidis:
| Mortality (% of treated cases)
7-10
69
Neisseria meningitidis:
| Sequelae (major CNS deficit, in addition, up to 10% of patients develop deafness)
<1
70
Haemophilus influenzae:
| Patients?
children <5 yrs
71
Haemophilus influenzae:
| Important clinical features?
onset often less acute (1-2 days)
72
Haemophilus influenzae:
| Mortality (% of treated cases)
5
73
Haemophilus influenzae:
| Sequelae (major CNS deficit, in addition, up to 10% of patients develop deafness)
9
74
Streptococcus pneumoniae:
| Patients?
all ages, especially children under 2 and elderly
75
Streptococcus pneumoniae:
| Important clinical features?
acute onset may follow pneumoniae and or septicaemia in elderly
76
Streptococcus pneumoniae:
| Mortality (% of treated cases)
20-30
77
Streptococcus pneumoniae:
| Sequelae (major CNS deficit, in addition, up to 10% of patients develop deafness)
15-20
78
Viral Meningitis:
| most ______ type
common
79
Viral Meningitis:
| ____ than bacterial meningitis
milder
80
Viral Meningitis:
| symptoms?
headache
fever
light sensitivity (photophobia)
*milder symptoms than bacterial meningitis
81
Viral Meningitis:
| complete recovery is _____
typical
82
Viral Meningitis:
| Difficult to isolate virus from CSF so how is diagnosis done?
with a viral genome detection
ex. PCR
83
Viral Meningitis:
| ______ is often the cause
enteroviruses
84
Encephalitis
inflammation of brain parenchyma
85
Encephalitis:
| Is it usually viral or bacterial?
viral
86
Encephalitis:
| _______ dysfunction is typical
cerebral
87
Encephalitis:
| What does cerebral dysfunction cause?
abnormal behaviour, seizures, nausea, vomiting, fever
88
Encephalitis:
| What virus is the most common cause?
HSV (herpes simplex virus)
89
How can neonates get HSV encephalitis?
passage down birth canal of female shedding HSV-2
90
How can older children and adults get HSV encephalitis?
HSV-1 viral reactivation in nerves in skull (trigeminal ganglia) and the infection spreading back to temporal lobe of brain
91
HSV Encephalitis:
| ___% fatality if not treated
70
92
HSV Encephalitis:
| Treatment?
Antiviral therapy for 21 days
93
Poliovirus Encephalitis:
| Used to be the ______ cause of encephalitis
common
94
Poliovirus Encephalitis:
| Symptoms?
1-4 days of fever, sore throat, malaise, followed by signs of meningitis
affect on motor neurons - can cause paralysis
95
Poliovirus Encephalitis:
| Global efforts have _____ polio
eradicated
96
West nile virus:
| Carried by?
- Birds and culicine mosquitoes
| - Humans and horses, incidental hosts
97
West nile virus:
| Previously in ____ and ______________
Africa
| Middle East
98
West nile virus:
| In the 1999 outbreak, how was this spread?
migrating birds
99
West nile virus:
| How do you diagnose it?
WNV RNA detection of IgM Ab in sera/CSF
100
West nile virus:
| Is there a vaccine?
no
101
West nile virus:
| How do you control it?
mosquito control
102
West nile virus:
| What suggested neurological conditions may arise from WNV?
- MS
- Parkinson's
- Schizophrenia
- Senile dementia
103
Summary:
| ____ limits the spread of infection to CNS
BBB
104
Summary:
Once BBB is crossed, pathogens can cause neurologic disease by involving the meninges to cause _______ or the brain substance to cause __________.
meningitis
encephalitis
105
Summary:
| _____ meningitis most common
Viral
