Intro to NS Inf Diseases

Question 1

3 major functions of nervous system

Answer 1

sensory, integrative, motor

Question 2

immunologically privileged

Answer 2

mount a partial or different immune responses when exposed to immunologic challenges

Question 3

Microglial cells

Answer 3

derived from monocyte cells
tissue-resident macrophages of CNS
inflammatory macrophages (but less?), also activate T lymphocytes as APC.
TLR2 and TLR9

Question 4

Microglial cells express high levels of ____ and _____

Answer 4

TLR2 and TLR9

Question 5

TLR2

Answer 5

recognizes peptidoglycans, lipoproteins…

gram + bacteria, trypanosomes (bruceii – ASS)

Question 6

TLR9

Answer 6

recognizes CpG unmethylated dinucleotides, dinucleotides, herpes virus components, hemozoin

bacterial DNA, some herpesviruses, malaria parasite heme byproduct

Question 7

Normal biota of CNS

Answer 7

none?

Question 8

Defense of CNS

Answer 8

body structures (bone), blood-brain barrier, microglial cells, macrophages

Question 9

Inflammation of meninges =

Answer 9

meningitis

Question 10

____ (#) organisms cause meningitis

Answer 10

many

Question 11

more serious meningitis caused by _______ (organism type)

Answer 11

bacteria

Question 12

Initial infection facilitated by _______ –> meningitis

Answer 12

Upper respiratory infection

Question 13

When meningitis is suspected, _______ (test)

Answer 13

lumbar puncture

CSF gram-stained and potentially cultured

Question 14

Sxs meningitis

Answer 14

photophobia, headache, painful and/or stiff neck, fever, usually increased WBC in CSF

Question 15

Empiric treatment for meningitis

Answer 15

Covers N. meningitidis d/t high fatality rate

Ceftriaxone

Question 16

Major causes of meningits

Answer 16

N. meningitidis
Strep pneumoniae
H. influenzae
Listeria monocytogenes
Cryptococcus neoformans
Coccidioides immitis
variety of virus

Question 17

gram-negative diplococci (remember N. gonnohhreae). Associated with epidemic forms of meningitis. Most serious form of acute meningitis. Portal of entry for this pathogen is through the upper respiratory tract.

Answer 17

N. meningitidis

Question 18

N. meningitidis type of bacteria

Answer 18

gram-negative diplococci

Question 19

N. meningitidis associated with ___ forms of acute meningitis

Answer 19

epidemic, most serious form

Question 20

portal of entry for N. meningitidis

Answer 20

upper respiratory tract

Question 21

Gram-positive coccus - most common cause of bacterial pneumonia. Most frequent cause of community-acquired meningitis. Often associated with alcoholics, sickle-cell individuals, or those with absent of deficient spleen function.

Answer 21

S. pneumoniae

Question 22

S. pneumoniae type of bacteria

Answer 22

Gram + coccus

Question 23

gram-negative coccobacillus. Human only pathogen. Also starts as an upper respiratory infection.

Answer 23

Haemophilus influenzae

Question 24

H. influenzae type of bacteria

Answer 24

gram-neg coccobacillus

Question 25

route of entry H influenza

Answer 25

upper respiratory infection

Question 26

gram-positive bacterium. Listeriosis in elderly, immunocompromised patients, fetuses, neonates affects the brain and meninges. Death rate 20%

Answer 26

Listeria monocytogenes

Question 27

L. monocytogenes type of bacteria

Answer 27

gram + bacterium

Question 28

chronis menigitis. (unless immunocompromised). Fungus. Most common reservoir is in the bird population. Prevalent in urban areas (pigeons). Proliferates in bird poop. Dried yeast cells spread via the wind, etc. Portal of entry is the lung.

Answer 28

Cryptococcus neoformans

Question 29

Cryptococcus neoformans is a ______

Answer 29

fungus

Question 30

C. neoformans portal of entry

Answer 30

lung

Question 31

fungal infection. Begins as a fungal infection of the lungs but can quickly turn into a systemic infection. Can also cause osteomyelitis and skin granulomas. Most common in the Southwest of the US.

Answer 31

Coccidioides immitis

Question 32

Coccidioides immitis is a ______

Answer 32

fungus

Question 33

Most common causes of neonatal/infant meningitis

Answer 33

``` strep agalaciae (group B strep) and e. coli Cronobacter sakazakii ```

Question 34

Gram-negative bacillus. Most commonly found in the environment. Outbreaks are associated with contaminated powered infant formula. Mortality rates can be as high as 40%.

Answer 34

Cronobacter sakazakii

Question 35

C. sakazakii type of bacteria

Answer 35

gram neg bacillus

Question 36

Encephalitis also involving the meninges. Two structures are closely connected. Infections of these structures can involve each other.

Answer 36

meningoencephalitis

Question 37

2 major causes of meningioencephalitis (specifically)

Answer 37

Naegleria fowleri | Acanthamoeba

Question 38

associated with swimming in warm, natural bodies of fresh water. Infection starts in nasal passages. Uses the olfactory nerve to travel to the brain. In the brain it uses the CSF to further infect other tissues.

Answer 38

Naegleria fowleri

Question 39

– invades broken skin, conjunctiva, lugs and urogenital epitheilia. Enviornmental exposures.

Answer 39

Acanthamoeba

Question 40

Acute encephalitis is almost always a ______ infection (examples)

Answer 40

viral Arboviruses and herpesviruses most common Also JC virus, measles, other childhood rash-associated diseases

Question 41

Symptoms acute encephalitis

Answer 41

Vary, include behavior changes and confusion, decreased consciousness, and seizures. Symptoms related to meningitis are also common.

Question 42

Tx acute encephalitis

Answer 42

Swift therapy with acyclovir can save patients with herpersvirus encephalitis. Empiric therapy with acyclovir is common with suspected encephalitis.

Question 43

Example of arbovirus --> encephalitis

Answer 43

west nile

Question 44

Herpes Simplex Viruses and Acute EE

Answer 44

HSV positive mothers can cause neonatal encephalitis in newborns. Past the age of 5 HSV 1 predominates. Usually a reactivation of dormant HSV from the trigeminal ganglion. Rarely VZV can also be involved.

Question 45

JC virus and Acute EE

Answer 45

polyomavirus w/ seropos rates near 80% in US immune dysfunction --> progressive multifocal leukoencephalopathy (PML) uncommon, generally fatal

Question 46

When encephalitis symptoms take longer to show up and when the symptoms are less striking, the condition is known as _______

Answer 46

subacute encephalitis

Question 47

Most common cause of subacute EE + other causes

Answer 47

Toxoplasma gondii | persistant measles virus (subacute sclerosing panencephalitis), prions (spongiform encephalopathy)

Question 48

slow, progressive zoonotic disease that causes fatal encephalitis

Answer 48

rabies, caused by rabies virus

Question 49

average incubation of rabies

Answer 49

1-2 months depends on wound site and inoculation dose if near scalp/neck, shorter than if distally

Question 50

Symptoms rabies

Answer 50

with fever, headache, vomiting, fatigue, and other nonspecific symptoms --> agitation, disorientation, seizures, and twitching. This is followed by hydrophobia and progressively worsening neurological symptoms leading to coma and death.

Question 51

rabies virus causative agent

Answer 51

ssRNA (-) virus

Question 52

rabies virus encounter, reservoir

Answer 52

zoonotic (animals) --> humans | mostly wild animals (raccoons, skunks, coyotes, foxes, bats, also domestic animals)

Question 53

rabies mode of transmission

Answer 53

The virus, present in the saliva of rabid animals, enters the body through a wound from a bite or through contamination of mucous membranes by the infected saliva. The virus multiplies at the site of inoculation and then travels to the CNS.

Question 54

dx rabies

Answer 54

Observation of tissue samples (brain or corneal tissue) using immunological tests that detect rabies, observation of characteristic inclusion bodies (Negri bodies) in the cytoplasm of nerve cells obtained in tissue samples are taken as confirmation of rabies.

Question 55

Tx rabies

Answer 55

rabies immune globulin (Ab, RIG, buys time for vaccine) at site, intramuscular inactivated rabies virus prep (antigen)

Question 56

rabies prevention

Answer 56

vaccine w/ inactivated rabies for humans and animals

Question 57

Acute enteroviral infection of the spinal cord that can cause neuromuscular paralysis.

Answer 57

poliomyelitis

Question 58

Tetanus caused by

Answer 58

clostridium tetani

Question 59

c. tetani found in

Answer 59

soil, GI tracts of animals

Question 60

C. tetani kind of bacteria

Answer 60

gram + endospore-forming rod | obligate anaerobe

Question 61

C. tetani endospores

Answer 61

Endospores it produces often swell the vegetative cell but are only produced under anaerobic conditions (need deep seeded wounds, poor blood supply)

Question 62

C. tetani releases _______

Answer 62

neurotoxin = tetanospasmin

Question 63

tetanospasmin action

Answer 63

binds to target sites on peripheral motor neurons, on the spinal cord and brain, and in the sympathetic nervous system. The toxin acts by blocking the inhibition of muscle contraction. Without inhibition of contraction, the muscles contract uncontrollably, resulting in spastic paralysis.

Question 64

sxs tetanus

Answer 64

clenching of jaw succession by extreme arching of back, flexion of arms, extension of legs risus sardonicus (eery smile) death by respiratory arrest

Question 65

tetanus tx

Answer 65

is aimed at deterring the degree of toxemia and infection and maintaining patient homeostasis. immediately receive antitoxin therapy with human tetanus immune globulin (TIG). Penicillin G is also administered. cleanse/remove affected tissue to get rid of bound toxins support tx (respirator, trach)

Question 66

Botulism caused be

Answer 66

Clostridium botulinum

Question 67

common cause of death in livestock that have grazed on contaminated food and in aquatic birds that have eaten decayed vegetation.

Answer 67

botulism (associated with eating poorly preserved foods)

Question 68

Botulinum mechanism of action

Answer 68

prevent the release of the acetylcholine, the neurotransmitter that initiates the signal for muscle contraction

Question 69

onset botulism

Answer 69

12-72 hrs depending on dose amt

Question 70

botulism sxs

Answer 70

Neuromuscular symptoms first affect the muscles of the head and include double vision, difficulty in swallowing, and dizziness, but there is no sensory or mental lapse. Although nausea and vomiting can occur at an early stage, they are not common. Later symptoms are descending muscular paralysis and respiratory compromise.