Chapter 22: Microbial Diseases of the Nervous System

Question 1

Meningitis

Answer 1

Meningitis is the inflammation of the meninges (3 layers). occurs when there is an accumulation of WBC and swelling

Symptoms:

1. Initial: nausea, violent vomiting, severe headaches
2. stiff neck (kernig’s sign used for children, tight hamstrings)
3. convulsions (coma)
4. death

Diagnosis:

1. needs to be rapid, within 24 hours
2. lumbar puncture
3. CSF sample
   - gram stain will indicate treatment
   - 3rd generation of cephalosporins
   - culture takes 1/2 a day
   - serology: Ig molecules prepared, added to mixture

Question 2

Hemophilus influenzae

Answer 2

• 6 months to 4 years
• 6 strains A-F.
• B occurs in 95% of the strain
• meningitis

preventions
- Hib - for strain B

Question 3

Neisseria meningitidis

Answer 3

• rapid diagnosis and prevention are crucial
• saliva is a common carrier
• demographic: children up to 5, young adults 19-24, prisoners
• strains: A, B, C, WB5, Y. C most common

symptoms

• throbbing headache
• sore throat
• once in the blood, can cause tissue damage
  1. petechiae: blue/purple dots
  2. amputation
  3. paralysis
  4. deafness

Question 4

Streptococcus pneumoniae

Answer 4

• 82 strains
• demographic: children up to the age of 5 (30% mortality) and elderly population (80% mortality rate)
• prevention and vaccination

entry points:

• sinusitis
• otitis media
• head/neck, surgery/trauma

Question 5

Listeria monocytogenes

Answer 5

• spread by food - listeriosis
• reproduces in monocytes/macrophages
• meningitis

demographic:
- immunosuppressed (cancer, smokers, alcohol, older men)
- pregnant women: can transfer to the baby
1. ill newborn (60-65)
2. still born baby
3. miscarriages

Question 6

Eschercheria coli

Answer 6

• transferred through the birth canal

Question 7

Tetanus

Answer 7

• A and B exotoxin
• caused by clostridium tetani
• grows in deep wounds
• tetanus exotoxin blocks relaxation pathway in muscles and results in spasms
• prevention by vaccination with tetanus toxoid (DTP) and booster (Dt)

Symptoms

1. restlessness
2. irritability
3. stiff neck
4. lockjaw
5. back spasms - opisthotonos
6. CV/respiratory - death
   - Inhibits GABA (gamma, aminobutyric acid) at the neuromuscular junction

Question 8

Botulism

Answer 8

• caused by clostridium botulinum
• intoxication begins by ingesting botulinum toxin
• botulinum toxins blocks the release of the neurotransmitter, Ach, causing flaccid paralysis
• lethal form
• 12-36 hours
• A-B exotoxin: inhibits Ach at the NMJ, causes paralysis

symptoms

1. dry mouth
2. abdominal discomfort
3. diarrhea/constipation
4. blurred vision
5. CV/resp - death

strains:

• A, B, E, F in humans
• C, D, F, for non-humans
• A is the worst

Question 9

Poliomyelitis (Polio)

Answer 9

• poliovirus
• transmission by ingestion
• sustained viremia can cause destruction of motor cells and paralysis occurs in < 1% of cases
• prevention: vaccination (salk and sabin polio vaccine)
• fecal-oral route (H20/feed)
• india 2012, successful vaccination 1.34 billion. SDOH

initial symptoms
1. sore throat, nausea, small intestine
2. lymph and blood
- viremia: 
transient form - no symptoms
persistent form - moves into CNS, attacks motor neurons, causes paralysis
1954: Jonas Salk
1. IPV
2. safe
3. booster

1963: Albert Sabin, 1/14 cases
1. OPV
2. expensive
3. oral