Lecture 5: Infectious Disease Affecting the Nervous System Flashcards
BBB
- allows passage:
a. water
b. some gases
c. lipid-soluble molecules
all by passive diffusion - selective transpor amino acids
- tight junctions create barrier
- prevents entry lipohillic potential neurotoxins and pathogen
- major consideration when choosing therapy
P glycoprotein
gatekeeper of BBB
-can be an issue for abx
Acute bacterial meningitis
rapidly developing bacterial infection of meninges
Most dangerous form ABM caused by what pathogen?
Neisseria Meningitidis causes meningococcal meningitis
Neissiera meningitis characteristic
aerobic, g(-) diplococcus
Neissiera meningitis
transmission
prevalent where
prevention
t: person-person transfer of large droplet respiratory secretions
prevalent: where people are in close proximity for long periods time: jails, ,college dorms, military camps, etc
prevention: vaccine fo r kids and adults
- menveo, menacer, minenrix (with tetanus)`
Streptococcus pnuemoniae
- characteristics
- causes what disease
- what %
- mortality % - prevention
causative agent for bacterial meningitis
- pairs or short chains
- causes pneumococcal meningitis as well as pneumonia
- 30% ABM cases
- high mortality rate 20-30% - VAX- pnemovax >64 yrs, prevanar 13 for < 5 years or > 64 years
Pneumovax 23
> 64 years
Prevnar 13
pneumococcal vaccine <5 yrs or > 64 yrs
Haemophilus inlufenzae type B
- once most prevalent species causing bacterial meningitis in american children but now there ic vaccine
- less than 40 cases of homophiles meningitis in US
- VACCINE
Pathogenic steps leading to meningitis
- organism disseminates, rash appears
bright red patches -> blue black spots - once in blood, organisms pass BBB
- meninges becomes inflamed
- pressure on spinal cor and brain casue fever and stiff neck
- N/V/
- sensitivity to bright light
- can die within hours
* petechaie and purpura
3 organisms causing Meningitis
- haemophilus influenzae
- streoptoccus pnemoniae
- neissieria meningitis
ABM IS MEDICAL EMERGENCY (4)
- early dx and tx are crucial to prevent disabilities and death
- seriousness demands tx before results of diagnostic tests are known
- IV OF PENICILLIN, CEFOTAXIME, CEFTRIAXONE
- vaccines exist but no single vaccine provides immunity to all forms of meningitis
Clinical presentation meningitis
- HA
- Stiff neck
- fever
- altered mental status
- coma
- brudzinski’s sign and kernels sign
Brudzinski’s sign
if head is pulled upward, legs will pull inward
Listerioris
waht pathogen
transmission
- causes by listeria monoctyogenes
- eating contaminated food
- contaminated with feces
- contamintied animal products like cold cuts and soft cheeses - psychotrophic: cold tempereatures do not affect growth
Listeria monocytogenes characteristics
gram (+) rod or coccobacilli
psychotrophic
Clinical presentationif listerosis
incubaiton
sx
special pop (3)
- 2-6 week incubation
- most healthy people don’t experience sx
- menigitis in immunocompromised can cause coma, mental status change - affects pregnant women, immunocompromised, elderly
- can infect fetus and cause miscarriage or still birth - 45% mortality if it gets into bloodstream
Meningoencephalitis sx (5)
- stiff neck
- HA
- fever
- delerium
- coma
Tx listeriosis
- 2 week antibiotic tx
- ampicillin or penicillin PLUS gentamicin - delay in tx assoc. with poor outcomes
- longer course tx for immunocompromised
prevention listeriosis
- throtoughly cook raw food
2. wash hands, knives, cutting boards
Listeria -> brain/meninges (4)
- ingested
- invades epithelium cells in GI
- moves in and between cells useing hot cell actin tail formaiton
- invades macrophages to get into blodstread wheret can cross BBB
Tetanus
pathogen
complications
- clostridium tetani
- causes hyperactive muscles contractions
- toxin tetanospasmin inhibits compounds needed to inhibit muscle contraction
- uncontrolled muscle contraction
clostridium tetani characteristic
causes tetanus
aerobic gram (+) endospore-forming
Sc tetanus intoxicaiton
- develop rapidly
- trismus (lockjaw): spasms jaw muscles, clenching of teeth
- Opisthotonus invokes muscles spasms that cause an arching of back
- spasmodis inhalation and seizures in diaphragm and rib cage- reduce ventilation
Trismus
lockjaw
Opisthotonnus
muscle spasms causing arching of back
Tx tetanus (3)
- sedative
- muscle relaxant
- penicillin
Tetanus prevention
toxoid used in tx and vaccination
- DTap for kids
- Tdap 11-12 ys
- Tdap or Td at 10 year intervals fo adults
Clostridium botulism pathogen charcteristics(4)
- spore forming
- anaerobe
- G (+) rod
- causes botulism
C. boutlism complications
produces dealdly exotoxin
- attack nervous system
- flaccid paralysis
Botulism tx
large doses antitoxins can neutralize toxin if treated early
-most outbreaks due to home-canned foods or foods eaten cold
*boiling deserts toxin
Botulism toxin affects in body (4)
- inhibits release acetylcholine
- nerve impulses can’t pass snypase
- no muscle contraciton
- flaccid paralysis
Botulism variants (3)
- wound botulism, when wound infected with c. botulism
- infant botulism AKA floppy baby, when infant fed honey
- minute doses botulism toxin can treat movement disorders, wrinkles, hyperhidrosis, migraine
Leprosy
pathogen
transmission
incubation
Hansen disese
- mycobacterium leprae
- spread through nasal secretions
- 3-6 year incubation
Mycobacterium Leprae characteristsis
- obligate
- intracellular parasite
- acid fast abacilli
Complications leprosy
- multibacjilliary or lepramatous leprosy, tumor-like lepromas form
on skin and respiratory tract
- numbless and muscle weakness
- thickening peripheral nerves
- can lead to disability
Damage to peripheral nerves from leprosy
- leads to deformities
- twisting of limbs, curlings of fingers, loss facial features, glaucoma/blindness
efforts to eradicate leprosy
WHO
dapsone
rifampicin
clofazimine
Viral (aseptic meningitis)
- viruses cause asceptic meningitis
- most caused by enteroviruses
- viral menignitis MILDER than bacterial
Tx viral meningitis
best rest, fluids, more mild than bacterial
Viral encephalitis
- consequence primary or secondary infeciton
- encephalitis imflammaiont of brain
- many viral causes
- some cases due to herpes virus
- can occur in newborns of passed through brith
transmission enteroviruses
most likely respiraroty secretions
Secondary encephalitis
results from viral infection that first occurs elsewhere in the body
can be a late virus that reactivates and travels to brain
ex) VZV, measles, mumps, german measles
Arboviral encephalitis
- primary viral infection
- tx arthropods
- zoonosis-transmitted between animal host to humans by arthropods - most NOT transmitted person-person
- many forms transmitted by mosquitoes and ticks
Arboviral encephalitis sx
- pain head and neck
- convulsion
- coma
Arboviral complication
- paralysis
2. mental disorders
West nile fever
- many infected people remain asymptomatic or are ill for a few days
- rarely can lead to encephalitis or meningitis
- can results in permanent neurological effects or death
- no vaccin or treatment
Zika Virus
- transmitted by mosquitoes
- transmitted mother-child
- transmitted sexually
- 80% asymptomatic
5, 20% develop rash, joing paint, conjunctivitis
Rabies in animal
- furrious rabies
- wide eyes
- drooling
- unprovokes attacked - dumb rabies
- docile, lethargic - wild animals are vaccinated with inoculated dog food and fish meal
Rabies transmission
enters through human skin wound, contaminated with bodily fluid from an infected animal
- incubation 6days-1year
- depends on location of entry and amount of virus entering body
Rabies Sx (7)
- tinglins, burning, coldness at bite side
- fever, HA, increased muscle tension
- alert, aggressive
- paralysis
- brain degeneration
- hydrophobia
- death from respiratory paralysis
Rabies tx
Post exposure immunizaiton can be doe immediate after exposure
Polio virus
may be next eradicated
Abortive poliomyelitis sx
HA, nausea, sore throat
1% passe thorugh bloodstream to meninges
nonparalytic poliomyelitis sx (3)
fever, HA, stiff neck
Paralytic poliomyelitis
paralysis arms, legs, body trunk, facial muscles, tongue, diapragh
Postpolio syndrome PPS
Patient’s who have recovered form polio can sometimes experience symptoms again
- reactivation viruts
- autoimmune reactiom
Trivalent vaccines
contain all 3 strains poliovirus
Cryptococcosis
complication pathogen (2) sx (3) dx (2) tx (2)
- fungal lung disease
- can cause mepningo-ecephalitis in immuno compromoised
- Crypto. Neiforomans and C. gattii
- sx: HA, fever, change in mental status
- dx: spinal tap, MRI
- Tx: amphocetriun B and fluconozole
Coccidiomycosis
pathogen (2)
sx (2)
dx(2)
tx
fungal disease affecting CNS
1. valley fever
- c immitis, c posadasii
- Sx: flu-like, can cause menigitis
- dx: spinal tap
- Tx: ampoceterin B
Primary amoebic meningoencephalitis
pathogen
pathogenesis
tx
- caused by Naegleria Fowleri
- rare: 95% die within 4-5 days
- inhaled from swimming in warm water
- amoeba enters nose and swims ups to the brain along olfactory tracts
- tx with limited success
Tyrpanosomiasis
- disease caused by 2 species of trypanosoma
African sleeping sickness
Pathogen
pathogenesis
- trypanosoma Brucei
- t: tstes fly
- chancre forms at bite site
- paraside invade blood stream and enter CNS
T. brucei variants and their disease (2)
- T. brucei gambiense
- chronic
- fever, HA, change in sleep patterns and behavior, wasting, coma when parasites enter brain - T. brucei rhodesience
- more acute, high fever, rapid coma, death
Toxoplasmosis
pathogen complication transmission special population tx
- toxoplasma gondii
- cause encephalitis in immunocompromised patients
- t: to him and via contaminated pork, before, lamb
- domestic cats acquire it from birds or rhodens - can cross through placenta
- lead to hearing loss, mental disability, lesions in the retina causing blindness - tx: trimethoprim/sulamethox
