Bacterial and Fungal Meningitis Flashcards
Is meningitis usually cause by viruses or bacteria/
Viruses
Is meningitis usually cause by viruses or bacteria/
Viruses
Is encephalitis usually caused by viruses or bacteria?
Viruses
Insidious onset of fever, headache +/- neck stiffness, altered consciousness, seizures, focal neurological signs.
Brain abscess
Are brain abscesses usually caused by viruses or bacteria?
Bacteria, may be parasitic
What are the 2 main ways in which microorganisms can invade the brain?
Blood bourne invasion-blood brain barrier or blood CSF barrier
Peripheral nerves
Describe the appearance of neisseria meningitidis
Gram -ve diplococci
What does neisseria meningitidis, haemophilus influenzae and streptococcus pneumonia all have in common with regards to their requirements for growth?
All require blood
Give 5 examples of the capsular types of neisseria meningitidis
A, B, C, W135, Y
Where is the natural habitat of neisseria meningitidis?
Nasopharynx
Is what demographics of people is neisseria meningitidis carried in?
Smokers, uni students
Name 2 virulence factors for neisseria meningitidis
Capsulated
Acquires iron from transferin
Name 6 ways in which neisseria meningitidis presents
Septicaemia Septicaemia with purpuric rash Septicaemia with meningitis Meningitis with no rash Chronic meningococcal bacteraemia with arthralgia Focal sepsis Conjunctivitis, endopthalmitis
What does purpuric mean?
non blanching
Treatment for neisseria meningitidis, haemophilus influenzae and streptococcus pneumonia
Ceftriaxone, cefotaxime, penicillin (NM), ampicillin (HI)
In which type of bacteiral meningitis is chemoprophylaxis of contacts of invasive disease NOT routinely done?
Streptococcus pneuomoniae
The current vaccinations against Neisseria meningitidis target which strains?
Group A,C and W135. None againsts group B
Where in the world is epidemics of neisseria meningitidis common? Usually group A
Arican meningitis belt
Describe the appearance of haemophilus influenzae
Gram -ve bacilli
What are the different strains of haemophilus influenzae and which is the most invasive disease?
a-f. B
Virulence factors of haemophilus influenzae
Type B capsule
Fimbriae
IgA proteases
Vaccines are available for what strain of haemophilus influenzae?
Type B
Vaccines are available for what strain of haemophilus influenzae?
Type B
Is encephalitis usually caused by viruses or bacteria?
Viruses
Insidious onset of fever, headache +/- neck stiffness, altered consciousness, seizures, focal neurological signs.
Brain abscess
Are brain abscesses usually caused by viruses or bacteria?
Bacteria, may be parasitic
What are the 2 main ways in which microorganisms can invade the brain?
Blood bourne invasion-blood brain barrier or blood CSF barrier
Peripheral nerves
Describe the appearance of neisseria meningitidis
Gram -ve diplococci
What does neisseria meningitidis, haemophilus influenzae and streptococcus pneumonia all have in common with regards to their requirements for growth?
All require blood
Give 5 examples of the capsular types of neisseria meningitidis
A, B, C, W135, Y
Where is the natural habitat of neisseria meningitidis?
Nasopharynx
Is what demographics of people is neisseria meningitidis carried in?
Smokers, uni students
Name 2 virulence factors for neisseria meningitidis
Capsulated
Acquires iron from transferin
Causes of lymphocytic meningitis
Viruses
Spirochete (type of bacteria)
TB
Crytococcus
What does purpuric mean?
non blanching
Treatment for neisseria meningitidis, haemophilus influenzae and streptococcus pneumonia
Ceftriaxone, cefotaxime, penicillin (NM), ampicillin (HI)
In which type of bacteiral meningitis is chemoprophylaxis of contacts of invasive disease NOT routinely done?
Streptococcus pneuomoniae
Diagnosis for brain abscesses
Brain imaging
Where in the world is epidemics of neisseria meningitidis common? Usually group A
Arican meningitis belt
Describe the appearance of haemophilus influenzae
Gram -ve bacilli
What are the different strains of haemophilus influenzae and which is the most invasive disease?
a-f. B
Which age group is haemophilus influenzae most common in?
infants
Virulence factors of haemophilus influenzae
Type B capsule
Fimbriae
IgA proteases
Chemoprophylaxis of contacts is done using what antibiotic?
Rifampicin
Vaccines are available for what strain of haemophilus influenzae?
Type B
Another name for streptococcus pneumoniae
Pneumococcus
Describe the appearance of strep. pneumoniae
Gram +ve cocci. Cells arrange in pairs
How is strep pneumoniae transmitted?
Droplet
What diagnostic test confirms pneumococci?
Optochin
What treatment is given at the same time as antibiotics in adults for treatment of strep. pneumo meningitis?
Steroids (dexamethosome) It decreases the concentration of vancomycin in the CSF, so rifampicin must be used as well.
3 common causes of neonatal meningitis
Group B beta-haemolytic streptococci
E.Coli
Listeria monocytogenes
At what age is septicaemia the diagnosis, compared to meningitis
less than 2 days old- septicaemia (early)
more than 5 days old- meningitis (late)
Treatment for neonatal meningitis
Cefotaxime, ampicillin, gentamycin
Complications of meningitis
Death
Overwhelming sepsis
Increased intracranial pressure
Long term problems of meningitis
Deafness, delayed development, seizures, stroke, hydrocephalus
Another term for lymphocytic meningitis
Aseptic
Causes of lymphocytic meningitis
Viruses
Spirochete (type of bacteria)
TB
What is the likely causative organism for insidious onset meningitis in immunocompromised or alcoholics
TB
Likely causative organism for brain abscess that has spread from adjacent structures e.g. middle ear or sinuses
Streptococci anaerobes
Likely causative organism for brain abscess that has spread from blood stream
Staph A
Diagnosis for brain abscesses
Brain imaging
Meningitis caused by a yeast, insidious onset
Crytococcal meningitis
How is cryptococcus identified in CSF?
Indian Ink Stain
What is the treatment for cryptococcal meningitis?
Amphotericin, flucytosine or fluconazole
Which lobes does encephalitis preferentially affect?
Temporal lobes
Give 3 organisms that cause toxin mediated CNS infections
Japanese encephalitis virus
Rabies encephalitis
Clostridium tetani
What type of virus is japanese encephalitis virus?
Arbovirus (transmitted by mosquitoes, ticks or arthropods)
What percentage of people die from rabies encephalitis?
100% if untreated
Describe the appearance of clostridium tetani
Gram +ve forming bacillus ‘drumstick’ anaerobe
How is clostridium tetani commonly transmitted
Contaminated soil infecting wounds
How does clostridium tetani produce a convulsive contraction of voluntary muscles?
toxin spreads in bloodstream and binds to ganglioside receptors and blocks release of inhibitory interneurones
The word for jaw spasms
trismus
Spin arching spasm
Opisthotonus
What are the clinical signs of tetanus (lock jaw)
tonic muscle spasms trismus opisthotonus respiratory difficulties cardiovascular instability
Treamtnet for tetanus
antitoxin
Penicillin or metronidazole
Prevention for tetanus
Toxoid