Bacterial infections of the CNS I Flashcards
What are predisposing factors to pneumococcal meningitis?
Pneumonia and chronic otitis media
What are predisposing factors to meningococcal meningitis?
History of recent URTI (viral), complement deficiencies
What percent of patients with bacterial meningitis present with fever, headache, and stiff neck?
50%
What percent of patients with bacterial meningitis will present with two of the following: fever, headache, stiff neck, altered mental status?
100%
What abnormalities in CSF are more indicative of bacterial infection as opposed to viral?
Presence of PMNs, decreased glucose
What is the most common cause of bacterial meningitis among all age groups?
S. pneumoniae (50%)
What is the most common cause of bacterial meningitis among kids less than 2 YEARS of age?
Group B strep
What is the most common cause of bacterial meningitis among kids less than 2 MONTHS of age?
S. agalactiae (GBS)
Which two pathogens predominate in teenage bacterial meningitis infections?
Neisseria and S. pneumo
What is the gram stain for S. pneumo?
Gram positive
What is the catalase test for S. pneumo?
Negative
Does S. pneumo have a capsule?
Yes, virulent strains have polysaccharide capsule
What is the hemolysis pattern for S. pneumo?
Alpha (green)
How do you distinguish S. pneumo from other alpha-hemolytic streptococci?
S. pneumo is optochin sensitive and sensitive to bile (lysed by bile)
What are the pneumococcal virulence factors?
- Choline binding proteins 2. Pneumolysin 3. IgA protease 4. Polysaccharide capsule
What is the diagnosis for pneumococcal meningitis?
- Clinical signs 2. Gram stain of CSF 3. Latex agglutination for capsular antigens 4. Cultivation, biochemical analysis, susceptibility testing
What is the treatment for pneumococcal meningitis?
- Penicillin 2. Vancomycin with a cephalosporin 3. 10-14 days
What is the pneumococcal polysaccharide vaccine made of?
Purified polysaccharide capsular antigen from 23 types of pneumococcus
Is PPV effective in children less than 2 years of age?
No
What are the recommendations for PPV?
- Over age 652. Over age 2 only with immuno suppression
What is the pneumococcal conjugate vaccine made of?
- Conjugated to nontoxic diptheria toxin 2. 13 capsular serotypes
Which pneumococcus vaccine is recommended for children less than 2 years of age?
PCV13
What is the gram stain for Neisseria meningitidis?
Gram negative
What is the shape of Neisseria meningitidis?
Coffee or kidney bean diplococcus
What is the oxidase test for Neisseria?
Positive
What is the catalase test for Neisseria?
Positive
What sugar(s) does Neisseria ferment?
Oxidizes glucose AND maltose (N. gonorrheae only oxidizes glucose)
What are the clinical symptoms of meningococcal disease?
Abrupt onset of fever, hypotension, petechial rash
How does N. meningitidis gain entry into the CNS?
Crosses BBB within neutrophils
What is the diagnosis for meningococcal meningitis?
- Clinical findings 2. Gram stain of CSF and/or blood - direct observation 3. Buffy coat analysis in peripheral blood smear in cases with only bacteremia 4. Cultivation, biochemical analyses
What is the treatment for meningococcal meningitis?
Penicillin, also empiric treatment with vancomycin and a cephalosporin
Which meningococcal meningitis vaccine is recommended in high-risk people over 2 years of age?
MPV, MPV4
Which meningococcal meningitis vaccine is recommended in people between the ages of 11 and 55?
MCV4 - diptheria conjugated
