Microbiology in Bacterial Meningitis

六隻：S.N.H.L.E.S

(NEJM 2011;364:2016)

S. pneumoniae (30–60%)

• Look for preceding infection (bacteremia, pneumonia, endocarditis)
• Drug-resistant S. pneumoniae:
• ~40% PCN-resistant (even intermediate resistance problematic)
• ~<10% 3rd-gen. cephalosporin-resistant
• Microbiology-of-Pneumonia
• See “Pneumonia” for S. pneumoniae vaccination recs
• Prevention-pneumonia.md

N. meningitidis (10–35%)

• Primarily in age <30 y; associated petechiae or purpura
• ↑ risk in asplenia, complement defic., HIV, SCT, unvaccinated
• Vaccine rec for all age 11–18 y, HIV infection, asplenia, C5-9 deficiency

H. influenzae (<5%)

↑ risk in asplenia, complement defic., HIV, SCT, unvaccinated, CSF leak, trauma/surgery, mastoiditis Vaccine rec for all children; markedly ↓ incidence

L. monocytogenes (5–10%)

↑ in immunosupp (glucocorticoids, transplant), elderly, malignancy, pregnant, cirrhosis. Outbreaks a/w contaminated dairy & raw veg.

GNRs (1–10%)

More common in health care associated meningitis (E. coli, Klebsiella sp., Pseudomonas aeruginosa)

Staphylococci (5%)

Preceding infection (endocarditis, bacteremia), post CNS surgery, foreign bodies (CSF shunt, intrathecal pump)

Mixed infection

Suspect parameningeal focus or CSF leak, post CNS surgery