Infectious Diseases II

Question 1

What is the most likely organism of meningitis in a child < 2 years old?

Answer 1

Group B Streptococcus (e.g. S. algalactiae)

Gram -ve enterics (e.g. E. coli)

Question 2

What is hte most likely organism of meningitis in patients 2-50 years old?

Answer 2

S. pneumoniae
N. meningitidis
H.influenzae

Question 3

What is first Tx for meningitis?

Answer 3

3rd GEN CEPHALOSPORINS - cefotaxime or ceftriaxone

Question 4

When are penicillins used to treat meningitis?

Answer 4

USED - if caused by meningococci or listeria

NOT USED if caused by H. influenzae - due to resistance emerging from β-lactamase enzymes produced by H. influenzae

Question 5

What adjunctive treatment is given to a patient with meningitis and why?

Answer 5

CORTICOSTEROIDS (DEXAMETHASONE)

Corticosteroids can be given to the patient to reduce the risk of cerebral oedema and lower the intracranial pressure.

[They work by reducing the synthesis of pro-inflammatory cytokines such as TNF-alpha and IL-1 beta from monocytes and astrocytes, thus reducing cerebral oedema.]

Question 6

When would this adjunctive treatment be started?

Answer 6

Either before or with the first dose of the 3rd generation cephalosporin, but must NOT be given any later than 12 hours after the first dose of the antimicrobial.