Meningitis: PCR may help diagnose meningococcal meningitis

Clinical bottom line (level 4)

Polymerase chain reaction may help diagnose and exclude meningococcal meningitis in patients undergoing lumbar puncture.

Ni et al: Lancet 1992; 340: 1432-1434

Expires November 2003

The study

Setting: acute hospital, UK

54 patients (aged ?, ?% male) who underwent lumbar puncture - some for suspected meningitis

Independent blinded reference standard, applied in all patients from a non-consecutive inappropriate spectrum.
Reference standard:

CSF culture or microscopy

Diagnostic test: polymerase chain reaction (PCR)

The evidence

pre-test probability of meningococcal meningitis: 20%, (95% CI: 9.6% to 31%)

diagnostic test	meningococcal meningitis	other disease	LR+ (95% CI)	post-test probability	LR- (95% CI)	post-test probability
PCR	10	4	9.7 (3.7 to 25)	71%	0.10 (0.015 to 0.65)	3%
total	11	43

Comments

At the moment, although PCR is rapidly evolving, its main application in bacterial meningitis would be to identify causative agents not detected by other ways and in a non-emergency base

Citation

Ni H, Knight AI, Cartwright K, et al: polymerase chain reaction for diagnosis of meningococcal meningitis. Lancet 1992; 340: 1432-1434

Search Terms:
Contributor: Chris Ball and Clare Wotton, November 1999
Reviewer: Luis Ruiz Del Fresno

_{Clinical Question.}

_Patient	_{suspected meningococcal meningitis}
_{Intervention or Exposure}	_PCR
_Outcome	_{confirmed meningococcal meningitis}