Meningitis: Multiplex viral PCR appears excellent in diagnosis

Clinical bottom line (level 4)

In patients with suspected meningitis, viral PCR on CSF rules in (LR+-) or out (LR+0.01) the condition.

Read et al: Journal of Clinical Microbiology 1997; 35 (3): 691-696

Expires September 2003

The study

Setting: diagnostic microbiological laboratory in UK

1962 patients (aged ?, 55% female) with possible meningitis

Independent unblinded reference standard, applied in all patients from a consecutive appropriate spectrum.
Reference standard:

assessment of minimal viral load in culture media; clinical corroboration

Diagnostic test: viral PCR to detect enterovirus, HSV(1&2&untyped), VZV, EBV, CMV, HHV-6, JCV

The evidence

pre-test probability of viral meningitis: 7.5%, (95% CI: 6.4% to 8.7%)

diagnostic test	viral meningitis	other cause for symptoms	LR+ (95% CI)	post-test probability	LR- (95% CI)	post-test probability
multiple viral PCR	143	0	inf (240 to inf)	100%	0.01 (0.00 to 0.05)	0%
total	145	1781

Comments

PCR has evolved as its own golden standard, thereby validating and biasing results at the same time.
Clinical utility has been difficult to prove, but there is emerging evidence of usefulness (e.g. Ramers 2000)

Citation

Read SJ, Jeffery KJM, Bangham CRM: Aseptic meningitis and encephalitis: the role of PCR in the diagnostic laboratory. Journal of Clinical Microbiology 1997; 35 (3): 691-696

Contributor: Bob Phillips and Clare Wotton, February 2000
Reviewer: Dirk Stengel

_{Clinical Question.}

_Patient	_{signs of meningitis}
_{Intervention or Exposure}	_{viral PCR}
_Outcome	_{viral meningitis}