Accuracy of real-time PCR, Gram stain and culture for Streptococcus pneumoniae, Neisseria meningitidis and Haemophilus influenzae meningitis diagnosis

Table 5 Characteristics of patients with isolated positive RT-PCR results

	Culture-Gram-PCR result^b
	All tests negative	Isolated RT-PCR positive	All tests positive
	(n=329)	(n=20)	(n=75)
Age in years (median, range)	9 (0–64)	11 (0–63)	15 (0–78)
Altered mental status (%)	66 (22.6)	6 (40.0)	47 (66.2)
Deaths (%)	27 (9.1)	2 (10.5)	10 (14.3)
Median WBC (x10⁶ cells/L, range)^c	430 (100–10,000)	10,000 (32–10,000)	8,600 (0–10,000)
>50% PMN cells (%)	186 (56.7)	18 (90.0)	72 (96.0)
Median protein (g/L, range)^d	0.50 (0.20-5.00)	2.90 (0.32-5.00)	3.50 (0.28-5.00)
Median glucose (mmol/L, range)	2.9 (1.1-3.9)	1.6 (0.6-3.1)	1.1 (1.1-3.2)
LAT positive (% of total LAT performed)	1 (2.0)	5 (38.5)	25 (80.6)
Positive LAT concordant with RT-PCR (%)^e	n/a	5 (100.0)	25 (100.0)
Antibiotic bioassay positive (%)	28 (8.8)	12 (63.2)	41 (55.4)

Patients with isolated positive RT-PCR results are compared with patients with all negative or all positive culture, Gram stain, and RT-PCR test results.^a
Abbreviations: WBC, white blood cells; PMN, polymorphonuclear; LAT, latex agglutination test; n/a, not applicable.
^aPatients with missing data exclude from calculations.
^bPositive or negative for N. meningitidis, S. pneumoniae, or H. influenzae as defined in Methods.
^cMaximum value truncated at 10,000 x10⁶ cells/L.
^dMaximum value truncated at 5.00 g/L.
^eNumber and percentage of positive latex agglutination test results that were consistent with RT-PCR result.

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