Table 3.

Diagnostic performance of CSF mNGS for common opportunistic CNS diseases¹.

	Sensitivity	Specificity	PPV	NPV
	(95%CI)	(95%CI)	(95%CI)	(95%CI)
EBV-associated CNS disorder 2	100	NA3	NA	100
	(72.25-100)			(90.11–100)
CMV encephalitis	100	NA	NA	100
	(74.12–100)			(92.87–100)
PML	92.86	100	100	98.36
	(68.53–98.73)	(93.98–100)	(77.19–100)	(91.28–99.71)
CNS tuberculosis	40	97.1	50	95.71
	(11.76–76.93)	(90.03–99.20)	(15.00–85.00)	(88.14–98.53)
Toxoplasma encephalitis	100	100	100	100
	(60.97–100)	(94.65–100)	(60.97–100)	(94.65–100)
Cryptococcal meningitis	100	100	100	100
	(67.56–100)	(94.50–100)	(67.56–100)	(94.50–100)

CSF, cerebrospinal fluid; mNGS, metagenomic next-generation sequencing; PPV, positive predictive value; NPV, negative predictive value; EBV, Epstein–Barr virus; CMV, cytomegalovirus; PML, progressive multifocal leukoencephalopathy; and CNS, central nervous system. ¹For the purpose of illustration, all six patients with undetermined causes of neurological symptoms had been excluded from analysis. Finally, diagnostic performance of CSF mNGS was calculated from 74 samples. ²CNS lymphoma or EBV encephalitis. ³EBV and CMV were commonly detected by CSF mNGS. Some of the positive detections were not associated with CNS disorder, and also could not be considered as false positive either. Therefore, the specificity and PPV were not calculated.