Table 2.

“False Positives” and “False Negatives” of mNGS

Pathogens Detected Only by mNGS in the NID Group
Sample No.	Specimen source	Diagnosis	mNGS result	Possible explanation
2	BALF	Hematencephalon	Acinetobacter baumannii, Klebsiella, Enterococcu	Unknown
33	Blood	Lymphoma	Pseudomonas, CMV	Potential cause of lymphoma
62	Blood	Aplastic anemia	Acinetobacter baumannii, Enterococcu	Overinterpretation
67	Blood	myelofibrosis	Phycomyces blakesleeanus	Overinterpretation
74	Pleural Fluid	Pleural effusion	Fusobacterium nucleatum, Streptococcus constellatus, Porphyromonas gingivalis	Potential cause of inflammation
86	Blood	Ulcerative Colitis	Porphyromonas gingivalis, HSV	Potential cause of inflammation
88	Blood	Lung cancer	Saccharomyces cerevisiae	Overinterpretation
Culturable Pathogens Missed by mNGS in the ID Group
Microbe		Count	Possible explanation
MTB		2	Positive Not Detected
Pseudomonas		1	Microbes “Weak”

Abbreviations: mNGS metagenomic next-generation sequencing, ID infectious disease, NID noninfectious disease, CMV metagenomic next-generation sequencing, HSV herpes simplex virus, MTB Mycobacterium tuberculosis