Table 6. Comparison of metagenomic NGS results and conventional microbiological tests.

The positive rate of mNGS virus detection was lower than that of serum antibody detection plus PCR (6.7% vs. 26.7%, P = 0.021). mNGS was significantly better at detecting bacteria than serological antibody testing plus PCR (24.4% vs. 0%, P = 0.001). Further, mNGS was able to detect specific pathogens better than the culture method (22.2% vs. 0%, P = 0.001) and serological antibody testing plus PCR (22.2% vs. 2.2%, P = 0.007). Additionally, mNGS was significantly better at the identification of co-infections than serological antibody tests plus PCR (26.7% vs. 0%, P < 0.001). Finally, mNGS proved to be significantly better at identifying pathogens than the culture method (91.1% vs. 62.2%, P = 0.001) and serological antibody testing plus PCR (91.1% vs. 28.9%, P < 0.001).

	Method A (n = 45)	Method B (n = 45)	Method C (n = 45)	P-value, A vs. B	P-value, A vs. C
Only virus, n (%)	3 (6.7)	0 (0.0)	12 (26.7)	0.24	0.021*
Only bacterial, n (%)	11 (24.4)	15 (33.3)	0 (0.0)	0.486	0.001*
Only fungus, n (%)	5 (11.1)	5 (50.0)	0 (0.0)	1	0.056
Special pathogen, n (%)	10 (22.2)	0 (0.0)	1 (2.2)	0.001*	0.007*
Co-infection, n (%)	12 (26.7)	8 (17.8)	0 (0.0)	0.311	<0.001*
Overall positive, n (%)	41 (91.1)	28 (62.2)	13 (28.9)	0.001*	<0.001*

Notes:

Method A: mNGS; Method B: Culture; Method C: Serological antibody test plus PCR.

The Chi-square test was utilized to calculate the difference between the two groups.

^*P < 0.05 was considered statistically significant.