Metagenomic next-generation sequencing technology for detection of pathogens in blood of critically ill patients

Objective: To explore the applicability of metagenomic next-generation sequencing (mNGS) technology for the detection of blood pathogens in intensive care unit patients. Methods: The clinical data of 63 critically ill patients who could not be diagnosed with blood culture (BC) and who underwent mNGS blood sample testing were retrospectively analyzed. The diagnostic efficacy of mNGS was compared with that of traditional detection methods; the distribution of the pathogens identified by mNGS was analyzed; and the differences in laboratory tests, comorbidities, treatment, and prognosis between the mNGS-positive and mNGS-negative groups were compared. Results: The positive rate of mNGS was 41.3% (26/63), and 16 patients were found to have mixed infections. However, the positive rate of BCs performed simultaneously with mNGS was only 7.9% (5/63). The results of univariate analysis showed that the average length of intensive care unit stay (β, −8.689 [95% CI, −16.176, −1.202]; P = 0.026) and the time from onset to sequencing (β, −5.816 [95% CI,−9.936, −1.696]; P = 0.007) of the mNGS-positive group were significantly shorter than those of the mNGS-negative group. More patients in the positive group were adjusted for anti-infective treatment after mNGS (OR, 3.789 [95% CI,1.176, 12.211]; P < 0.001). Conclusions: Detection of blood pathogens by mNGS has good applicability for critically ill patients who cannot be diagnosed by BC in the early stages of infection, and mNGS should be performed as early as possible to obtain higher pathogen detection rates.