Diagnostic Performance of Metagenomic Next-Generation Sequencing in Pediatric Patients: A Retrospective Study in a Large Children’s Medical Center

BACKGROUND: Metagenomic next-generation sequencing (mNGS) has the potential to become a complementary, if not essential, test in some clinical settings. However, the clinical application of mNGS in a large population of children with various types of infectious diseases (IDs) has not been previously evaluated. METHODS: From April 2019 to April 2021, 640 samples were collected at a single pediatric hospital and classified as ID [479 (74.8%)], non-ID [NID; 156 (24.4%)], and unknown cases [5 (0.8%)], according to the final clinical diagnosis. We compared the diagnostic performance in pathogen detection between mNGS and standard reference tests. RESULTS: According to final clinical diagnosis, the sensitivity and specificity of mNGS were 75.0% (95% CI: 70.8%-79.2%) and 59.0% (95% CI: 51.3%-66.7%), respectively. For distinguishing ID from NID, the sensitivity of mNGS was approximately 45.0% higher than that of standard tests (75.0% vs 30.0%; P < 0.001). For fungal detection, mNGS showed positive results in 93.0% of cases, compared to 43.7% for standard tests (P < 0.001). Diagnostic information was increased in respiratory system samples through the addition of meta-transcriptomic sequencing. Further analysis also showed that the read counts in sequencing data were highly correlated with clinical diagnosis, regardless of whether infection was by single or multiple pathogens (Kendall's tau b = 0.484, P < 0.001). CONCLUSIONS: For pediatric patients in critical condition with suspected infection, mNGS tests can provide valuable diagnostic information to resolve negative or inconclusive routine test results, differentiate ID from NID cases, and facilitate accurate and effective clinical therapeutic decision-making.