Early Identification of Pathogens in Children With Respiratory Tract Infection by Mechanical Ventilation Using mNGS

This study is an observational study to evaluate the accuracy of pathogens in children with VAP tested by mNGS with no intervention. All patients from the cohort accept mNGS test and bacterial culture or virus PCR detection. A double sputum specimens are used for test.The reference standard is bacterial culture or virus PCR detection.