OBJECTIVE To explore the diagnostic efficacy of metagenomic next-generation sequencing (mNGS) in the etiology of central nervous system (CNS) infection.

METHODS A total of 73 inpatients admitted to Wenzhou Central Hospital between Jun. 2022 and Jan. 2025 with suspected CNS infection were consecutively included. Cerebrospinal fluid was collected and tested for both mNGS and traditional culture. Based on the clinical diagnosis of CNS infection, the sensitivity, specificity, positive predictive value, negative predictive value and Youden′s index of the two methods were compared. The diagnostic efficacy of mNGS and traditional culture was evaluated with the receiver operating characteristic (ROC) curves.

RESULTS Ultimately, 41 patients were clinically confirmed with CNS infection. mNGS (DNA) yielded positive results in 36 cases, there were 11 cases of simple bacterial infection with only 1 species, 4 cases of simple viral (DNA) infection with only 1 species, and 21 cases of mixed infections with no less than 2 species of pathogens. The types of mixed infections and the number of cases were as follows: 4 cases of simple bacterial infections with more than 2 species, 6 cases of simple viral (DNA) infections with more than 2 types, 4 cases of mixed infections with bacteria and viruses (DNA), 1 case of mixed infections with bacterial and fungi, 5 cases of mixed infections with viruses and fungi, and 1 case of mixed infection with bacteria, viruses (DNA) and fungi. Traditional culture detected positive results in 8 cases, including 6 cases of bacterial infection and 2 cases of fungal infection. The sensitivity, specificity, positive predictive value, negative predictive value and Youden′s index of mNGS were 0.878, 0.719, 0.800, 0.821 and 0.597, respectively. The sensitivity, specificity, positive predictive value, negative predictive value and Youden′s index of traditional culture were 0.195, 0.969, 0.888, 0.484 and 0.164, respectively. The positive rate of mNGS was higher than that of traditional culture (χ²=29.000, P < 0.001), and the positive detection rate was also higher (χ²=4.690, P=0.030). The ROC curve showed that the area under the curve (AUC) for mNGS in diagnosing CNS infection was 0.790, whereas it was 0.573 for traditional culture.

CONCLUSION Cerebrospinal fluid mNGS can effectively improve the detection of pathogens causing CNS infection, with diagnostic efficacy superior to traditional culture, and can serve as a necessary supplement to traditional diagnostic techniques.