Objective:To analyze the epidemiological and etiological characteristics of a death case of meningococcal meningitis in Hengyang city, Hunan Province in 2024.Methods:Epidemiological investigation of the death case was performed, and samples from the patient and close contacts were collected. Following cultivation and isolation, Neisseria meningitidis ( Nm) strains were analyzed by antimicrobial susceptibility testing, pulsed field gel electrophoresis (PFGE), and whole-genome sequencing for analyzing epidemiological and etiological characteristics. Phylogenetic analysis was carried out using core genomic multilocus sequence typing (cgMLST). Results:The case was a 16-year-old high school boarding student with fulminant meningococcal meningitis. He had shock symptoms, and died within 24 h of the onset of symptoms. Six Nm strains were isolated from the patient and his roommates, belonging to two distinct clades. Isolate 144569 from the patient was highly homologous to isolate 144572 from a close contact, both belonging to the highly pathogenic sublineage L44.1 of CC4821. The typical molecular features was C: P1.7-2, 14: F5-101: ST4821 (CC4821). The two strains carried the antimicrobial resistance genes of gyrA-71 and penA-552, indicating reduced susceptibility to quinolone and penicillin, which was with their resistance phenotype. The isolates from four close contacts clustered within the same clade, characterized by the molecular features of B: P1.18-25, 9-18: ST5829 (UA). Conclusions:The death case is caused by Nm serogroup C from highly pathogenic sublineage L44.1 of CC4821. The spread of this isolate has the potential risk of outbreaks of invasive meningococcal disease. It is necessary to enhanced the molecular epidemiological surveillance, particularly focusing on the transmission of multiple serogroups of Nm among adolescents and the increasing exposure risk.