Epidemiology and etiology of the first serogroup W135 meningococcal disease case in Hunan

Objective To understand the epidemiological and etiological characteristics of the first serogroup W135 meningococcal disease case in Hunan province. Methods Blood and cerebrospinal fluid specimens were collected from the suspected meningococcal disease case and throat swabs were collected from healthy people to isolate Neisseria meningitidis. Their identifications were conducted by serogrouping, multi locus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE). The strains' drug susceptibilities were tested. Results Serogroup W135 N. meningitidis was isolated from the cerebrospinal fluid and blood specimens of the suspected cases. Two strains of N. meningitidis W135 were isolated from the throat swabs of healthy people. Three W135 strains were ST-11 genotype, belonging to hyper invasive ST-11/ET-37 complex. All the N. meningitidis W135 strains showed resistance to sulfamethoxazole. Conclusion The first W135 meningococcal disease case was caused by ST-11 type strain, and the ST-11 type N. meningitis W135 were detected in healthy people, so N. meningitidis W135 might circulate in Hunan province.