Article in Japanese

A case of meningitis caused by Neisseria meningitidis type B in a 13-year-old girl presenting with rapidly progressive headache

Takayuki Handa^1）, Yoichi Haga^1）, Yuki Nishihara^1）, Hiroyuki Takahashi^1）, Shinichi Takatsuki^1）

Cases of invasive meningococcal disease （IMD） significantly decreased after the COVID-19 pandemic in Japan. This study reports such a case in a previously healthy 13-year-old girl who developed sore throat, chills, and fever two days before presentation, followed by headache and frequent vomiting starting 12 h before hospital admission. Initial evaluation revealed meningeal irritation, and a cerebrospinal fluid test suggested bacterial meningitis. Neisseria meningitidis was identified in cerebrospinal fluid culture, and the patient was diagnosed with IMD. Serogroups Y/W-135 （latex agglutination） and B （PCR） were confirmed. The infection source remained undetermined. Antimicrobial therapy with ampicillin and ceftriaxone resolved the fever by day three, and the patient was discharged after a 14-day course of antibiotics, without neurological complications. Although IMD prevalence in Japan declined in 2020, the number of patients with this disease increased since resurgence of COVID-19 in 2023. The IMD trend may correlate with human behavioral changes during the COVID-19 pandemic and the increase in international travelers. Therefore, meningococcal vaccines targeting serogroup B are warranted to prevent the spread of IMD.

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1）Department of Pediatrics, Toho University Omori Medical Center

Key words	Neisseria meningitidis, invasive meningococcal disease, vaccine, serotypeB, inbound
Received	July 15, 2025
Accepted	March 12, 2026

38 (2)：157─163,2026