Article in Japanese

Meningitis caused by non-typable Haemophilus influenzae in an otherwise healthy 4-year-old boy: a case study

Suguru TAKEUCHI, Naoko NISHIMURA, Hiromi HIBINO, Masahiro KAWAGUCHI, Fumihiko HATTORI, Kazuhiro HORIBA, Kensei GOTOH, Haruki HOSONO, Koji TAKEMOTO, Takao OZAKI

This study presents a case report of bacterial meningitis caused by non-typable Haemophilus influenzae (NTHi) in a 4-year-old boy with no medical history suggesting immunodeficiency. He had received one H. influenzae type b (Hib) vaccination at the age of 1 year and 4 months, but recently, presented with four days of persistent fever and headache, and was admitted to Konan Kosei Hospital. Physical examination revealed nuchal rigidity, and with elevated CRP, and predominantly polymorphonuclear pleocytosis in cerebrospinal fluid, bacterial meningitis was diagnosed, based on detection of an elevated leukocyte count. One day after admission, H. influenzae was isolated from cultures of a throat swab, blood and cerebrospinal fluid. Assessment of drug susceptibility showed that the isolated strain was beta-lactamase negative ampicillin-resistant. The patient recovered without sequelae after receiving intravenous ceftriaxone for 12 days. The isolated strain was judged to have an NT capsular serotype based on antiserum tests, but a small proportion of the bacteria being un-capsulated Hib could be a possibility. This research performed genetic testing by PCR and confirmed that the isolated strain was NTHi.
With low virulence, NTHi causing meningitis is considered rare in healthy children. However, there is suggestion that increased invasive infection from NTHi associates with adoption of the Hib vaccine, thus requiring caution with regard to future trends.

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Department of Pediatrics, Konan Kosei Hospital

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Received	November 21, 2014
Accepted	January 27, 2015

27 (1)：17─22,2015