title: Recent trends in pediatric bacterial meningitis in Japan--a country where Haemophilus influenzae type b and Streptococcus pneumoniae conjugated vaccines have just been introduced.
abstract: To investigate the trends in incidence and the characteristics of bacterial meningitis in Japan where Haemophilus influenzae type b (Hib) vaccine and 7-valent pneumococcal conjugated vaccine (PCV7) were introduced in 2008 and 2010, respectively, which was 5-20 years after their introduction in western countries. The nationwide Japanese survey of pediatric and neonatal bacterial meningitis was performed in 2011 and 2012. We analyzed the epidemiological and clinical data, and compared the information obtained in the previous nationwide survey database. We also investigated the risk factors for disease outcome. In the 2011-2012 surveys, 357 patients were evaluated. H. influenzae, Streptococcus pneumoniae, Streptococcus agalactiae and Escherichia coli were the main organisms. The number of patients hospitalized with bacterial meningitis per 1000 admissions decreased from 1.31 in 2009 to 0.43 in 2012 (p < 0.001). The incidence of H. influenzae and S. pneumoniae meningitis also decreased from 0.66 to 0.08 (p < 0.001), and 0.30 to 0.06 (p < 0.001), respectively. Only 0-2 cases with Neisseria meningitidis were reported each year throughout 2001-2012. The median patient age was 10-12 months in 2001-2011, and became lower in 2012 (2 month old) (p < 0.001). The fatality rate for S. agalactiae is the highest (5.9% (11/187)) throughout 2001-2012 among the four organisms. Risk factors for death and sequelae were convulsions at onset, low CSF glucose, S. agalactiae etiology, and persistent positive CSF culture. Hib vaccine and PCV7 decreased the rate of bacterial meningitis. Earlier introduction of these vaccines may have prevented bacterial meningitis among Japanese children.
authors.affiliation: Department of Pediatrics, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan; Center for Infectious Diseases and Infection Control, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan. Electronic address: m-shinjo@z2.keio.jp.
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Shinjoh
authors.affiliation: Center for Infectious Diseases and Infection Control, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan; Department of Infectious Diseases, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Iwata
authors.affiliation: Department of Pediatrics, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
authors.forename: Tatsuhiko
authors.initials: T
authors.lastname: Yagihashi
authors.affiliation: Department of Pediatrics, Fuji Heavy Industries Health Insurance Society Ota Memorial Hospital, 455-1 Oshima-cho, Ota, Gunma 373-8585, Japan.
authors.forename: Yoshitake
authors.initials: Y
authors.lastname: Sato
authors.affiliation: Department of Pediatrics, St. Marianna University School of Medicine, Yokohama City Seibu Hospital, 1197-1 Yasashi-cho, Asahi-ku, Yokohama 241-0811, Japan.
authors.forename: Hironobu
authors.initials: H
authors.lastname: Akita
authors.affiliation: Department of Pediatrics, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
authors.forename: Takao
authors.initials: T
authors.lastname: Takahashi
authors.affiliation: Kitasato University, Research Organization for Infection Control Sciences, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Sunakawa
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D016667:Bacterial Capsules; D003430:Cross-Sectional Studies; D005260:Female; D006192:Haemophilus Infections / Q000453:epidemiology / Q000382:microbiology; D018073:Haemophilus Vaccines; D019741:Haemophilus influenzae type b / Q000187:drug effects / Q000302:isolation & purification; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D006760:Hospitalization; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D007564:Japan / Q000453:epidemiology; D008297:Male; D016920:Meningitis, Bacterial / Q000453:epidemiology / Q000382:microbiology; D022242:Pneumococcal Vaccines; D012307:Risk Factors; D013290:Streptococcal Infections / Q000453:epidemiology / Q000382:microbiology; D013296:Streptococcus pneumoniae / Q000187:drug effects / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents; D018073:Haemophilus Vaccines; C044237:Haemophilus influenzae type b polysaccharide vaccine; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D022242:Pneumococcal Vaccines
keywords: Bacterial meningitis; Children; Hib; PCV