Incidence of childhood pneumonia and serotype and sequence-type distribution in Streptococcus pneumoniae isolates in Japan

• Published in: Epidemiology and infection Vol. 140; no. 6; pp. 1111 - 1121
• Main Authors: TANAKA, J., ISHIWADA, N., WADA, A., CHANG, B., HISHIKI, H., KUROSAKI, T., KOHNO, Y.
• Format: Journal Article
• Language: English
• Published: Cambridge, UK Cambridge University Press 01-06-2012
• Subjects: Adolescent; Anti-Bacterial Agents - pharmacology; Bacteriology; Biological and medical sciences; Blood; Child; Child, Preschool; Children; Drug Resistance, Multiple, Bacterial; Epidemiology; Fundamental and applied biological sciences. Psychology; Hospitalization; Humans; Incidence; Infant; Infectious diseases; Japan - epidemiology; Leukocytes; Microbiology; Miscellaneous; Pathogens; Pediatrics; Penicillin; Phylogeny; Pneumococcal pneumonia; Pneumonia; Pneumonia, Pneumococcal - epidemiology; Pneumonia, Pneumococcal - microbiology; Population; Respiratory infection; Sputum; Streptococcus infections; Streptococcus pneumoniae; Streptococcus pneumoniae - classification; Streptococcus pneumoniae - genetics; Vaccination; Vaccines; Asia; Japan; Far east; United States > US; Streptococcus pneumoniae (pneumococcus); immunization (vaccination); community-acquired pneumonia; incidence; Antibiotic resistance; Lung disease; Streptococcaceae; Pneumonia; Respiratory disease; Bacteria; Micrococcales; Isolate; Serotype; Epidemiology; Incidence; Streptococcus pneumoniae
• ISSN: 0950-2688; 1469-4409
• DOI: 10.1017/S0950268811001592

The 7-valent pneumococcal conjugate vaccine (PCV7) is reported to decrease the incidence of community-acquired pneumonia (CAP) in children. To determine the annual incidence of CAP before the introduction of PCV7, we counted the number of children hospitalized with CAP between 2008 and 2009 in Chiba City, Japan. We investigated serotype and multilocus sequence typing (MLST) for Streptococcus pneumoniae isolates in CAP cases. The annual incidence of hospitalized CAP in children aged <5 years was 17·6 episodes/1000 child-years. In 626 episodes, S. pneumoniae was dominant in 14·7% and 0·8% of sputum and blood samples, respectively. The most common serotypes were 6B, 23F and 19F. The coverage rates of PCV7 were 66·7% and 80% in sputum samples and blood samples, respectively. MLST analysis revealed 37 sequence types. Furthermore, 54·1% of the sputum isolates and 40% of the blood isolate were related to international multidrug-resistant clones.