-Original-

The Incidence of Pediatric Invasive Bacterial Diseases in Nippon Medical School Chiba Hokusoh Hospital before and after the Introduction of Conjugate Vaccines

Toumi Sano¹, Tamaho Suzuki¹, Ayako Nishigori¹, Chiharu Miyatake¹, Shinya Koizumi¹, Kiyohiko Kaizu¹, Atsushi Fujita¹, Mitsuhiro Kamisago¹, Bin Chang², Naruhiko Ishiwada³ and Takeshi Asano¹

¹Department of Pediatrics, Nippon Medical School Chiba Hokusoh Hospital, Chiba, Japan
²Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan
³Department of Infectious Diseases, Medical Mycology Research Center, Chiba University, Chiba, Japan

The introduction of the Haemophilus influenzae type b (Hib) vaccine and the 7-valent pneumococcal conjugate vaccine (PCV7) has led to dramatic reductions in cases of invasive H. influenzae disease and invasive pneumococcal disease (IPD). After the introduction of the PCV7 and the 13-valent pneumococcal conjugate vaccine (PCV13), the number of children with IPD markedly decreased in our hospital. However, since 2015, three children with IPD have been admitted to our hospital. We analyzed the serotype, multilocus sequence type, and antimicrobial susceptibility of Streptococcus pneumoniae strains isolated in these newly diagnosed cases. The strains were serotypes 7F and 12F. In addition, we analyzed the incidence of invasive bacterial disease before and after the introduction of conjugate vaccines and found no change in the incidences. We found that cases of IPD and invasive H. influenzae disease clearly decreased following the introduction of the PCV7, the PCV13, and the Hib vaccine, as well as disease caused by antibiotic-resistant strains.

J Nippon Med Sch 2018; 85: 34-38

Keywords
Streptococcus pneumoniae, Haemophilus influenzae, conjugate vaccine

Correspondence to
Takeshi Asano, MD, Department of Pediatrics, Nippon Medical School Chiba Hokusoh Hospital, 1715 Kamagari, Inzai, Chiba 270-1694, Japan
july1364@nms.ac.jp

Received, August 1, 2017
Accepted, November 1, 2017