About the Authors

Shigeo Hanada

Affiliations Department of Respiratory Medicine, Respiratory Center, Toranomon Hospital, Tokyo, Japan, Department of Infectious Diseases, Keio University School of Medicine, Tokyo, Japan, Okinaka Memorial Institute for Medical Research, Tokyo, Japan

Satoshi Iwata

Affiliation Department of Infectious Diseases, Keio University School of Medicine, Tokyo, Japan

Kazuma Kishi

Affiliations Department of Respiratory Medicine, Respiratory Center, Toranomon Hospital, Tokyo, Japan, Okinaka Memorial Institute for Medical Research, Tokyo, Japan

Miyuki Morozumi

Affiliation Department of Infectious Diseases, Keio University School of Medicine, Tokyo, Japan

Naoko Chiba

Affiliation Department of Infectious Diseases, Keio University School of Medicine, Tokyo, Japan

Takeaki Wajima

Affiliation Department of Microbiology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan

Misako Takata

Affiliation Department of Infectious Diseases, Keio University School of Medicine, Tokyo, Japan

Kimiko Ubukata

ubukatak@keio.jp

Affiliation Department of Infectious Diseases, Keio University School of Medicine, Tokyo, Japan

The Invasive Pneumococcal Diseases Surveillance Study Group

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: SH SI KU. Performed the experiments: NC MM TW MT. Analyzed the data: SH SI KU KK. Contributed reagents/materials/analysis tools: NC MM TW. Wrote the paper: SH KU.