Tomohiro Oishi1, Yoko Fukuda2, Shoko Wakabayashi3, Mina Kono4, Sahoko Ono5, Atsushi Kato6, Eisuke Kondo7, Yoshitaka Nakamura8, Yuhei Tanaka9, Hideto Teranishi10, Hiroto Akaike11, Takaaki Tanaka12, Ippei Miyata13, Satoko Ogita14, Naoki Ohno15, Takashi Nakano16, Kazunobu Ouchi17. 1. Department of Pediatrics, Kawasaki Medical School, 577, Matsushima, Kurashiki, Okayama, 701-0192, Japan. Electronic address: oo0612@med.kawasaki-m.ac.jp. 2. Department of Pediatrics, Kawasaki Medical School, 577, Matsushima, Kurashiki, Okayama, 701-0192, Japan. Electronic address: luminous105@yahoo.co.jp. 3. Department of Pediatrics, Kawasaki Medical School, 577, Matsushima, Kurashiki, Okayama, 701-0192, Japan. Electronic address: putrid-bunny.321@hyper.ocn.ne.jp. 4. Department of Pediatrics, Kawasaki Medical School, 577, Matsushima, Kurashiki, Okayama, 701-0192, Japan. Electronic address: mi.horiya@med.kawasaki-m.ac.jp. 5. Department of Pediatrics, Kawasaki Medical School, 577, Matsushima, Kurashiki, Okayama, 701-0192, Japan. Electronic address: m0105023@kwmed.jp. 6. Department of Pediatrics, Kawasaki Medical School, 577, Matsushima, Kurashiki, Okayama, 701-0192, Japan. Electronic address: katoatsu@med.kawasaki-m.ac.jp. 7. Department of Pediatrics, Kawasaki Medical School, 577, Matsushima, Kurashiki, Okayama, 701-0192, Japan. Electronic address: ekondo@med.kawasaki-m.ac.jp. 8. Department of Pediatrics, Kawasaki Medical School, 577, Matsushima, Kurashiki, Okayama, 701-0192, Japan; Nakano Children's Hospital, 4-13-17, Shinmori, Asahi-ku, Osaka, 535-0022, Japan; Iizuka Hospital, 3-83, Yoshiomachi, Iizuka, Fukuoka, 820-8505, Japan. Electronic address: ynakamura11@gmail.com. 9. Department of Pediatrics, Kawasaki Medical School, 577, Matsushima, Kurashiki, Okayama, 701-0192, Japan; Iizuka Hospital, 3-83, Yoshiomachi, Iizuka, Fukuoka, 820-8505, Japan. Electronic address: yuhei.tuk.first@gmail.com. 10. Department of Pediatrics, Kawasaki Medical School, 577, Matsushima, Kurashiki, Okayama, 701-0192, Japan. Electronic address: teranishi_0203@yahoo.co.jp. 11. Department of Pediatrics, Kawasaki Medical School, 577, Matsushima, Kurashiki, Okayama, 701-0192, Japan. Electronic address: redpond@med.kawasaki-m.ac.jp. 12. Department of Pediatrics, Kawasaki Medical School, 577, Matsushima, Kurashiki, Okayama, 701-0192, Japan. Electronic address: takaaki51@hotmail.com. 13. Department of Pediatrics, Kawasaki Medical School, 577, Matsushima, Kurashiki, Okayama, 701-0192, Japan. Electronic address: ippei@med.kawasaki-m.ac.jp. 14. Department of Pediatrics, Kawasaki Medical School, 577, Matsushima, Kurashiki, Okayama, 701-0192, Japan. Electronic address: ogita@med.kawasaki-m.ac.jp. 15. Department of Pediatrics, Kawasaki Medical School, 577, Matsushima, Kurashiki, Okayama, 701-0192, Japan. Electronic address: pdnaoki@hotmail.com. 16. Department of Pediatrics, Kawasaki Medical School, 577, Matsushima, Kurashiki, Okayama, 701-0192, Japan. Electronic address: nakano@med.kawasaki-m.ac.jp. 17. Department of Pediatrics, Kawasaki Medical School, 577, Matsushima, Kurashiki, Okayama, 701-0192, Japan. Electronic address: kouchi@med.kawasaki-m.ac.jp.
Abstract
OBJECTIVE: Chlamydia pneumoniae and Mycoplasma pneumoniae are both common causes of atypical pneumonia. We conducted an annual national survey of Japanese children to screen them for C. pneumoniae infections during the M. pneumoniae epidemic season. METHODS: Nasopharyngeal swab specimens were collected from children aged 0-15 years with suspected acute lower respiratory tract infection due to atypical pathogens, at 85 medical facilities in Japan from June 2008 to March 2018. Specimens were tested for infection using real-time polymerase chain reaction assays. RESULTS: Of 5002 specimens tested, 1822 (36.5%) were positive for M. pneumoniae alone, 42 (0.8%) were positive for C. pneumoniae alone, and 20 (0.4%) were positive for both organisms. In children with C. pneumoniae infection, the median C. pneumoniae DNA copy number was higher in those with single infections than in those with M. pneumoniae coinfection (p = 0.08); however it did not differ significantly according to whether the children had received antibiotics prior to sample collection (p = 0.34). CONCLUSIONS: The prevalence of C. pneumoniae infection was substantially lower than that of M. pneumoniae infection during the study period. The change in prevalence of C. pneumoniae was not influenced by that of M. pneumoniae. Children with single C. pneumoniae infection are likely to have had C. pneumoniae infection, while those with coinfection are likely to have been C. pneumoniae carriers.
OBJECTIVE:Chlamydia pneumoniae and Mycoplasma pneumoniae are both common causes of atypical pneumonia. We conducted an annual national survey of Japanese children to screen them for C. pneumoniae infections during the M. pneumoniae epidemic season. METHODS: Nasopharyngeal swab specimens were collected from children aged 0-15 years with suspected acute lower respiratory tract infection due to atypical pathogens, at 85 medical facilities in Japan from June 2008 to March 2018. Specimens were tested for infection using real-time polymerase chain reaction assays. RESULTS: Of 5002 specimens tested, 1822 (36.5%) were positive for M. pneumoniae alone, 42 (0.8%) were positive for C. pneumoniae alone, and 20 (0.4%) were positive for both organisms. In children with C. pneumoniae infection, the median C. pneumoniae DNA copy number was higher in those with single infections than in those with M. pneumoniae coinfection (p = 0.08); however it did not differ significantly according to whether the children had received antibiotics prior to sample collection (p = 0.34). CONCLUSIONS: The prevalence of C. pneumoniae infection was substantially lower than that of M. pneumoniae infection during the study period. The change in prevalence of C. pneumoniae was not influenced by that of M. pneumoniae. Children with single C. pneumoniae infection are likely to have had C. pneumoniae infection, while those with coinfection are likely to have been C. pneumoniae carriers.