Article in Japanese

Mycoplasma pneumoniae infection in pediatric inpatients over a ten year period

Tomoki INOUE¹⁾, Tomohiro OISHI¹⁾, Kento TAKAHASHI¹⁾, Shoko WAKABAYASHI¹⁾, Mina KONO¹⁾, Atsushi KATO¹⁾, Hiroto AKAIKE¹⁾, Takaaki TANAKA²⁾, Ippei MIYATA¹⁾, Naoki OHNO¹⁾, Takashi NAKANO²⁾, Kazunobu OUCHI¹⁾

The prevalence of Mycoplasma pneumoniae (MP) infection, which is one of the major pathogens of community-acquired pneumonia, increased throughout Japan in 2011, 2012, 2015, and 2016. The rate of macrolide-resistant MP (MRMP) also increased. We have previously examined this epidemic situation among Japanese children. However, as yet, there have been no reports conducted on pediatric inpatients with MP infection.
In total, 114 children aged <15 years with a lower respiratory infection due to MP, who were admitted to Kawasaki Medical Hospital between January 2010 and December 2019, were enrolled. The MP strain was detected from a nasopharyngeal swab using real-time polymerase chain reaction. Furthermore, gene mutations resistant to macrolide agents and the patients' backgrounds were examined.
The annual number and annual rate of MRMP changed concurrently with the MP epidemic. Among infants, the rate of inpatients with bronchial asthma, desaturation, and undergoing steroidal treatment was significantly higher than that for school-age children. Among school-age children, the rate of moderate and heavy grade pneumonia shadows on the chest radiographs was significantly higher than that for pre-school-age children. The rate of moderate and heavy grade pneumonia shadows on chest radiographs was also higher among those with macrolide-resistant MP than those with macrolide-susceptible MP.
In conclusion, bronchial asthma complications or desaturation among infants, moderate and heavy grade pneumonia shadows on chest radiographs among school-age children, and MRMP were the important factors for admission of pediatric patients for MP infection.

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1) Department of Pediatrics, Kawasaki Medical School
2) Department of Pediatrics, Kawasaki Medical School General Medical Center

Key words	Mycoplasma, children, hospitalization
Received	May 21, 2020
Accepted	November 9, 2020

32 (4)：345─351,2020