Detection of Macrolide-Resistant Mycoplasma Pneumoniae in a Pediatric Primary and Secondary Emergency Care Center in Japan Following the COVID-19 Pandemic.

During the COVID-19 pandemic, Mycoplasma pneumoniae infections were rarely observed in Japan, but a significant outbreak occurred in 2024. At Oita Children's Hospital, a rapid quenching probe polymerase chain reaction (QP-PCR) method was employed to detect the pathogen and to determine the prevalence of macrolide resistance. Between April 1 and September 30, 2024, we tested 679 patients - 462 (68.0%) were positive and 399 (86.4%) were macrolide resistant. The resistance rate was among the highest reported in Japan and comparable to those in neighboring Asian countries. Inpatients were younger than outpatients, and their diagnoses required longer periods of time; corticosteroids were used in 86% of hospitalized cases. QP-PCR detects common A2063G and A2064G mutations and provides results within 40 minutes, which could promote timely therapy, and this is true particularly in the case of younger children, whose options could be limited. Early administration of effective antimicrobial agents is crucial for the control of macrolide-resistant M. pneumoniae. These findings indicate that QP-PCR-based diagnostics could significantly contribute to the management and control of M. pneumoniae outbreaks.