Mycoplasma pneumoniae in pediatric patients: Do macrolide-resistance and/or delayed treatment matter?

Background: Mycoplasma pneumoniae is a common pathogen for pneumonia in children, especially in the post-pneumococcal conjugate vaccination era. Though self-limited disease was found in the majority of the patients, severe diseases occurred occasionally. The emergence of macrolide resistance was reported worldwide. It is important to delineate whether macrolide resistance or delayed treatment affects outcome.

Methods: We retrospectively collected pediatric patients with M. pneumoniae infection confirmed by positive PCR in a tertiary medical center in Taiwan from 2010 to 2017. Patients' clinical characteristics, bacterial load, macrolide resistance and treatment outcome were analyzed.

Results: Among 471 children with positive M. pneumoniae PCR, 95% were diagnosed with pneumonia. Seventeen percent of patients had extrapulmonary complications, and 1.5% had respiratory failure. Delayed treatment was associated with prolonged fever after appropriate treatment, fulminant disease, and extrapulmonary manifestations (p < 0.05). The mean rate of macrolide resistance was 24% and macrolide resistance was related to longer febrile duration, longer hospital stay, lung consolidation and impaired liver function tests (P < 0.05).

Conclusions: Macrolide resistance was fairly common and might lead to delayed appropriate antibiotic treatment. Delayed appropriate antimicrobial treatment, no matter macrolide resistance or not, was associated with more severe and/or prolonged diseases. Early diagnosis of M. pneumoniae as well as the awareness of macrolide resistance make early effective antibiotic treatment possible and may improve clinical outcomes.