Epidemiology and clinical impact of macrolide-resistant Mycoplasma pneumoniae in Singapore – findings from a multicentre surveillance programme

Mycoplasma pneumoniae is a leading cause of community-acquired pneumonia worldwide. Due to intrinsic beta-lactam resistance, macrolides are recommended as first-line treatment. However, macrolide-resistant M. pneumoniae (MRMP) has been increasingly reported globally, particularly in Asia, necessitating updated data to understand current trends. A time-limited paediatric surveillance programme was implemented in 2024 to elucidate the epidemiology and clinical impact of MRMP in Singapore. From Jan–Apr 2024, paediatric M. pneumoniae -positive samples from hospitals and the community acute respiratory infection (ARI) surveillance programme were tested at Singapore’s National Public Health Laboratory for genotypic macrolide resistance. Demographic, clinical, and epidemiological data were reviewed for hospitalised cases. Statistical analysis was performed to assess characteristics associated with macrolide resistance. A total of 412 M. pneumoniae cases (275 hospitalised and 137 community cases, aged 0–16 years) were successfully genotyped and included in the analysis. Of these, 16.7% (95% CI 12.5–21.7%) and 19.7% (95% CI 13.4–27.4%) of hospitalised and community cases, respectively, possessed the A2063G point mutation for macrolide resistance. No differences in age, ethnicity, comorbidities, symptomatology, presence of co-infections, care acuity, or mortality rate were detected between hospitalised MRMP and macrolide-susceptible M. pneumoniae cases. In adjusted analyses, MRMP cases had higher likelihood of recent overseas travel (OR 2.28, 95% CI 1.09–4.77), and longer duration of fever (mean difference 2.24 days, p < 0.01) and hospitalisation (mean difference 0.94 days, p = 0.01). All MRMP inpatients were discharged well. MRMP prevalence was 16.7% among hospitalised paediatric cases and 19.7% among community cases. MRMP was associated with longer fever duration and hospitalisation, but no other evidence of greater disease severity was observed. The findings do not indicate an immediate need to alter current local empirical treatment recommendations, although further research is needed to evaluate treatment effectiveness in MRMP. Periodic surveillance and responsible antimicrobial stewardship are crucial in mitigating rising resistance.