OBJECTIVES

To evaluate the trend in macrolide ambulatory use among children in Switzerland following a global surge in infections in late 2023.

METHODS

We conducted a population-based interrupted time-series analysis of macrolide use in Swiss children aged 0 to 11 years from 2018 to 2023 using national ambulatory antibiotic claims data. The main outcome was the evolution of macrolide use in ambulatory setting, expressed as monthly defined daily doses (DDD) per 1000 children. We defined two time periods: (i) the pre-autumn 2023 period, before detections increased in Switzerland (1 January 2018 to 30 September 2023) and (ii) the autumn 2023 period, after detections increased in Switzerland (1 October 2023 to 31 December 2023). We built a quasi-Poisson regression model to estimate the changes in macrolide monthly DDD per 1000 children from October 2023 in Switzerland. The model accounted for temporal trends before the WHO alert and for the seasonal pattern of macrolide prescriptions. We analysed amoxicillin use as a control outcome.

RESULTS

We found a significant increase in macrolides use expressed in monthly DDD per 1000 children aged 0 to 11 years from October 2023 in Switzerland [+235% (95%CI +139%-+368%), value < 0.001]. The use of amoxicillin remained stable in both age groups after October 2023.

CONCLUSIONS

We found a 3-fold increase in macrolide monthly DDD per 1000 children in autumn 2023 in the context of a global increase in infections. Monitoring macrolide resistance and promoting appropriate prescription practices are essential.