Surveillance of non-invasive group A Streptococcus infections in French ambulatory pediatrics before and during the COVID-19 pandemic: a prospective multicenter study from 2018 to 2022.

OBJECTIVES: We evaluated the burden of non-invasive group A Streptococcus (GAS) infections in ambulatory pediatrics before and during the COVID-19 pandemic in France.

METHODS: We analyzed data from a national network of ambulatory pediatricians between 2018 and 2022. Clinicians evaluating children ≤15 years old for tonsillopharyngitis, perianal infections, paronychia/blistering dactylitis and scarlet fever were invited to perform a rapid antigen detection test (RADT) for GAS. Monthly incidence of non-invasive GAS infections per 10,000 visits was modeled using time-series analysis, considering two breakpoints: March 2020 (first national lockdown) and March 2022 (end of mandatory mask-wearing in schools).

RESULTS: Over the study period, 125 pediatricians recorded 271,084 infectious episodes. GAS-related illnesses represented 4.3% of all infections. In March 2020, the incidence of GAS diseases decreased by 84.5% (p<0.001), with no significant trend until March 2022. After March 2022, the incidence significantly increased (+23.8% per month, p<0.001), with similar patterns across all monitored GAS-related diseases.

CONCLUSIONS: By using routine clinical data and RADTs, we have monitored changes in the incidence of non-invasive GAS infections in ambulatory pediatrics. COVID-19 mitigation measures have had a major impact on the epidemiology of non-invasive GAS infections, but their relaxation was followed by a surge above baseline levels.