Following the alert issued during the second half of November 2022 regarding a higher-than-usual number of pediatric cases of IISGA, an initial assessment was conducted on December 8 based on available data and published on the Santé publique France website. In addition, active surveillance was immediately implemented by Santé publique France and the GFRUP (Francophone Group for Pediatric Intensive Care and Emergency Medicine) to strengthen the existing surveillance system, better assess the epidemiological situation, and characterize severe cases admitted to critical care units. We provide an update based on data as of December 18, 2022 (end of week 50) on the evolution of key epidemiological indicators.

Key Points

• Increase in pediatric cases of severe IISGA hospitalized in critical care units from September 1, 2022, through week 49; the majority of cases (66%) are linked to respiratory infections, with or without toxic shock syndrome. Data from week 50 suggest a decrease but have not yet been finalized. Of the 59 cases reported, 6 have died. Three additional deaths from IISGA prior to hospital admission have been reported.

• The incidence of scarlet fever in children continued to rise in week 50, according to emergency department visit data from the Oscour® network. However, in week 50, data on calls to SOS Médecins suggest a trend toward stabilization, though at a level that remains high. Data from outpatient pediatric care collected by the PARI network, meanwhile, suggest a downward trend in cases of strep throat and scarlet fever in week 50.

• The current epidemiological situation regarding AISGIs is not linked to the emergence of a new bacterial strain but primarily to two already known genotypes (emm12 and emm1).

• The resurgence of ARI could result, at least in part, from a post-restriction rebound among children whose immune systems have not been exposed to the strains of ARI that typically circulate. These infections are also frequently secondary infections following viral respiratory infections, which are also on the rise.