Key Points

2023 Year in Review

• Return of enterovirus circulation to pre-COVID-19 levels (n=2,339 infections).

• Summer outbreak of EV meningitis (n=1,555) of moderate magnitude but larger than in 2022. The predominant types were echovirus 9 (E9), E18, and coxsackievirus B5 (CVB5).

• Stability in neonatal infections: n=442 cases, representing 19% of EV infections, compared to 444 cases (26% of EV infections) in 2022. An alert in April 2023 concerned severe early neonatal infections with liver failure linked to a new recombinant variant of E11, which resulted in the deaths of 7 newborns between July 2022 and March 2023. In total, for the year 2023, 4 severe infections with multi-organ failure associated with E11 (including one death) were identified. The circulation of E11 observed in the first half of 2023 (n=25/293 typed) gave way to E18 (n=72/293 typed), followed by E9.

• Resurgence of EV-A71 infections (third most common type, n=130 [vs. 22 in 2022]), associated with severe neurological disorders such as (rhomb)encephalitis, encephalomyelitis, and cerebellitis, particularly in children under 5 years of age.

• Low circulation of EV-D68 (n=67 cases detected vs. 139 in 2022).

• Detection of a type 3 vaccine-derived poliovirus (iVDPV-3) in a 15-month-old immunocompromised child who had received 4 doses of oral polio vaccine in their country of origin. No transmission around the case was detected.

• Point specific to the French overseas departments and communities (DROM-COM): Implementation of environmental wastewater surveillance during the period of drinking water shortage in Mayotte, which enabled the detection of the poliovirus vaccine strain 2 contained in the new oral vaccine (nOPV2) in 1 out of 25 samples collected in 2023.

Epidemiological situation as of June 19, 2024

• Resurgence of enterovirus meningitis marked by earlier circulation than in previous years and the onset of a summer epidemic that appears to be of similar magnitude to 2023:

  • patients over 15 years of age are the most affected (32% in 2024 compared to 23% in 2023 and 18% in 2022);

  • E30, followed by E6 and CVB3, are the most frequently identified EV types.

• Neonatal infections: n=105 cases (16% of CV infections), including 8 severe infections that led to 2 deaths. Different types of coxsackievirus B were identified in 7 newborns.

• Low circulation of EV-A71 and EV-D68.