Enteroviruses circulate worldwide. In temperate regions, such as France, hospital surveillance data show an annual increase in enterovirus infections during the summer and fall, primarily consisting of mild meningitis. This increase can be observed as early as May but most often occurs during the summer. The summer peak is usually observed in June/July, with a second, smaller peak during the fall. While most enterovirus infections cause few or no symptoms, certain infections can lead to severe complications, depending on age, immune status (deficiency in humoral immunity), or the type of enterovirus. For example, infections with EV-A71 or EV-D68 can be accompanied by severe neurological complications.

Enterovirus Activity Expected to Increase This Summer

The low circulation of enteroviruses (EV) observed in France since 2020, linked to measures to combat the COVID-19 pandemic, continued through 2022, with levels of EV-associated meningoencephalitis well below those observed between 2016 and 2019. Since 2022, a gradual resurgence in enterovirus circulation has been observed in France.

In 2024, the total number of EV infections reached 3,778 cases (compared to 2,339 cases in 2023), with the scale of the summer outbreak (2,151 cases) close to that of pre-COVID-19 years (an average of 2,720 cases between 2016 and 2019). The autumn peak in circulation was much more pronounced and occurred earlier than in previous years, linked to sustained circulation of EV-D68, without a resurgence of associated myelitis cases. In the summer, the meningitis outbreak—a neurological manifestation caused by enterovirus (EV) infections—was marked by a very short summer peak. The magnitude of this peak was similar to that observed in 2023 and during the years 2018–2019, with 2,151 reported cases, compared to 1,555 cases in 2023.

In 2025, the number of EV infection cases reported to the Enterovirus Surveillance Network (RSE) as of June 25, 2025, remains at a very low level compared to 2024, with a low number of meningitis cases relative to previous years (121 cases compared to 1,030 cases in 2024 for the first half of the year). This number is most likely underestimated due to the late start of the epidemic season (mid-June) and a delay in reporting EV infection cases by the RSE.

In contrast, the number of emergency department visits and hospitalizations for viral meningitis reported by the OSCOUR network appears to have been increasing since the last week of May, though at a level lower than in 2024 but similar to pre-COVID-19 years. This could indicate an expected summer peak in the coming weeks.
Vigilance therefore remains essential throughout the summer of 2025 given the current resurgence of EV infections and viral meningitis, particularly among very young children.

What are the recommendations for healthcare professionals?

Given the current increase in enterovirus circulation, Santé publique France and the National Reference Center for Enteroviruses and Parechoviruses urge healthcare professionals to exercise particular vigilance in cases of severe clinical presentations, especially neurological ones, or in immunocompromised individuals, and in cases of severe neonatal infection, where enterovirus infection must be considered and investigated.

They emphasize the importance of collecting appropriate specimens for EV genome testing (CSF, blood, nasopharyngeal swabs, stool) in all cases of severe clinical presentation. Accordingly, any neonatal infection or severe neurological condition associated with an EV infection must be reported to the CNR, and samples must be sent to complete virological investigations (including sequencing).