Reminder: Enterovirus Infections

Enteroviruses (EV) are found worldwide and circulate year-round in tropical regions. Located in a temperate zone, France experiences an annual increase in enterovirus infection diagnoses during the summer and fall, primarily linked to a resurgence of meningitis.

This increase can begin as early as May, with a summer peak usually observed in calendar weeks 26 or 27, often followed by a second, smaller peak during the fall.

Key Points

EV circulation at a particularly low level

In 2020 and during the first 5 months of 2021, the weekly number of cases remained well below that observed during the same period in 2018 and 2019. Emergency departments participating in the OSCOUR® surveillance system have not, to date, observed a significant increase in the number of emergency department visits for viral meningitis, although there was a possible upward trend during the first week of June (Week 22).

The surveillance system shows, in 2020, a stable, plateau-like epidemic curve, without a summer peak as observed in 2019—which saw an epidemic peak during week 27 (July 1–7)—or in previous years.

This situation, which continued throughout the first half of 2021, is very likely linked to the measures implemented to combat the COVID-19 epidemic and their continued enforcement, which has an effect on the transmission of other respiratory or enteric pathogens: preventive measures (handwashing, use of hand sanitizer, mask-wearing); physical distancing (social distancing, curfews, lockdowns, etc.).

Thus, the gradual lifting of lockdown measures and the risk of a relaxation in the application of preventive measures could lead to a resurgence of viral meningitis cases. Vigilance is therefore required in the event of any resurgence of viral meningitis cases.