This study is being done to learn more about enterovirus infections detected in the cerebrospinal fluid of patients at CHU de Brest. Researchers will analyze medical records and laboratory data collected between 2018 and 2024. They will look at how these infections present in patients, and whether a specific virus type, called Echo-9, may be associated with different clinical features or represent an emerging variant.

Inclusion Criteria:

• Cerebrospinal fluid (CSF) sample positive for enterovirus by RT-PCR between January 1, 2018 and December 31, 2024 , performed at the virology laboratory of CHU de Brest.
• No documented opposition to the use of medical data for research purposes.

Exclusion Criteria:

• Patients under legal protection (guardianship, curatorship, etc.)
• Refusal to participate in the study

Patients with a cerebrospinal fluid sample positive for enterovirus by RT-PCR performed at the virology laboratory of CHU de Brest between 2018 and 2024. This includes patients managed at CHU de Brest as well as at partner hospitals in Finistère (France) whose samples were processed centrally.

All collected data that underlie results in a publication

Data will be available beginning three years and ending fifteen years following the final study report completion

Data access requests will be reviewed by the internal committee of Brest UH. Requestors will be required to sign and complete a data access agreement