The island of Reunion, a French overseas department of 860,000 inhabitants, located in the Indian Ocean (OI) zone, recorded its first case of COVID-19 on March 11, 2020. The epidemic, which was described as not very severe during the year 2020 in Reunion was much more intense and more deadly in 2021, with the arrival of the new variants (South African and Indian) and exploded at the beginning of the year 2022 (variant Omicron).

Reunion has a specific island context both climato-geographically and demographically. Indeed, this French island located in the southern hemisphere in the middle of the Indian Ocean (OI) has a tropical climate and a multi-ethnic population, younger than in mainland France (16% are over 60 years old). It is also marked by a higher prevalence in the general population of certain risk factors, such as obesity (11%) and type 2 diabetes (>10%), recognized as factors favoring severe clinical forms of COVID-19. as well as "persistent COVID-19".

This study will allow the constitution of a large-scale French cohort located in a closed overseas territory to provide answers to local specificities and to the management of the epidemic in the territory.

Inclusion Criteria:

• over 18 years old
• having been hospitalized at the University Hospital Center (CHU) of Reunion (minimum of one night in the hospital)
• with a positive diagnosis of COVID-19 (positive RT(reverse transcription)-PCR(Polymerase Chain Reaction) SARS-CoV-2 on a nasopharyngeal swab or positive serology or confirmed diagnosis in the medical file)
• registered in the COVIDEPI database
• whose telephone numbers are available in the computerized patient file
• residing on the island of Reunion
• knowing how to understand and speak French

Exclusion Criteria:

• deceased
• opposing the use of their data
• deprived of liberty by judicial or administrative decision, minors, and persons subject to a legal protection measure: guardianship or curators