A seroconversion test for SARS-Cov-2 will be offered to all the employees of a care institution, which has treated 240 patients hospitalized for COVID disease between 28/02 and 30/04/2020. The seroconversion test will be with a questionnaire to determine:

• whether the subject has shown signs of infection in the last 3 recent months
• if the subject has been in contact with COVID-diagnosed subjects (RT-PCR diagnosis or scanner) outside of the activity or within the professional activity (patient or colleague)
• Working conditions during the period
• The level of knowledge and respect of the barrier measures practices.
• Respect for distance during meals professional. Overall seroprevalence and stratified seroprevalence by care and administrative areas will be determined.

Inclusion Criteria:

• Subject who worked at Saint Joseph Saint Luke's Hospital during the epidemic wave (male or female).

  • Free and informed consent
  • Social security affiliation

Exclusion Criteria:

• Subject refusal
• Subject on leave during the entire period