Seroprevalence of SARS-CoV-2 antibodies in a prospective cohort of patients admitted to an acute psychiatric ward in Norway during the initial months of the COVID-19 pandemic.

Background: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that causes coronavirus disease 2019 (COVID-19) spread around the world during the first part of 2020. The purpose of the study was to assess the prevalence of SARS-CoV-2 infection among patients acutely admitted to the Psychiatric Clinic, Haukeland University Hospital.

Methods: Serum tests to assess for antibodies to SARS-CoV-2 were administered at admission to the clinic together with a questionnaire on symptoms and demographical information. Further information was obtained from the medical records.

Results: The cumulative seroprevalence in the 266 participants was 0.75%, the cumulative reported cases in the Norwegian general population was 0.61% at the end of the inclusion period of the study. Twenty-five percent of participants had risk factors for a serious course of COVID-19. There was a low prevalence of cohabitation and only 20% had their main income derived from ordinary salaries (not welfare).

Conclusion: The prevalence of SARS-CoV-2 infection in a sample of patients acutely admitted to the Psychiatric Clinic, Haukeland University Hospital, was comparable to reported cases in the general population. A possible link to governmental and municipal restrictions, general low workplace participation and cohabitation is discussed.