Background: The impact of the coronavirus disease 2019 (COVID-19) pandemic on people with multiple sclerosis (MS) is a major current concern, in particular the risk of death . Here we describe the impact of the first wave of COVID-19 infections (Mar 2020-July 2020) on the Scottish MS Register (SMSR) population, a cohort of 4702 individuals with MS, all newly diagnosed in the past decade.Methods: We established a clinician alert system, linking the SMSR with the Electronic Communication of Surveillance in Scotland (ECOSS). This allows identification of patients within this cohort who had a positive SARS-CoV-2 PCR test . The SMSR was also linked to death records from National Records Scotland.

Results: Of 4702 people with MS, 246 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) PCR tests were performed, of which 17 were positive . The proportion of positive tests were similar to the general Scotland population (Observed PCR confirmed cases = 17, expected = 17.5, O/E = 0.97 , 95% CI : 0.60 – 1.56, p=.90). Between 1 st March – 31 st July 2020 12 individuals on the SMSR died , 5 of which were linked to COVID-19 (1 PCR confirmed , 4 clinical diagnoses without PCR confirmation). This number of COVID-19-related deaths was higher than expected (observed deaths = 5, expected deaths = 1.2, O/E = 4.03 , 95% CI = 1.48 – 8.94, p=.01). All COVID-19-related deaths in the SMSR occurred in individuals with advanced disability (Expanded Disability Status Scale ≥7), and no deaths occurred in patients receiving disease modifying therapy (DMT) therapies.Conclusion: In this nationally comprehensive cohort of MS patients diagnosed in Scotland within the past 10 years, we observed similar rates of PCR-confirmed SARS-CoV-2 infection compared to the general Scottish population, but a small number of excess COVID-19 related deaths . These deaths occurred in individuals with advanced disability who were not receiving DMTs.