Prevalence and impact of persistent symptoms following SARS-CoV-2 infection among healthcare workers: A cross-sectional survey in the SIREN cohort.

Introduction: Following SARS-CoV-2 infection, some patients experience a range of long-lasting symptoms, with a specific burden on their lives and ability to work.

Aim: We describe the prevalence and impact of persistent symptoms pre-/post-vaccination in SIREN study participants.

Methods: A cross-sectional study of SARS-CoV-2 positive participants was carried out within SIREN, a frequently tested UK healthcare worker cohort with vaccination and demographic data available. Participants with a SARS-CoV-2 positive PCR or anti-SARS-CoV-2 sample between 01 March 2020 and 31 September 2022 were asked via a questionnaire about symptoms and days absent from work following infection. Responses were excluded if infection dates were inconsistent with study records or missing key data. Symptom type/duration and whether infection occurred pre-/post-vaccination and during which variant period were described. Logistic regression was used to estimate factors associated with persistent symptoms (>12 weeks), adjusting for vaccination and demographic factors. The median days absent from work were also determined.

Results: Of 16,599 invitations, 6677 participants responded, and 5053 were included in the analysis. The prevalence of persistent symptoms (symptoms lasting over 12 weeks) differed by infection episode; highest for first infections (32.7%; 1557/4767) compared to second (21.6%; 214/991) and third infections (21.6%; 16/74). Most frequently reported symptoms were fatigue, tiredness, shortness of breath and difficulty concentrating. A higher prevalence of persistent symptoms was reported during the Wild-type variant period compared to the other variant periods (52.9% Wild-type vs. 20.7% Omicron, for any symptom reported during their first infection). Overall, persistent symptoms were higher among unvaccinated participants (unvaccinated 38.1% vs vaccinated 22.0%). Multivariable analysis showed that participants were less likely to report persistent symptoms in infections occurring after vaccination compared to those with an infection before vaccination in the Alpha/Delta and Omicron periods (Alpha/Delta: adjusted Odds Ratio (aOR) 0.66, CI 95% 0.51-0.87, p = aOR 0.07, CI 95% 0.01-0.65, p = 0.02). About half of participants reported that their persistent symptoms impacted their day-to-day (51.8%) and work-related (42.1%) activities 'a little', and 24.0% and 14.4% reported that the impact was 'A lot'. 8.9% reported they had reduced their working hours, and 13.9% had changed their working pattern.

Discussion: Persistent symptoms were frequent in our cohort, and there was a reduction in symptom duration in those with multiple infection episodes during later variant periods and post-vaccination. The impact of persistent symptoms resulting in reducing working hours or adjusting working patterns has important implications for workforce resilience. UK healthcare workers were highly exposed during the pandemic, demonstrating a significant burden.