Factors Associated with SARS-CoV-2 Infection Among Healthcare Workers: A European Multicentre Cohort Study, May 2021–April 2024

Why It Matters

The study shows that non‑clinical staff and home environments drive a large share of HCW infections, reshaping occupational health priorities for future pandemics.

Key Takeaways

• Ancillary staff faced highest pre‑Omicron infection risk
• Household exposure increased infection odds fourfold pre‑Omicron
• Risk associated with role and home exposure declined over time
• Nurses and doctors showed lower hazard ratios than ancillary staff
• Prevention must extend beyond clinical personnel

Pulse Analysis

The longitudinal design of this European cohort provides a rare, granular view of how SARS‑CoV‑2 risk factors evolved among healthcare workers across three distinct pandemic phases. By enrolling over 4,700 staff members and coupling weekly questionnaires with regular PCR testing, the researchers could isolate the impact of occupational role, household exposure, and demographic variables while controlling for hospital‑level differences. This methodological rigor yields confidence that the observed hazard ratios reflect genuine transmission dynamics rather than reporting bias.

Early in the pandemic, ancillary personnel—often tasked with patient transport, cleaning, and logistical support—experienced a nearly four‑fold higher infection hazard compared with physicians. Simultaneously, a household contact raised infection odds by more than four times, underscoring the permeability of community transmission into clinical settings. As the Omicron wave unfolded and vaccination coverage expanded, both occupational and household risks diminished, suggesting that immunity, variant characteristics, and evolving infection‑control protocols collectively tempered exposure.

For hospital administrators and policymakers, the findings signal that infection‑prevention strategies must be fluid and inclusive. Relying solely on clinical staff vaccination or PPE distribution leaves a vulnerability gap among support workers who interact with patients and environments differently. Moreover, integrating community‑level safeguards—such as offering testing for household members or flexible sick‑leave policies—can blunt the spillover effect that fuels staff outbreaks. As health systems brace for future respiratory threats, the study advocates a holistic, data‑driven approach that continuously recalibrates protections based on real‑time risk assessments.