When Risk Persists: Two-Time Longitudinal Assessment of Healthcare Workers' Exposure Risk in the Context of COVID-19

Background: Healthcare workers (HCWs) have experienced sustained occupational exposure to SARS-CoV-2 throughout the COVID-19 pandemic. While infection prevention and control (IPC) practices have been widely implemented, limited prospective data exist on how occupational exposure risk and adherence to protective practices evolve over time, particularly beyond the acute phases of the pandemic. This study aimed to prospectively assess occupational and community exposure risk to COVID-19 among HCWs and to evaluate temporal changes in adherence to IPC practices during routine care and aerosol-generating procedures. Methods: A prospective observational study was conducted among HCWs from four public hospitals in the region of Thessaly, Greece. Eligible participants were HCWs who reported contact with suspected or confirmed COVID-19 cases. The data were collected at baseline (January-March 2022) and at a six-month follow-up using the World Health Organization's "Risk Assessment and Management of Exposure of Health Care Workers in the Context of COVID-19" questionnaire. The instrument captured demographic characteristics, professional roles, occupational and community exposure, and adherence to IPC practices. Results: A total of 203 HCWs participated in the study. The overall proportion of HCWs reporting occupational exposure was 72.9% in both assessments. Among HCWs with occupational exposure (n = 148), the proportion classified as high-risk showed a statistically significant increase from 76% (95% CI: 0.6951-0.8320) at baseline to 88% (95% CI: 0.8258-0.9310) at follow-up (p = 0.010). This shift reflects a substantial effect size, with the odds of high-risk classification being more than double at follow-up (OR = 2.24). Nurses consistently demonstrated higher risk compared with physicians. The overall use of personal protective equipment remained high. However, adherence to several IPC practices declined over time, including removal and replacement of PPE according to protocol and frequent decontamination of high-touch surfaces. Conclusions: Occupational exposure risk among HCWs remained substantial and increased over time despite stable occupational exposure estimates. The observed decline in adherence to key IPC measures highlights the need for continuous monitoring and reinforcement of protective practices in healthcare settings.