Influenza vaccination among healthcare workers and absenteeism from work due to influenza-like illness in a teaching hospital in Palermo

Background: Annual flu vaccination of healthcare workers (HCWs) is recommended worldwide as the best way to prevent influenza and to avoid its transmission. However, in several European Countries, vaccination rate among HCWs is still less than 25%. The aim of this study was to determine the HCW vaccination coverage during a three year period in a large University Hospital, identifying socio- demographic and occupational variables involved in the decision to accept influenza vaccination. Moreover, for the 2007-2008 season, we also assessed the effectiveness of influenza vaccination in reducing influenza-related absenteeism. Methods: During three consecutive influenza seasons (from 2005-2006 to 2007-2008), a cross-sectional study was carried out on all HCWs employed in the "Azienda Ospedaliera Universitaria Policlinico" (AOUP) of Palermo (Italy). Socio-demographic and occupational data of HCWs were collected from administrative hospital personnel records and included gender, age, birthplace, residence, profession and the workplace unit. In addition, during the 2007-2008 season, a retrospective study was conducted to evaluate absence from work due to influenza-like illness (ILI) in vaccinated versus unvaccinated personnel. Results: A total of 7,848 HCW-years were observed and 881 vaccines were administered during the study period. Vaccination rate declined from 14.7%in2005- 2006 to 8.2% in 2007-2008 (Chi-square for trend= 53.6, p< 0.001). Coverage was generally higher among older and male HCWs whereas nurses and workers in surgical areas had lower vaccination rates. In the 2007-2008 season, absenteeism due to ILI in the vaccinated group was significantly less common than unvaccinated HCWs (3.3% vs 7.1%; p= 0.04). Conclusions: Our experience encourages flu vaccination of HCWs and accentuates the importance of annual influenza vaccination programs for healthcare personnel.