Flu and other Acute Respiratory Infections in the Working Population. The Impact of Influenza A (H1N1) Epidemic

Abstract Introduction This study aims to asses the impact of influenza and other acute respiratory infectious diseases (ARI) on the Catalan working population between January 2007 and December 2009, including the period of the influenza virus A (H1N1) pandemic in our region. Methods All certified sickness absence episodes (sick-leave) due to influenza and other ARI amongst the working population of Catalonia, Spain, were analyzed from January 2007 to December 2009. Monthly and weekly incidence was calculated, as well as an influenza sick-leave threshold, in order to identify the epidemic season in the working population. Results Registered annual sick-leave incidence for influenza-like illnesses (ILI) per 100 000 workers was 1260.6 in 2007, 915.2 in 2008 and 2377.2 in 2009. Epidemic curves show monthly peaks in January- February each year, plus a second peak in November 2009 corresponding to the influenza virus A (H1N1) pandemic in our region. In 2009 sick-leave incidence for ILI and other ARI was higher in workers from the Health-Social Services sector than in the other workers ( P Conclusion This study contributes to understanding the impact of influenza and other ARI on the general workforce, during a period of time including the outbreak of influenza virus A (H1N1).