Abstract Background: Pertussis vaccination coverage remains unsatisfactory in adults in France and pertussis is the leading cause of death due to bacterial infection in infants up to 3 months of age, whom are most often infected by parents and siblings. The objective of this study is therefore to evaluate the epidemiologic trends in the number of cases of pertussis requiring hospitalisation and the associated costs in France between 2006 and 2012. Methods: We performed a cross-sectional, retrospective analysis of hospitalisations with a diagnosis of pertussis in France between 2006 and 2012 by means of the French diagnosis related group national program database. The initial and subsequent stays for pertussis were identified for each patient over the 7-year period. Results: A peak in the number of pertussis cases requiring hospitalisation was observed in 2009 and an even larger peak was observed in 2012. Infants under the age of 3 months had the greatest number of hospitalisations, the longest and most costly stays and the highest proportion with composite markers of severity, followed by adults aged 50 and older. Patient stays ending in death were most frequent in adults aged 50 years and older (1.4%), followed by infants under 3 months of age (0.6%), with a total of 0.6% for all ages. The mean annual crude hospitalisation rate was 1.6 per 100,000, all ages combined, and infants aged less than 3 months had a far greater 48.8 per 100,000 rate. Conclusions: This study confirms the cyclic epidemiological trends of pertussis and show two marked peaks in 2009 and 2012 of cases requiring hospitalisations in France. Infants are at the highest risk for hospitalisations and the most severe cases, followed by adults aged 50 years and older. Despite a vaccination program for infants and young parents and siblings, the burden of pertussis remains high.
Keywords: hospitalisations; pertussis; whooping cough; immunization; costs; France