In addition to a direct effect on the individual, the consumption of antiinfective drugs may have an indirect ecological benefit only visible at the population level. Moreover indirect ecological adverse effects may also exist (bacterial resistance, vaccine escape). To fight against invasive pneumococcal diseases in the community (IPD) and S.pneumoniae resistance to antibiotics, France has initiated two public health interventions, the campaign to promote better-targeted antibiotic use, which has led to a significant decrease in their prescriptions, and the promotion of 7-valent pneumococcal conjugate vaccine (PCV-7), followed by PCV-13. Despite the decline in the incidence of IPD due to vaccine serotypes, the benefit of vaccination has been reduced or neutralized by the serotype replacement phenomenon in all age groups. In accordance with works that suggest that bacterial complications are important in the consequences of infections, and beyond that reduced exposure to antibiotics may be associated with a re-increase in some IPD mainly of sensitive strains, a significant increase of IPD in 16-64 yrs was estimated in 2008, compared with those in 1998. It is therefore important to study the temporal dynamics of IPD in relation to public health interventions. This project is funded by the Fondation pour la Recherche Médicale (FRM) and the Université de Versailles Saint Quentin (PhD fellowship).
Keywords: Invasive pneumococcal diseases, Time series, Antibiotics, PCV vaccination