Invasive bacterial diseases: national surveillance in Italy and vaccination coverage in the Local Health Agency 4 "Chiavarese", Liguria region (Italy).

INTRODUCTION

In 2007 in Italy, the National Institute of Health published a new protocol for the National Surveillance of Invasive Bacterial Diseases, in order to enhance the notification system of these diseases and to improve immunization strategies. Available vaccines to prevent these diseases were introduced for the first time into the 1999-2000 National Immunization Plan (NIP) (vaccination against Haemophilus influenzae type b) and the 2005-2007 NIP (vaccination against Streptococcus pneumoniae and Neisseria meningitidis serogroup C). We evaluated the frequency of invasive diseases, on the basis of the number of notifications, the different immunization strategies in the Italian Regions and the vaccination coverage in Local Health Agency 4 "Chiavarese" (LHA) in the Liguria Region (Italy).

MATERIALS AND METHODS

We evaluated the number of notifications of invasive diseases collected by the national databank coordinated by the ISS (Informative System of Infectious Diseases, SIMI) from 1994 to 2011. We also examined regional regulations concerning immunization policies. Immunization coverage was calculated by means of the "OASIS" software (version 9.0.0) used in our LHA.

RESULTS AND DISCUSSION

Available data indicate that the large-scale vaccination policy begun in 1999 in Italy has led to a great reduction in Haemophilus influenzae-related diseases in the pediatric age. Meningococcal diseases have declined to a lesser degree; this is due to the more recent introduction of vaccination against serogroup C (in 2005), the variability of the immunization strategies adopted in the different Italian Regions and the availability of the vaccination against serogroup C only in the pediatric age. The diseases caused by Streptococcus pneumoniae seem to have increased since 2007 because of the implementation of the Surveillance of Invasive Diseases Program and the subsequent notification of all invasive diseases (not only meningitis). Furthermore, the various Italian Regions have adopted different immunization strategies against this disease, too. We evaluated vaccination coverage in LHA 4 from 2003 to 2008. VC levels against Haemophilus influenzae are excellent; the objective indicated in the 2005-2007 NIP (> or = 95%) has therefore been reached. Vaccination coverage levels against Streptococcus pneumoniae and Neisseria meningitidis serogroup C at the 24th month of age are also good. However, we need to implement specific immunization strategies for adolescents, since the vaccination coverage levels are not completely satisfactory.

CONCLUSIONS

The improvement of the national invasive disease surveillance system has provided better knowledge of the size of the problem and the impact of immunization strategies on the incidence of invasive bacterial diseases. Furthermore, immunization policies in Italy display territorial heterogeneity. Vaccination coverage levels against Haemophilus influenzae, Streptococcus pneumoniae and Neisseria meningitidis at the 24th month in LHA 4 are very high. In adolescents (15 year-olds) the immunization coverage are good but needs to be improved through specific strategies, such as raising the awareness of healthcare workers, involving general practitioners and educating the target population.