Epidemiological Study on Invasive Bacterial Diseases

Overview

Streptococcus pneumoniae (pneumococcus), Neisseria meningitidis (meningococcus), and Haemophilus influenzae (hemophilus) are among the main bacteria responsible for invasive bacterial diseases (MBIs) that result in severe clinical pictures also characterized by a high frequency of serious complications. Surveillance of infections caused by these pathogens and their distribution by serotypes/serogroups is essential to guide public health interventions, assess epidemiologic trends, monitor any secondary cases, estimate the proportion of preventable cases, identify any vaccine failures, and evaluate the impact of vaccine strategies.The present study aims to study the epidemiology of invasive bacterial diseases, characterize the circulating strains also in order to plan treatment and prevention strategies.

Pathogen identification by culture methods has been shown to be unsatisfactory, as antibiotic therapy carried out in patients before hospitalization prevents bacterial culture development and subsequent typing in many cases. In addition, technical problems due to sample collection, storage and transport reduce germ viability leading to false negatives in pathogen identification by culture methods. In contrast, molecular diagnosis allows germ identification on biological samples even in the absence of germ viability, thus enabling more accurate diagnosis. Surveillance of infections caused by these pathogens and their distribution by serotypes/serogroups is essential to guide public health interventions, assess epidemiological trends, monitor any secondary cases, estimate the proportion of preventable cases, identify any vaccine failures, and evaluate the impact of vaccine strategies.In 2006, the AOU Meyer Immunology Laboratory received a grant from the National Center for Disease Prevention and Control (NCDC) to develop a molecular diagnostic method for surveillance of invasive infections with Neisseria meningitidis (meningococcal,) Streptococcus pneumoniae (pneumococcus) and Haemophilus influenzae (hemophilus) that would allow identification of the germ on biological samples even in the absence of germ viability, with a view to improving surveillance, prevention and treatment strategies. The project involved performing molecular diagnostic tests on samples from patients referred to hospitals in the Tuscany Region and outside the region. The present study aims to study the epidemiology of invasive bacterial diseases, characterize the circulating strains also in order to plan treatment and prevention strategies.