Pneumococcal disease: Epidemiology and new vaccines

Abstract

Streptococcus pneumoniae causes invasive and noninvasive infections. Among infectious diseases, invasive pneumococcal disease (IPD) is a leading cause of morbidity and mortality in children and adults. Community acquired pneumonia in adults is the main presentation of non-IPD and is the most common infectious source of IPD. The incidence, severity and mortality of pneumococcal disease vary widely depending on several factors, some are host related, and others are organism related. After introduction of the vaccine, rates of pneumococcal disease caused by vaccine serotypes have dramatically decreased among vaccinated children, nonvaccinated children, and adults. However, incidents of pneumococcal disease due to new emerging nonvaccine serotypes and antimicrobial resistance have increased. Continuous monitoring and surveillance studies focused on the clinical and molecular epidemiology of pneumococcal disease will be required to understand the impact of the new vaccines and possible alteration in the pattern of disease presentation.