Invasive Pneumococcal Disease and Pneumococcal Pneumonia

Abstract

Invasive pneumococcal disease is defined as an infection confirmed by the isolation of Streptococcus pneumoniae from a normally sterile site. Its incidence in any population is affected by geographic location, time of year, serotype prevalence, age, and vaccination status, and in general invasive pneumococcal disease is more frequent in patients with certain underlying medical conditions or demographic risk factors. These include: age below 2 or 65 years and above; certain racial/ethnic groups; chronic cardiovascular, pulmonary, liver, or renal disease; diabetes mellitus; alcohol abuse; smoking; or immunosuppressive conditions. All over the world, routine vaccination in young children with pneumococcal conjugate vaccines causes significant decline in the incidence of invasive pneumococcal disease in children below 5 years (the age group targeted for vaccination), older children, and adults. As the mortality of pneumococcal pneumonia has not changed for many years despite the different available antimicrobial agents, prevention of pneumococcal infection by vaccination seems to be a rational approach to further decrease the public burden of the disease.