Bacteremic pneumococcal community-acquired pneumonia in children less than 5 years of age in Italy

Background: This study was designed to determine the proportion of bacteremic pneumococcal cases in a group of pediatric subjects with community-acquired pneumonia (CAP), the importance of the different serotypes and the impact of the currently available pneumococcal conjugate vaccines (PCVs). Methods: The study involved children who were ≤5 years with radiographically confirmed CAP admitted to hospital in Italy between September 2008 and March 2011. A diagnosis of laboratory-confirmed bacteremic pneumococcal CAP was made in the presence of a culture and/or real-time polymerase chain reaction (PCR) positive for Streptococcus pneumoniae. Results: A total of 510 children were included in the study. Pneumococcal CAP was diagnosed in 73 cases (14.3%): S. pneumoniae was identified by means of positive real-time PCR in 67 cases (91.8%), a positive blood culture in 1 (1.4%) and both in 5 (6.8%). Complicated pneumonia was observed significantly more often in the pneumococcal-positive cases (P = 0.02) and empyema was the main complication (P = 0.007). Serotype 19A was most frequently encountered (17 cases; 25.8%), followed by serotypes 14 (10 cases, 15.1%), 4 (5 cases, 7.6%) and 3 (4 cases, 6.1%). The theoretical coverage offered by the available PCVs was calculated to be 31% for PCV7, 37% for PCV10 and 71% for PCV13. Conclusions: In Italy, bacteremic pneumococcal CAP accounts for a significant number of CAP cases in children who were ≤5 years, with serotypes 19A and 14 being the most frequent. This suggests that PCV13 is the best means of preventing pneumococcal CAP.