Age‐ and Serotype‐Specific Pediatric Invasive Pneumococcal Disease: Insights from Systematic Surveillance in Santiago, Chile, 1994–2007

Abstract

Background. We monitored pediatric invasive pneumococcal disease (IPD) in Santiago, Chile, from 1994 to 2007. Methods. Three related data sets were generated: (1) IPD cases requiring hospitalization, 1994–2007; (2) cases of bacteremia detected among febrile patients aged 0–35 months seen in emergency departments, 2000–2007; and (3) nasopharyngeal carriage of pneumococcal serotypes, determined from repetitive culturing, among 524 newborns followed up through age 23 months. Results. Of 2369 IPD cases requiring hospitalization, 1878 (79.3%) occurred in those aged 0–59 months, and 1200 (50.7%) occurred in those aged 6–35 months. Among infants aged 0–5 months, meningitis and sepsis comprised 48.4% of all IPD cases (serotype 5 predominated); among those 6–35 months old, 522 (43.5%) of 1200 cases were bacteremic pneumonia (serotype 14 predominated). Serotype 1 peritonitis was common among 5–14-year-old girls. Meningitis and sepsis exhibited high case fatality rates (14%–29%) among all ages. Remarkably, 34 (28.8%) of 118 children with sepsis died, versus 1 fatality (0.4%) among 276 children hospitalized with bacteremia without a focus (P<.001, Fisher's exact test). Serotype 5 was significantly more common among hospitalized patients Conclusions. Clinical syndromes of IPD and predominant serotypes vary with age.