Decrease in the incidence and in hospital mortality of community-acquired pneumonia among children in Spain (2001-2014).

OBJECTIVES: To describe trends in the incidence and outcomes of community-acquired pneumonia (CAP) hospitalizations among Spanish children from 2001 to 2014 and to assess the effect of the pneumococcal vaccination (PCV) coverage in this period.

METHODS: This study was conducted using the Spanish National Hospital Database from 2001 to 2014 including subjects <18years. We selected discharges with a primary diagnosis of CAP. Study variable included age, sex, comorbid conditions, procedures, isolated pathogens and hospital outcome variables. In order to estimate the effect of coverage of pneumococcal vaccination in hospitalizations for CAP, we used the number of commercialized doses of PCV (PCV7 PCV10, and PCV13) for each year. Incidence rates of admissions for CAP were calculated by dividing the number of admissions per year, sex, and age group by the corresponding number of people in that population group according to the census data.

RESULTS: We identified 194,419 admissions for CAP. Incidence rate was highest among children younger than 2years and decreased significantly by 3.67% per year over the study period in this age group. Among children aged 2-4years incidence of CAP seem to decrease after year 2009. S. pneumoniae isolations decreased significantly over time but virus isolations increased. In children aged <2years and 2-4years increase in PVC was associated to a decrease in the incidence of CAP hospitalizations. Overall crude in hospital mortality following CAP fell significantly from 4.1‰ in 2001-2003 to 2.8‰ in 2012-2014.

CONCLUSIONS: CAP incidence rates decreased significantly among children <2years of age from 2001 to 2014. S. pneumoniae isolations decreased significantly over time but virus isolations increased. In hospital mortality paralleling CAP fell significantly in children and adolescents from 2001 to 2014. Improvement in vaccination coverage seems to have a mitigating effect on hospitalizations and outcomes for CAP in children.