Monitoring of community-acquired pneumonia hospitalisations before the introduction of pneumococcal conjugate vaccine into Polish National Immunisation Programme (2009-2016): A nationwide retrospective database analysis

Abstract

Purpose: Community-acquired pneumonia (CAP) is a common infection with significant morbidity and mortality. In January 2017, Poland introduced pneumococcal conjugate vaccine (PCV) into their national immunisation programme to protect children against invasive pneumococcal disease. This study was designed to investigate pneumonia-related hospitalisation rates and trends from 2009 to 2016 prior to the introduction of nationally funded PCV vaccination.

Methods: Using national public statistic data available from the National Institute of Public Health - National Institute of Hygiene, annual hospitalisation rates for pneumonia were analysed, categorised by aetiology and age (<2, 2-3, 4-5, 6-19, 20-59, 60+ years). Trends over time were assessed, as well as in-hospital mortality.

Results: The overall hospitalisation rate due to pneumonia varied between 325.9 and 372.2/100,000 population. Higher rates of hospitalisation were seen in older adults and children ≤5 years. Trends were observed when analysing hospitalisations by pneumonia aetiology within age groups: between 2009 and 2016, Streptococcus pneumoniae hospitalisations significantly increased for children aged <2, 2-3, and 4-5 years, from 5.3 to 12.4, 5.2 to 8.2, and 1.9 to 4.6/100,000 population respectively. Whereas hospitalisations due to Haemophilus influenzae pneumonia decreased significantly from 7.8 to 1.8 and 4.8 to 1.9/100,000 children aged <2 and 2-3 years respectively. The numbers of in-hospital deaths increased from 5578 in 2009 to 8149 in 2016, with >85% of deaths in the 60+ age group.

Conclusions: This is the first national study of pneumonia hospitalisations in Poland, providing the baseline data from which to investigate the impact of the change in vaccination policy on pneumonia hospitalisations in Poland.

Keywords: Community-acquired pneumonia; Hospitalisation rates; National Immunisation Programme; National public statistic; Pneumococcal vaccination; Poland.