Burden of pneumococcal clinical syndromes in Argentina: a retrospective analysis of 2019 national data

Abstract

Argentina incorporated pneumococcal vaccination into its national childhood immunization programme in 2012, achieving coverage above 75% since 2013. In 2017, a sequential regimen was introduced for adults aged ≥ 65 years and at-risk populations. However, data on the pneumococcal disease burden in the country remain limited. This study estimated the burden of clinical syndromes associated with pneumococcal disease across all ages in Argentina in 2019, incorporating attributable fractions (AFs) to quantify the proportion due to Streptococcus pneumoniae . This descriptive, retrospective study used secondary data from the Directorate of Health Statistics and Information (DEIS) of Argentina. Hospitalizations and deaths due to clinical syndromes associated with pneumococcal disease —including pneumonia, meningitis, bacteremia/sepsis, other invasive diseases and otitis media— were identified via ICD-10 codes and stratified by age groups (< 1, 1–4, 0–4, 5–17, 18–49, 50–59, 60–64 and ≥ 65 years). Hospitalization and mortality rates per 100,000 population, and in-hospital case fatality rates (CFR) were calculated. Age-specific AFs were then applied to estimate the potential hospitalization and mortality burden attributable to S. pneumoniae across all syndromes. In 2019, a total of 74,354 hospitalizations and 44,450 deaths due to clinical syndromes associated with pneumococcal disease were recorded in Argentina. The burden was concentrated in infants < 1 year and adults aged ≥ 65 years. Across all syndromes assessed, pneumonia accounted for most hospitalizations ( n  = 62,891; 84.6%) and deaths ( n  = 32,269; 72.6%). CFR increased sharply with age, reaching 17.6% for pneumonia and 67.6% for bacteremia/sepsis in adults aged ≥ 65 years. Mortality rates were highest in those aged  ≥  65 years, at 543.2 per 100,000 for pneumonia and 179.5 per 100,000 for bacteremia/sepsis. After applying age-specific AFs, an estimated 15,282 hospitalizations and 6,402 deaths were attributable to S. pneumoniae across all ages. Despite established vaccination programmes, the burden of clinical syndromes associated with pneumococcal disease in Argentina remained substantial among infants < 1 year and adults aged ≥ 65 years in 2019. These findings support the need to optimize immunization strategies for older populations—potentially through higher-valency pneumococcal conjugate vaccines—and reinforce the importance of maintaining high vaccine coverage and strengthening national surveillance systems.