Surveillance, Targeted Interventions Critical to Combat Variable Nature of Invasive Pneumococcal Disease

Trends in invasive pneumococcal disease (IPD) have fluctuated greatly over the last 2 decades, with differing serotype prevalence across age groups and major year-to-year variations observed from 1998 to 2021. These new data, published in The Microbe as part of a comparative analysis utilizing generative artificial intelligence, underscores the importance of sustained monitoring and targeted treatment strategies in managing IPD.¹

Invasive pneumococcal disease can be especially dangerous for older adults. | Image Credit: © ProArt Studios - stock.adobe.com

Understanding IPD Trends Can Aid Disease Management

IPD is associated with a major clinical and economic burden for adults across multiple age groups. Adults 50 years and older are recommended to be vaccinated against certain pneumococcal serotypes, as older adults are at the highest risk for severe outcomes due to IPD. One analysis of mortality and hospitalization rates found that in-hospital mortality was most associated with being older than 75 years. IPD presents a clear danger to many, especially given the intense variability in serotypes and incidence of community-acquired pneumonia on a year-to-year basis.^1-3

Combatting IPD requires intense monitoring and surveillance to assess disease prevalence, predict future outbreaks, examine the impact of vaccines, and monitor antibiotic resistance, all with the goal of improving patient outcomes. In this analysis, the current investigators used data from the CDC gathered through Active Bacterial Core surveillance (ABC), which monitors invasive bacterial infections such as IPD through laboratory- and population-based surveillance. Through the combination of AI-driven findings and robust traditional statistical analysis, the investigators aimed to effectively examine the role of vaccination programs and age in forming the epidemiological landscape of IPD.^1,4

Investigators Find Variable Trends

Overall, trends from 1998 to 2021 reemphasized that older age groups report a higher number of cases. There was a significant decline in IPD cases from 2019 to 2020, which may have been influenced by the COVID-19 pandemic; this decline has since stabilized from 2020 to 2021, according to the investigators.¹

For specific serotypes, investigators observed a significant decrease in serotype 14 cases in the less than 2 years of age group, dropping from 246 cases in 2000 to 58 cases in 2001 and contributing to an overall decline during that period. Furthermore, patients in the 65-years-and-older age group indicated a marked reduction in serotype 3 cases, decreasing from 197 cases in 2019 to 64 cases in 2021 in a decline that coincided with the COVID-19 pandemic.¹

To validate their findings, the authors conducted a literature review of pneumonia trends by analyzing peer-reviewed publications from the National Library of Medicine. Results from multiple analyses confirmed their observations. One trial, by Sanchez et al, found that annual mortality rates for IPD in toddlers/preschoolers and infants decreased by 13.5% and 26.0%, respectively, following the introduction of the pneumococcal conjugate vaccine (PCV) in Peru. Tan et al, in their long-term analysis of IPD rates, found significant reductions among children and older adults, with a similar decrease coinciding with COVID-19 vaccine administration that the current investigators observed.^1,5,6

“These findings demonstrate varying serotype prevalence across age groups and significant year-to-year fluctuations, highlighting the importance of continued surveillance and targeted intervention strategies in IPD management,” the study authors concluded. “This analysis provides valuable insights for understanding disease patterns, antibiotic resistance, vaccine effectiveness, and outbreak prediction.¹

REFERENCES

1. Takefuki Y. Comparative analysis of invasive pneumococcal disease (IPD) trends in the US. The Microbe. 2025;7:100298. doi:10.1016/j.microb.2025.100298

2. Gallagher A. Clinical, economic burden of pneumococcal disease consistent across age groups. Pharmacy Times. Published April 22, 2024. Accessed April 21, 2025. https://www.pharmacytimes.com/view/clinical-economic-burden-of-pneumococcal-disease-consistent-across-age-groups

3. Gallagher A. ACIP lowers pneumococcal vaccination recommendation to age 50. Pharmacy Times. Published October 24, 2024. Accessed April 21, 2025. https://www.pharmacytimes.com/view/acip-lowers-pneumococcal-vaccination-recommendation-to-age-50

4. CDC. 1998-2023 serotype data for invasive pneumococcal disease cases by age group from active bacterial core surveillance. Active Bacterial Core Surveillance. Last Updated March 14, 2025. Accessed April 21, 2025. https://data.cdc.gov/Public-Health-Surveillance/1998-2023-Serotype-Data-for-Invasive-Pneumococcal-/qvzb-qs6p/about_data

5. Sanchez CA, Lozada-Urbano M, Best-Bandenay P, et al. Pneumonia mortality trends in children under 5 years of age in the context of pneumococcal conjugate vaccination in Peru, 2003-2017. Vaccines. 2023;11(11):1715. doi:10.3390/vaccines111111715

6. Tan, TQ. Pediatric invasive pneumococcal disease in the United States in the era of pneumococcal conjugate vaccines. 2012;25(3). doi:10.1128/cmr.00018-12