Disease pattern and risk factors of antimicrobial resistance in patients with pneumococcal infection in the Hong Kong population

Objectives: Antimicrobial resistance (AMR) presents significant challenges for the effective treatment of pneumococcal disease (PD), disease prevalence, and vaccine effectiveness caused by S. pneumoniae. We aimed to describe the pattern of AMR among isolates from patients with PD reported in the Hong Kong population from 2012-2021, and to explore the risk factors associated with AMR among patients hospitalized with PD compared to those with susceptible isolates.

Methods: PD-related hospitalizations were identified and grouped into invasive PD (IPD) or non-IPD patients. Electronic health records were collected to calculate the healthcare resource utilization relevant to each IPD/non-IPD patient. We compared the characteristics of patients with IPD/non-IPD caused by non-susceptible isolates (cases) and those without (controls) using a multivariable logistic regression model, looking for risk factors for AMR.

Results: The PD incidence trend was stable from 2012 to 2019 with a sudden decrease in 2020, coinciding with the beginning of the COVID-19 pandemic. Overall, 80% of patients had S. pneumoniae non-susceptible to ≥1 antibiotic. The percentage of non-susceptibility found to tetracyclines, macrolides, penicillin, and fluoroquinolones, were 85%, 79%, 23% and 2%, respectively. Overall, 46% of the patients with serotyping results were serotype 3. Significantly increased odds of AMR infection were found among the non-IPD patients aged 2-17 years when compared to older patients (18-64 years).

Conclusions: Measures to reduce non-susceptible S. pneumoniae infections should focus on children and adolescents of school age. Despite the introduction of PCV13 in 2011, serotype 3 and AMR continued to threaten people in the community. Serotype 3-infected patients accounted for nearly half of the patients with PD with serotyping results.

Keywords: Pneumococcal disease, Pneumococcal conjugate vaccine, Antimicrobial resistance, Electronic health record

Recommended citation: Lau, J. C. H., Cheung, K. W. K., Yu, Q., Wu, P., Wong, S. C., Cheng, V. C. C., Tam, E. Y. T., Kwan, M. Y. W., Hung, I. F. N., Wong, I. C. K., Moore, C. E., Khan, T. K., Sukarom, I., Lao, K. S., & Chui, C. S. L. (2025). Disease pattern and risk factors of antimicrobial resistance in patients with pneumococcal infection in the Hong Kong population. International Journal of Infectious Diseases, 161, 108174. https://doi.org/10.1016/j.ijid.2025.108174
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