Disease Pattern, Risk factors of Antimicrobial Resistance in Patients with Pneumococcal Infection in Hong Kong Population

Background Antimicrobial resistance (AMR) presents significant challenges for the effective treatment of pneumococcal diseases (PD), disease prevalence and vaccine effectiveness caused by S. pneumoniae. Objectives To describe the pattern of AMR among isolates from PD patients reported in the Hong Kong population from 2012-2021, and to explore the risk factors associated with AMR among patients hospitalised with PD compared to those with susceptible isolates. Methods PD-related hospitalizations were identified and grouped into IPD or non-IPD patients. Electronic health records were collected to calculate the healthcare resource utilisation 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 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 COVID-19 pandemic. Overall, 80% of patients had S. pneumoniae which were non-susceptible to ≥1 antibiotic. The percentage of non-susceptibility found to tetracyclines, macrolides, penicillins, fluoroquinolones, were 85%, 79%, 23% and 2% respectively. 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 when compared to older patients (18-64 years). Conclusion 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 PD patients with serotyping results.