Disease Pattern, Serotype Distribution and Healthcare Resources Utilisation of Antimicrobial Resistance in Patients with Pneumococcal Infection in Hong Kong – A Population-based Study

Background: Antimicrobial resistance (AMR) presents significant challenges for the effective treatment of pneumococcal diseases (PD) caused by Streptococcus pneumoniae (S. pneumoniae) and varied with the serotype.

Objectives: To describe the epidemiology and pattern of AMR among PD episodes from 2012-2021. Further, to explore the relevant healthcare resources utilisation (HCRU) among PD-related hospitalisation compared to those with isolate susceptible to antibiotics.

Methods: We retrieved data from the Hong Kong Clinical Data Analysis and Reporting System. PD-related hospitalisations were identified by diagnostic codes in International Classification of Diseases, Ninth Revision, Clinical Modification codes. Antimicrobial susceptibility tests (AST) and serotyping results were retrieved to describe the AMR status and epidemiology. Patient demographics and administrative data were collected to summarise the HCRU relevant to the PD episode.

Results: Out of 2,286 PD episodes identified from 2,255 patients, 80% (n=1,823) of the episodes were non-invasive PD-related. The PD incidence trend was stable from 2012 to 2019 until a sudden decrease in 2020, coinciding with the public health measures implementation during COVID-19 pandemic. 80% of the PD episodes had S. pneumoniae isolates with non-susceptibility against at least one antibiotic. The highest rates of non-susceptibility were found in tetracyclines (86%), lincosamides (80%), and macrolides (79%). Among the 355 PD episodes with serotyping results, 46% were serotype 3. For HCRU, the length of stay, average number of all prescriptions and proportion of IPD cases, are higher among episodes with susceptible isolates when compared to those with non-susceptibility to one or more antibiotic classes.

Conclusions: S. pneumoniae isolates had the highest non-susceptibility to tetracyclines, lincosamides, and macrolides in Hong Kong whilst existing literature reported non-susceptibility rate to penicillins or third-generation cephalosporins. Despite the introduction of PCV13 in 2012, serotype 3 and AMR continue to threaten the community, particularly among those at schooling age. Serotype 3-related episodes accounted for nearly half of PD episodes with serotyping results. The HCRU relevant to PD episodes seems not to be related to the AMR status of the S. pneumoniae isolates, which suggest further in-depth investigation for the factors affecting the HCRU.