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Sentinel Surveillance based at private medical practitioners (PMPs) Surveillance on Antimicrobial Resistance (2019)

Release date: 25 September 2020


Background

The sentinel surveillance based at private medical practitioners (PMPs), established since 1997, is now a network of PMPs in Hong Kong that provides information for surveillance of communicable diseases at the community level. Surveillance on antimicrobial resistance (AMR) is part of the system through which, appropriate patients are recruited for collection of specimens for microbiological test to monitor the situation of AMR in the community.

Follow the Hong Kong Strategy and Action Plan on Antimicrobial Resistance 2017-2022 as one of its strategic actions, the Government of the Hong Kong SAR is committed to strengthen AMR surveillance in healthcare settings, with efforts to be put on aligning AMR surveillance with international standards, i.e. the Global Antimicrobial Resistance Surveillance System (GLASS) developed by the World Health Organization (WHO).

Starting from 2019, the existing AMR surveillance among sentinel PMPs has been enhanced to collect AMR surveillance data among patients with acute diarrheal disease (ADD) and urinary tract infection (UTI) with reference to AMR surveillance reporting criteria developed by GLASS.


Methodology


Surveillance period

The surveillance period was from 1 January, 2019 to 31 December, 2019.


Scope of priority specimens and pathogens

The scope of priority specimens and pathogens essentially aligned with the Global Antimicrobial Resistance Surveillance System (GLASS) of the WHO with adaptation based on local interest. At the PMP setting, only urine and stool specimens were under surveillance.


Laboratory Testing Method

Culture tests were performed for urine and stool specimens in the Public Health Laboratory Services Branch (PHLSB) of the Centre for Health Protection (CHP) according to its pre-defined laboratory protocol. Selected antimicrobial susceptibility tests were performed when the priority pathogens were isolated, i.e., Escherichia coli and Klebsiella pneumoniae for urine; Salmonella spp. and Shigella spp. for stool, respectively.


Data analysis and reporting

Surveillance data was analysed with descriptive statistics compiled according to GLASS.

In terms of antimicrobial susceptibility testing, breakpoints for antimicrobial susceptibility from relevant guidelines of the Clinical & Laboratory Standards Institute (CLSI) and the European Committee on Antimicrobial Susceptibility Testing (EUCAST) was adopted by PHLSB wherever appropriate.

Antimicrobial susceptibility test (AST) results are classified as below:

  • Susceptible (S): isolates that were tested and interpreted as “susceptible” to a given antimicrobial in accordance with the clinical breakpoint criteria used.
  • Intermediate (I): isolates that were tested and interpreted as “intermediate” to a given antimicrobial in accordance with the clinical breakpoint criteria used.
  • Resistant (R): isolates that were tested and interpreted as “resistant” to a given antimicrobial in accordance with the clinical breakpoint criteria used.

Results


Sentinel clinics participated

  • Total number of sentinel clinics: 64
  • Number of clinics which had submitted specimens: 10
  • Submission rate (no. of clinics submitted specimens per total no. of sentinel clinics): 15.6%

Number of patients with specimens collected

Stool and urine specimens were collected from 67 and 212 patients after deduplication1 respectively.


Surveillance results from urinary specimens


Patient Demographic characteristics

  • During the surveillance period, a total of 212 urine specimens were collected from patients with symptoms of urinary tract infection and fulfilling the selection criteria.
  • Among all the patients, there were more female than male, of which 160 (75.5%) patients were female and 52 (24.5%) were male.
  • Among the female patients being sampled, 31 (19.4%) belonged to the 55 - 64 age group, of which they contributed the largest proportion of sampled female patients. Similarly, a total of 8 (15.4%) male patients being sampled belonged to the 45 - 54 age group, of which they contributed the largest proportion of sampled male patients.

Culture results

  • Among the 212 specimens, 87 (41.0%) of them were positive for bacterial culture.2 A total of 90 bacterial isolates were obtained.3
  • 57 (65.5%) isolates were identified as Escherichia coli, which was the commonest urinary pathogen detected among all positive specimens
  • 7 (8.0%) isolates were identified as Klebsiella pneumoniae
  • For other species, the three commonest isolates were Proteus mirabilis (6 isolates (6.9%)), Citrobacter species (5 isolates (5.7%)), and Enterococcus species (5 isolates (5.7%)).

Antimicrobial susceptibility test results


Resistance to the commonly used first-line oral antimicrobials

  • None of the 57 Escherichia coli isolates was resistant to Nitrofurantoin. For Klebsiella pneumoniae, 1 (14.3%) out of 7 isolates was resistant to Nitrofurantoin.
  • Regarding Amoxicillin/ Clavulanic acid, 3 (5.3%) of Escherichia coli  and none of the Klebsiella pneumoniae isolates were resistant to this antimicrobial.

Resistance to second-line oral antimicrobials

  • There were 23 (40.4%) Escherichia coli and 2 (28.6%) Klebsiella pneumoniae isolates tested resistant to Co-trimoxazole.
  • There were 14 (24.6%) Escherichia coli and 1 (14.3%) Klebsiella pneumoniae isolates tested resistant to fluoroquinolones (Levofloxacin).

Resistance to parenteral antimicrobials

  • For parenteral antimicrobials, 9 (15.8%) Escherichia coli and 2 (28.6%) Klebsiella pneumoniae isolates were resistant to Cefotaxime, while 2 (3.5%) Escherichia coli and 1 (14.3%) Klebsiella pneumoniae isolates were resistant to Ceftazidime.
  • All Escherichia coli and Klebsiella pneumoniae isolates from urine specimens were susceptible to the two carbapenems tested, namely, Imipenem and Meropenem.

Surveillance results from stool specimens


Patient Demographic characteristics

  • During the surveillance period, a total of 67 stool specimens were collected from patients with symptoms of acute diarrhoeal diseases.
  • Among all the patients, there were more female than male, of which 34 (50.7%) patients were female and 33 (49.3%) were male.
  • Among the female patients being sampled, 6 (17.6%) belong to the 55 - 64 age group, of which they contributed the largest proportion of sampled female patients. Similarly, a total of 8 (24.2%) male patients being sampled, belonged to the 45 - 54 age group, of which they contributed the largest proportion of sampled male patients.

Culture results

  • Among the 67 specimens, 16 (23.9%) were positive for bacterial culture.4 A total of 17 bacterial isolates were obtained.5
  • Salmonella spp.: 8 (50.0%) isolates, which was the commonest pathogen detected among all positive specimens.
  • No Shigella spp. were identified from stool specimens during the surveillance period.
  • For other species, four types of microorganisms were isolated: Campylobacter jejuni (4 isolates (25.0%)), Aeromonas species (2 isolates (12.5%)), Vibrio alginolyticus species (2 isolates (12.5%)), and Plesiomonas shigelloides (1 isolate (6.3%)).

Antimicrobial susceptibility test results


Resistance to selected antimicrobials

Among the 8 Salmonella spp. isolates identified from stool specimens,

  • 3 (37.5%) isolates were resistant to Ampicillin, none of them were resistant to Co-trimoxazole, and no isolates were resistant to Fluoroquinolones (Ciprofloxacin).
  • None of the isolates were resistant to Ceftriaxone, none of the isolates were resistant to Ceftazidime also.
  • No isolates were resistant to carbapenems (i.e. Imipenem and Meropenem).

Conclusion

This surveillance exercise helps to contribute to the understanding of antibiotic resistance of two common infections, namely urinary tract infections and acute diarrhoeal diseases, in the primary care setting. With continuous information collected from the primary care setting, together with surveillance data from other sources, this sentinel surveillance based at private medical practitioners supports the provision of complementary information for a better understanding of AMR situation in Hong Kong.

Antimicrobial resistance remains a serious threat in the world and Hong Kong is of no exception. Concerted efforts of the healthcare sector, general public and all stakeholders in the community and all over the world are required to combat AMR.

Primary care is the first level of care in the whole healthcare system. Family doctors are the main providers who play a pivotal role in tackling AMR problem by reducing unnecessary antibiotic use.  In this regard, a programme promulgated by the Centre for Health Protection, namely the Antibiotic Stewardship Programme in Primary Care6, aims to optimize antibiotic use in primary care setting by providing evidence-based antibiotic prescription guidance for common infections in community settings for doctors and healthcare professionals as reference.

Please click here to view the full report.


1 Patient was only counted once for each specimen type during the surveillance period, regardless of the number of specimens submitted.

2 Positive specimen is defined as specimen with significant growth of Escherichia coli, Klebsiella pneumoniae, or other organisms.

3 As the specimen may have more than one isolates detected, the number of isolates can be larger than the number of specimens.

4 Positive specimen is defined as specimen with Salmonella spp., Shigella species, and other organisms.

5 As the specimen may have more than one isolates detected, the number of isolates can be larger than the number of specimens.

6 Please click here for more details on the Antibiotic Stewardship Programme in Primary Care.