Background: The WHO recommends the establishment of sustainable and evidence-based surveillance systems are recommended for the prevention of microbial resistance. For these surveillance systems, all medical microbiology laboratories are required to participate an external quality assessment (EQA) program that covers antimicrobial susceptibility testing (AST). Clinical microbiology EQA panels with 3 isolates have been provided 3 times per year to antimicrobial resistance (AMR) sentinel laboratories in Cambodia since 2012. We evaluated the performance of laboratory testing implemented between 2016 and 2019, based on 4 years EQA results to highlight the main sources of unsatisfactory analytical processes and to suggest areas for improvement. Methods: We analyzed the results of microbiology EQA in 7 AMR surveillance sentinel laboratories from 2016 to 2019, which were coordinated by the National Institute of Public Health (NIPH) under the program of Pacific Paramedical Training Centre (PPTC) from New Zealand. All participating laboratories were required to identify bacteria to the species level, to verify AST results, and to answer a case study question on parasitology. Feedback results and appropriate corrective actions were reviewed to identify the root cause of nonconformity and to suggest areas for improvement. Results: Proficiency test results of participating laboratories from 9 cycles with 27 isolates were analyzed. The overall average of EQA result was 94.0%. The laboratories failed to identify the isolated pathogens in 7.0% of the tests and failed to interpret the inhibition zone of AST (ie, resistant, intermediate or susceptible) in 6.0% of tested strains. The main causes of erroneous of PT results were either preanalytical (ie, handling of the samples, timing of analysis, equipment and reagent management), analytical (ie, quality control, unsuitable methods, confusion of samples, or errors of confirmation), or postanalytical mistakes (eg, interpretation guideline, cross-checking of results, or the information management system). Followed by the root causes, internal quality control and inventory management were the highest-priority suggestions for improvement. Conclusions: All participating laboratories showed good performance on EQA for evidence-based AMR surveillance. The national antimicrobial resistance data quality is sufficiently good and the data should be shared on national and international platforms. However, the regular monitoring of national AMR surveillance system should be conducted for continued quality improvement.

Funding: None

Disclosures: None