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Resistance data can be used to support decisions on antibiotic therapy and may facilitate development or revision of treatment guidelines. Data can further be used to inform key stakeholders of the scale of the problem. Here you find guidance, methods and tools to measure antibiotic resistance patterns in bacteria isolated from humans, and can access selected databases and reports on the topic.

Data can be generated on a small or large scale. Conducting point prevalence studies or surveys is a good way to get started and can be useful to quickly assess the current situation. It is usually also possible to find some evidence of the resistance situation from for example scientific studies or initiatives within countries. Over time efforts can be scaled up and eventually act as inputs to national surveillance.

GARP Situation Analyses

The Global Antibiotic Resistance Partnership (GARP) has in collaboration with specific countries conducted national situation analyses focusing on antibiotic use and resistance. Click on the respective country to access the reports:

Point prevalence studies

Point prevalence studies (PPS) can be used for measuring a variety of components related to antibiotic resistance. Several parameters are usually measured during a limited period of time, for example one day. It can hence provide comprehensive results with relatively little effort. The studies can be repeated and thereby also provide useful data on trends and outcomes of interventions. Data from point prevalence studies can be used and analyzed independently or can be an input to larger surveillance efforts.

National surveillance systems

Broad-scale surveillance of antibiotic resistant bacteria of public health importance allows tracking of resistance trends and identification of new resistant strains. The WHO Global Antimicrobial Resistance Surveillance System (GLASS) was launched by WHO in 2015 in an effort to standardize surveillance across the world. Setting up national surveillance is discussed further in POLICY: Elements of a national action plan – Surveillance of antibiotic resistance. See also resources below.

Selecting pathogens and antibiotics

Selection of key pathogens and which antibiotics that should be tested on each isolate should be made prior to collecting antibiotic resistance data. It is also important to monitor which types of infections are prevalent within different settings to be able to choose relevant pathogens to monitor for resistance, see MEASURE – Infections for more information.

Susceptibility testing of bacteria

The most frequently used tests to determine if bacteria are susceptible or resistant to antibiotics are disc diffusion tests and minimum inhibitory concentration (MIC) tests. The MIC is the lowest concentration of an antibiotic that inhibits the growth of a bacterium. In order to determine if a bacterial strain is resistant to a specific antibiotic, clinical MIC break point values are used as guidelines. For example, the European Committee on Antimicrobial Susceptibility testing (EUCAST) provides break point values used in the European countries and are free of charge. The Clinical and Laboratory and Standards Institute (CLSI) also provides break point values, however, there is a fee for use. All results should be reported, whether bacteria are susceptible or resistant.

Please note that it is very important that all products used in susceptibility testing are of good quality. EUCAST issues warnings about known quality issues on their website.  

The microbiology laboratory

The clinical microbiology laboratory is an essential component of work to measure and monitor resistance in bacteria and for correct treatment of infectious diseases. For accurate results, the collection of patient samples should be standardized and follow good laboratory practice. Samples should be handled according to the methods described in manuals for basic laboratory procedures. It is important to take into consideration if the samples need to be transported to other laboratories for analysis, and make suitable preparations. Also, for monitoring bacterial resistance rates, an adequate number of samples is needed.

External quality assessment tools

Hospitals and laboratories undertaking surveillance activities should also participate in an external quality assessment (EQA) program. EQA is used for comparing the results from individual laboratories in the network with reference results. The WHO/NICD Microbiology EQAs program in Africa developed a manual that contains summaries of surveys and technical documents for setting up EQA programs.

Resources below have been divided into the following tables:

  • Tools and guidelines
  • Surveillance systems
  • Databases & interactive maps
  • Data and reports

One Health resources are found on the Antibiotic resistance page. For more on measuring the burden of resistance see MEASURE – Burden.

Selected Resources

Tools and guidelines

Resource Description
Towards Enhanced Surveillance of Antimicrobial Resistance in the WHO African Region”] Guideline that provides background information and defines the key steps for countries to conduct antimicrobial resistance surveillance for meningitis, bacteraemia and common enteric diseases in a national bacteriology reference laboratory. Also available in French and Portuguese.
Proposed Minimum Reporting Guidelines for Research on Antimicrobial Resistance, Appendix in: A review of 40 years of enteric antimicrobial resistance research in Eastern Africa: what can be done better?”] Review discussing research on antimicrobial resistance in enteric bacteria conducted in Eastern Africa up until March 2014. Suggests minimum reporting guidelines for designing antibiotic resistance studies to allow accurate conclusions and comparisons between studies. Also discusses how inadequate study design and a bias towards hospital sampling rather than community-wide sampling often make conclusions about the magnitude and trends of resistance difficult. While article discusses African studies, the proposed guidelines should be applicable in any setting.
Microbiology Investigation Criteria for Reporting Objectively (MICRO): a framework for the reporting and interpretation of clinical microbiology data”] Journal article proposing a framework (MICRO) for reporting and interpreting clinical micobiological data. The purpose is to achieve comparability between studies to inform policy and practice. Table 4 includes a checklist of 20 items that should be adressed. Developed by an international working group and was based on datasets from LMICs in South and South East Asia.
Key elements of a laboratory-based national surveillance program for antimicrobial resistance, including guidance on how to choose organisms and antimicrobials to be included as well as technical information on susceptibility testing and quality control, developed by the WHO Regional Office for South-East Asia.
Community-Based Surveillance of Antimicrobial Use and Resistance in Resource-constrained settings: Report on five pilot projects (PDF, 1MB)”] Manual describing implementation of community-based surveillance of antibiotic resistance and use through five pilot projects in resource‐constrained settings.
Global Point Prevalence Survey on Antimicrobial Consumption and Resistance ”] Open to join PPS project that monitors antimicrobial prescribing and resistance in hospital patients on all continents through a “one day survey” and helps design hospital interventions to promote prudent use. Hospitals are welcome to join survey and network (already more than 300 institutions from over 50 countries have participated). For documents such as protocols, and data collection templates in different languages (incl. Spanish, French and Arabic) for personal use click here. Numerous scientific publications with results from the project have been published.
WHONET Software”] Database software for the management and analysis of antibiotic resistance data. The software is free to download and use and is developed and maintained by WHO.
Manual for the laboratory identification and antimicrobial susceptibility testing of bacterial pathogens of public health importance in the developing world”] Manual that describes how to identify bacterial pathogens and how to perform susceptibility tests, with a focus on LMICs (WHO).
Antimicrobial susceptibility testing by EUCAST”] Step by step guidance on how to do susceptibility tests, including clinical breakpoint tables, developed by the European Committee on Antimicrobial Susceptibility Testing (EUCAST).
Instruction videos for antimicrobial susceptibility testing (AST)”] Video instructions on how to do antimicrobial susceptibility testing using EUCAST recommended methods and interpretation. By EUCAST in collaboration with the WHO. Subtitles available in several languages, including French, Spanish, Chinese, Russian and Arabic.
Methods of Antimicrobial Susceptibility Testing Educational Resource (MASTER) eLearning Curriculum”] Online course on antimicrobial susceptibility testing for bacteria isolated from clinical specimens. For laboratory professionals with knowledge of basic medical microbiology and others responsible for microbiology laboratories. Based on CLSI guidelines, requires registration.
GLASS method for estimating attributable mortality of antimicrobial resistant bloodstream infections”] Protocol. Master template protocol from WHO GLASS for estimating in-hospital mortality attributable to resistant blood stream infections. Focuses on ESBL E. coli and MRSA infections of both community and hospital-origin. Can be expanded to other bacteria as well. Can also support tracking of progress towards the sustainable development goals and specifically the AMR indicator.
Analysis and Presentation of Cumulative Antibiograms: A New Consensus Guideline from the Clinical and Laboratory Standards Institute”] Journal article discussing things to keep in mind when creating and reading antibiograms (based on CLSI-standards).
Protocol: a ‘One health’ two year follow-up, mixed methods study on antibiotic resistance, focusing children under 5 and their environment in rural India”] Protocol: A published protocol for studying antibiotic resistance in children and their environment.

Surveillance systems

Resource Description
AMR Surveillance in low- and middle-income settings: A roadmap for participation in the Global Antimicrobial Surveillance System (GLASS)”] Guide. Information and resources for implementation of surveillance in low resource settings. The guide is aligned with the Global Antimicrobial Resistance Surveillance System (GLASS) procedures but offers higher flexibility across different systems.
GLASS – Global antimicrobial Resistance Surveillance System – Manual for early implementation”] Manual that details the approach for early implementation GLASS. Intended for national public health professionals and authorities in charge of surveillance of antibacterial resistance in humans. Also available in Chinese, French, Russian, and Spanish. See also GLASS resource centre for guidelines and tools for enrolment, data management and capacity building, the implementation reports
Central Asian and Eastern European Surveillance on Antimicrobial Resistance (CAESAR)”] Website of the CAESAR project coordinated by WHO EURO, which aims to set up national antimicrobial resistance surveillance systems in European countries that are not part of EARS-Net. See also accompanying manual with protocols and instructions for routine data collection and antimicrobial case definitions, and the annual report.
Red Latinoamericana de Vigilancia de la Resistencia a los Antimicrobianos”] Website that provides information about the Latin American Network for Monitoring Antimicrobial Resistance (ReLAVRA) coordinated by PAHO. Information is provided in Spanish. Reports from the network are also available.
European Antimicrobial Resistance Surveillance Network (EARS-Net)”] Website of EARS-Net, a network of national surveillance systems across Europe that provide European reference data on antibiotic resistance. The network is coordinated and funded by the European Centre for Disease Prevention and Control. On this site it is possible to access surveillance reports, epidemiological reports and the protocol for reporting into EARS-Net.

Databases & interactive maps

Resource Description
ResistanceMap”] Interactive charts and maps summarizing national and sub-national data on antimicrobial use and resistance around the world.

Data and reports

Resource Description
Aetiology of invasive bacterial infection and antimicrobial resistance in neonates in sub-Saharan Africa: a systematic review and meta-analysis in line with the STROBE-NI reporting guidelines”] Journal article. Systematic review assessing causes and antibiotic resistance of invasive bacterial infections in babies on the African continent. Found high level of resistance to antibiotics recommended for treatment by the WHO.
PARN website ”] Information portal. Website of the Pakistan Antimicrobial Resistance Network (PARN). Provides online courses upon registration, tools and information for laboratory personnel and antibiotic resistance data of bacterial isolates collected at Pakistani hospitals.
Strengthening the Role of Laboratories in Tracking Antimicrobial Drug Resistance in East Africa”] Report reviewing costs and benefits of AMR surveillance, and whether the East Africa Public Health Laboratory Networking Project laboratories are ready to participate in national AMR surveillance.

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