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Resistance data can be used to support decisions on antibiotic therapy, predict the outcome of antibiotic treatment 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.

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 can be used for measuring a variety of components related to antibiotic resistance. Data is collected at a specific point or period of time; it can be during a single day or repeatedly during a specific period of time. Several parameters are usually measured at the same time and can hence provide comprehensive results in a short time. 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 for the identification of local resistance trends, gives visibility to see changes in trends and the emergence of new resistant strains. The WHO Global Antimicrobial Resistance Surveillance System (GLASS) was launched by WHO in 2015 in an effort to standardize surveillance. In 2018, the first report from GLASS was released to the public domain. It shows that many countries have limited surveillance of antibiotic resistant bacteria. Setting up national surveillance is discussed further in POLICY: Elements of a national action plan – Surveillance of antibiotic resistance.

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

Susceptibility testing is currently the standard method used to determine if bacteria are susceptible or resistant to antibiotics. In these standardized procedures, bacterial isolates from patient samples (for example blood, urine, feces or samples taken from the respiratory tract, wounds or joints) are cultured and then tested to determine their susceptibility to different antibiotics.

The most frequently used susceptibility tests are disc diffusion tests and minimum inhibitory concentration (MIC) tests. The MIC is the lowest concentration of an antibiotic needed to inhibit the growth of the bacterium in question. 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 as it is a commercial resource, there is a fee for use. It is important to note that breakpoints and recommendations may differ between different countries. All results should be reported, whether bacteria are susceptible or resistant.

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. Specimen representativeness and handling are two crucial elements that affect the results. Also, for monitoring bacterial resistance rates, an adequate number of collected samples is important.

External quality assessment tools

Hospitals and laboratories undertaking surveillance activities should also participate in an external quality assessment 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
  • Databases & interactive maps
  • Data and reports

Selected Resources

Tools and guidelines

Resource Description
GLASS – Global antimicrobial Resistance Surveillance System – Manual for early implementation The GLASS manual details the approach for early implementation of the surveillance system and is 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.
AMR Surveillance in low- and middle-income settings: A roadmap for participation in the Global Antimicrobial Surveillance System (GLASS) Information and resources for implementation of surveillance in low resource settings. The guideline is aligned with the Global Antimicrobial Resistance Surveillance System (GLASS) procedures but offers higher flexibility across different systems.
Antimicrobial susceptibility testing by EUCAST Step by step information 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.
Manual for the laboratory identification and antimicrobial susceptibility testing of bacterial pathogens of public health importance in the developing world This manual describes how to identify bacterial pathogens and how to perform susceptibility tests, with a focus on LMICs (WHO).
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.
Global Point Prevalence Survey on Antimicrobial Consumption and Resistance  This open to join project 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, data collection templates and presentations in different languages for personal use click here. A scientific article with results from the project has been published in the Lancet Global Health.
Central Asian and Eastern European Surveillance on Antimicrobial Resistance (CAESAR) CAESAR project webpage. The CAESAR project is coordinated by WHO EURO and 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.
European Antimicrobial Resistance Surveillance Network (EARS-Net) EARS-Net is a network of national surveillance systems across Europe that provide European reference data on antibiotic resistance for public health purposes. The network is coordinated and funded by the European Centre for Disease Prevention and Control. On this page it is possible to access surveillance reports and the protocol for reporting into EARS-Net.
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.
Policy and procedures of the WHO/NICD Microbiology External Quality Assessment Programme in Africa Years 1 to 4: 2002-2006 This document describes the WHO/NICD microbiology EQA programme, some policies and procedures and provides samples of technical documents.
Information on 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.
Towards Enhanced Surveillance of Antimicrobial Resistance in the WHO African Region This guide 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.
WHONET Software WHONET is a 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.

Databases & interactive maps

Resource Description
HealthMap ResistanceOpen Interactive global map with data of antibiotic resistance. It is open for collaboration where independent sources may contribute with data.
Resistance Map ResistanceMap provides interactive charts and maps summarizing national and sub-national data on antimicrobial use and resistance around the world.
NARMS Now: Human Data In this interactive tool from the CDC you can find out how antibiotic resistance has changed in the US over the past 20 years for four bacteria transmitted commonly through food: Campylobacter, E. coli O157, Salmonella, and Shigella. Based on data from the National Antimicrobial Resistance Monitoring System (NARMS), and bacteria isolated from humans.

Data and reports

Resource Description
Global antimicrobial resistance surveillance system (GLASS) report, 2018 This WHO report examines the current status of participation and data submitted to GLASS.
Antimicrobial resistance: global report on surveillance, 2014 This WHO report from 2014 describes the current status of surveillance and information on antimicrobial resistance (AMR) at country level worldwide.
Central Asian and Eastern European Surveillance of Antimicrobial Resistance. Annual report 2017 This report presents country resistance data gathered through the WHO Central Asian and Eastern European Surveillance of Antimicrobial Resistance (CAESAR) network. The report aims to provide guidance and inspiration to countries that are building or strengthening their national systems for antimicrobial resistance surveillance and to stimulate data sharing.
Red Latinoamericana de Vigilancia de la Resistencia a los Antimicrobianos This website provides monitoring reports on antimicrobials resistance from the Latin American Network for Monitoring Antimicrobial Resistance. Information is provided in Spanish.
ECDC/EFSA/EMA joint reports on the integrated analysis of the consumption of antimicrobial agents and occurrence of antimicrobial resistance in bacteria from humans and food-producing animals (JIACRA reports) Using existing data from Europe, ECDC/EFSA/EMA analyze the relationship between antimicrobial consumption and resistance to the same antimicrobials in bacteria from humans and animals.
Surveillance of antimicrobial resistance in Europe This website provides annual EARS-Net reports on surveillance in Europe developed by the European Centre for Disease Prevention and Control (ECDC).
Annual epidemiological report – Antimicrobial resistance and healthcare-associated infections 2014 This report includes epidemiological data collected from the Member States to the European Surveillance System on antimicrobial resistance, consumption and health care-associated infections in 2012, published by the European Centre for Disease Prevention and Control (ECDC).
Country-specific reports: Canada; Denmark; the Netherlands; Norway (bottom of page); Sweden Many countries collect country-specific surveillance data on antibiotic resistance in pathogenic, zoonotic, and indicator bacteria from humans and in some cases animals and food, and publish the results regularly. These are examples of country reports, click on the country to access the reports.
Strengthening the Role of Laboratories in Tracking Antimicrobial Drug Resistance in East Africa A 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.

Laboratory-based nationwide surveillance of antimicrobial resistance in Ghana

The study aimed to generate baseline data on antimicrobial resistance and to assess the readiness of laboratory-based surveillance in Ghana.

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