1 / 39

Role of the laboratory in surveillance

Role of the laboratory in surveillance. Ph. Dubois, Laboratory for Urgent Response to Biological Threats, Institut Pasteur, Paris. Sources: WHO Laboratory Training for Field Epidemiologists ECDC -EUPHEM Robert Koch Institute National Reference Center for Listeriosis, Paris

pandora
Télécharger la présentation

Role of the laboratory in surveillance

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Role of the laboratory in surveillance Ph. Dubois, Laboratory for Urgent Response to Biological Threats, Institut Pasteur, Paris Sources: WHO Laboratory Training for Field Epidemiologists ECDC -EUPHEM Robert Koch Institute National Reference Center for Listeriosis, Paris Laboratory for Urgent Response to Biological Threats, Paris

  2. Learning objectives At the end of the presentation, participants should: • Understand how the laboratory contributes to epidemiological surveillance • Understand the principles of laboratory-based surveillance • Understand some concerns of public health microbiologists

  3. Laboratories and disease surveillance Before the outbreak • Early warning signals • Outbreak detection During the outbreak • Outbreak response and management In between outbreaks • Trend monitoring • Intervention evaluation • Monitoring progress towards a control objective

  4. Expected results Laboratory: • Confirmation of clinical diagnostic: • Direct identification of the bug • Serology detection • Identification of the strain/isolate/subtype • Identification of new pathogen • Characterization of pathogen sensitivity to antimicrobials • Identification of seroconvertants/carriers in populations • Collection of data/information from patients with various / different geographic origins • Collection of data/information from environmental or animal origin

  5. Expected results Surveillance: • Early warning • Outbreak detection • Post-outbreak surveillance • Environment and reservoir analyses • Surveillance of eradication-elimination of a bug • Surveillance of vaccination campaign • Surveillance of notifiable diseases • Surveillance of national drug treatment efficacy

  6. I - Early warning signals Detection of pathogens that have potential to spread Sentinel events requiring early control measures • Isolation of a single epidemic prone isolate (e.g. non-typhoidal salmonella isolated from a neonate in a hospital neonatal intensive care unit) • Emergence of resistant strains in the hospital or the community (e.g. multi-drug resistant tuberculosis)

  7. Outbreak detection by the lab Identification of a cluster of: • Infections with an unusual pathogen • Specific subtype of a pathogen • Outbreak of antibiotic-resistant strains • Subtypes of a pathogen (e.g. Shigella dysenteriae type I) Reference centres may capture outbreaks disseminated over a large area, or correlate events (food control-cluster of human cases).

  8. Listeria monocytogenesGenoserotyping or PCR Group IIa IIb IIc IVb Multiplex PCR : simultaneous PCR on 5 different DNA fragments Doumith et al. JCM, 2004 Doumith et al., J Food Protect 2005

  9. II - Outbreak confirmation Epidemiologist captures an increased incidence Laboratory: • Confirms the diagnosis • Allows for a more specific case definition • Detects a new pathogen • Provides additional details on the pathogen (e.g., phage type) Examples : detection H5N1, detection H1N1 Effective participation of the laboratory in surveillance requires good communication between the epidemiologists and the laboratories

  10. Laboratory role during outbreaks Laboratory confirmation of early cases • On a subset of cases Identification of new pathogens Typing of the pathogen • Link clusters when the epidemiological data is not sufficient Antimicrobial susceptibility testing to guide treatment Post-outbreak surveillance Environmental investigations Detection of carriers

  11. Laboratory role during outbreaks SARS Courtesy:The University of Hong Kong For new and emerging pathogens: • Identify the pathogen • Develop laboratory tests • Patient treatment/management

  12. III - Monitoring endemic disease trends Confirm diagnosis • Case definitions that include laboratory criteria: Monitor resistance patterns Monitor subtypes of a pathogen • Detection Flu viruses subtypes, such as H5N1, H1N1

  13. Monitoring endemic disease trends Examples: Circulating strains of bacterial meningitis • Impact on treatment protocols • Impact on immunization policies Antibiotic resistance • Methicilin resistant staphylococcus aureus • Vancomycin resistant enterococcus • Tuberculosis • Monitoring of Flu viruses circulation, vaccination policies

  14. Invasive meningococcal infection serogroups by year, France, 1985-2000 Source : InVS and NRC for N. meningitis, Pasteur Institute, Paris

  15. IV - Eradication/elimination monitoring The elimination phase requires more specific tests as positive predictive value decreases Laboratory confirmed diagnosis • Polio surveillance • Measles Typing helps identifying the origin

  16. Cases of polio where wild poliovirus was isolated in children, District X 1980-1996

  17. Monitoring TB control program to ensure complete treatment and cure

  18. V - Monitoring seroconversion/susceptibility Systematic control of immune status for specific diseases Tuberculin reaction Toxoplasmosis

  19. Establishing laboratory support for public health surveillance Identify diseases of public health importance List diseases that require laboratory confirmation Determine tests to be performed Map laboratory facilities and human resources, including reference laboratories Establish laboratory networking Identify a focal person to coordinate laboratory activities Determine information flow

  20. How to identify a new subtype? • Look for genetic material : broad range of genetic probes and methods • Direct isolation : • culture on selective media to obtain clonal populations • Characterize new serotypes • Characterize new chemical or biochemical activities • Characterize new toxins

  21. Pulsed-field gel electrophoresis (PFGE) RFLPs of MRSA isolates with similar ABT ST profile as determined by PFGE; only isolates B & C are identical RFLPs of VRE isolates as determined by PFGE; all appear identical RFLPs of two strains (B & C) from a patient as determined by PFGE; both different implying mixed infection; lane A is marker

  22. How to identify a new resistance to antibiotics • Look for genetic material : broad range of genetic probes and methods for identification of resistance genes. • Direct isolation : • Culture on selective media to obtain clonal populations • Grow isolates on different antibiotics, and determine dose-response curves

  23. How to identify a new pathogen ? Good question !!!!! What if totally unknown, no clue from clinicians, or classical lab techniques ? • Look for genetic material : broad range of genetic probes and methods • Direct examination : light microscopy, electronic microscopy • Direct isolation : • culture on a whole spectrum of bacteriology media and conditions • Culture on a whole spectrum of cell lines permissive for most known viruses

  24. DNA CHIPSPathogenID® Microarray : • 126 virus sequences : • 37 genders • 14 families • 42 virus sequences : • 26 genders • 11 families

  25. Surveillance: Lab functions Confirmation of etiology to resolve syndromic presentation Data intelligence for: • Antimicrobial resistance monitoring • Emergence of unusual isolates • Detection of new pathogens • Sero-surveillance

  26. French surveillance system of listeriosis Regional Agency of Ministry of Economy (DDCCRF) Ministry of Economy (DGCCRF) FI Laboratory of medical microbiology (Private & Public) Regional Agency of Ministry of Agriculture (DDPP) Ministry of Agriculture (DGAl) FI S Patient information M NRC S Food Information Laboratory of food microbiology (Private & Public) Patient Regional Agency of Ministry of Health (ANRS) NRL FQ M FQ Public Health Agency (InVS) M Clinician Legend : FI, Food Incident M, Mandatory Notification S, Strain FQ, Food Questionnaire Ministry of Health (DGS) Cell Listeria

  27. Samples from the field to the lab What samples should you take? And how? • Blood, stools, swabs, water, food items, etc… How should you ship the samples? • High risk material? • Cooling necessary? • “Box in a box in a box principle” Ask the lab and inform that samples are arriving!

  28. The result of any laboratory test is only as good as the sample received in the laboratory

  29. Packaging infectious substances for shipment Triple packaging system Infectious substance (BIOHAZARD) label Container for the first suspected anthrax letter / Berlin Prof. Matthias Niedrig, RKI

  30. Sampling module

  31. Biological Risk Management • Laboratory biosafety: containment principles, technologies, and practices implemented to prevent unintentional exposure to pathogens and toxins, or their unintentional release • Laboratory biosecurity: institutional and personal security measures designed to prevent the loss, theft, misuse, diversion, or intentional release of pathogens and toxins • 1Laboratory biosafety manual, Third edition, World Health Organization, 2004)

  32. Risk Graph Very High High Likelihood Moderate Low Very Low Consequences

  33. High Risk Very High High Likelihood Moderate Low Very Low Consequences

  34. Low risk ? Very High High Likelihood Moderate Low Very Low Consequences

  35. Low Risk Very High High Likelihood Moderate Low Very Low Consequences

  36. Risk assessment

  37. Laboratory Biorisk Management Standard • System or process to control safety and security risks associated with the handling or storage and disposal of biological agents and toxins in laboratories and facilities • CWA 15793:2008

  38. Role of laboratory in surveillance Developed by the Department of Epidemic and Pandemic Alert and Response of the World Health Organization with assistance from: European Program for Intervention Epidemiology Training Canadian Field Epidemiology Program Thailand Ministry of Health Institut Pasteur

  39. THANK YOU FOR YOUR ATTENTION www.enivd.org The ENIVD-CLRN project is funded by the ECDC under the Framework Service Contract Ref. No. ECDC/2008/011.

More Related