G Regula

Antimicrobial resistance in the veterinary field - risk-basedapproaches applied in Switzerland : Antimicrobial resistance in the veterinary field - risk-based approaches applied in Switzerland Gertraud Regula, Ursula Ledergerber, Katharina D.C. Stärk Swiss Federal Veterinary Office, Bern, Switzerland


Background : Background Growing concern about the negative impact of resistant bacteria on human health Antimicrobials used in veterinary medicine can contribute to resistance in humans Zoonotic pathogens Transfer of resistance genes Direct transmission (contact to animals) Food-borne infection


Role of lifestock production in antimicrobial resistance : Role of lifestock production in antimicrobial resistance Human antimicrobial use Human use Veterinary use Veterinary use Expert opinion Risk perception  4 % Bywater and Casewell, J Antimicrob Chemother, 2000 80 % of Swiss consumers: Residues in food important Swiss National Science Foundation, 2003


Initiatives in Switzerland : Initiatives in Switzerland Integrated approach Human medicine Veterinary medicine Risk-based surveillance Food Environment Emphasis on communication


What is „risk-based“ ? : What is „risk-based“ ? Risk-based = An activity conducted with reference to (one or several of the following) The probability of the occurrence of an adverse event The consequences of an adverse event The management of a risk The perception of a risk An activity conducted with reference to risk analysis


Why risk-based? : Why risk-based? Objectives Promote efficient risk management Prioritisation Adequate resource allocation Optimise cost-benefit ratio Provide transparency


Risk-based surveillance : Risk-based surveillance A surveillance programme in the design of which exposure and risk assessment methods have been applied together with traditional design approaches in order to assure appropriate and cost-effective data collection.


Risk analysis (OIE code) : Risk analysis (OIE code) Hazard identification Risk assessment Risk management Risk communication Release assessment Exposure assessment Consequence assessment Risk estimation


Where to start ? : Where to start ? Hazard identification


Project International Epi Lab, Denmark (U. Ledergerber, H. Wegener et al.) : Project International Epi Lab, Denmark (U. Ledergerber, H. Wegener et al.) RISK PROFILING Identification of hazards (specific bug/drug-resistance)


Risk Profiling: Resistances : AB important for treatment Negative health impact Zoonotic potential Risk Profiling: Resistances Antimicrobials / Resistance / Bacteria


Slide12 : Result: 15 hazards of interest Enterococci (VRE): Vancomycin Fluoroquinolones; Ampicillin; Cephalosporins Fluoroquinolones; Macrolides Fluoroquinolones Penicillins Fluoroquinolones; Ampicillin; Cephalosporins; Carbapenems Aminoglycosides; TMP-SMX E.coli: L.monocytogenes: Y.enterocolitica: Campylobacter: Salmonella: Staph. Aureus (MRSA): Methicillin


Slide13 : Significance of a hazard: Health-impact / Transmission-capacity / Occurrence Risk Ranking


Slide14 : Health impact: bacteria/ resistance combinations


Release assessment : Release assessment How much is out there ?


Release assessment : Release assessment Data are needed on: Use of antimicrobials Prevalence of resistant bacteria Random sample: Enormous number of samples Rare pathogens difficult to monitor Risk-based surveillance


Risk-based monitoring: Project Swiss Federal Veterinary Office : Risk-based monitoring: Project Swiss Federal Veterinary Office Use information from risk assessment for the design of a sampling protocol Targeted sampling Not at random But randomised  stratified sampling Qualitative assessment: Risk profiling, risk ranking


Swiss antimicrobial resistance monitoring programme : Swiss antimicrobial resistance monitoring programme Qualitative assessment Choice of antimicrobials and pathogens to investigate („hazards“) Choice of products to sample Evaluation of efficacy of sampling plan Precision of prevalence estimate Cost of sampling and analyses


Methods : Methods Data from studies on antimicrobial resistance in Switzerland Factors to be taken into account: Animal species Product type (e.g. fresh poultry, whole) Production system (e.g. organic, certified production) Geographical region Time


Risk-based sampling plan : Risk-based sampling plan Reduce random sampling and redirect sources to targeted sampling Areas for targeted sampling Areas (temporarily) exempt from sampling Areas for random sampling


Simulation model : Simulation model Compare risk-based vs. random sampling Stochastic simulation model using available data from random sampling Different sampling scenarios Find sampling plan which will result in: Best precision of prevalence estimate Best information on ‘high-risk’ products Best ratio of cost to precision of information


Exposure / consequence assessment : Exposure / consequence assessment Survival of resistant bacteria Consumption patterns, kitchen hygiene Infectious dose, severity of disease Antimicrobial treatment / treatment failure Transfer of resistance genes Causal link and quantitative estimates difficult to establish


Risk management (outlook) : Risk management (outlook) Define threshold values Define targeted intervention measures Example: >20% resistance to fluoroquinolones in Campy Information campaign on prudent use >40% resistance Restriction of drug license


Conclusions : Conclusions Scientific basis for (quantitative) risk assessment for antimicrobial resistance is still weak Risk analysis provides valuable tools to base decisions on current knowledge Interventions can be targeted to problem areas Iterative process as more scientific knowledge becomes available