Upload
john-blue
View
64
Download
4
Embed Size (px)
Citation preview
Antibiotic use in the swine industry Where is it at, and where is it going?
Peter DaviesUniversity of Minnesota
Carlos Pijoan Lecture
Resistance to medically important antibiotics has been generated in animals…
… and is spread to humans with the potential to cause major harm and we..
Must take action to minimize it!
…but the evidence that it has spread to humans and caused major harm is minimal or non-existent and..
No action is required!
2
The Antibiotic Resistance Crisis
Antibiotics are ‘miracle’ drugs Efficacy of antibiotics is declining Medicine and agriculture have evolved with antibiotics Modern medicine is dependent on antibiotic use
Surgery, transplants, chemotherapy,……… A tribute to medical advancement
Modern agriculture is dependent on antibiotic use A condemnation of agricultural practices
This week in Antibiotic Resistance
FAO action plan on antibiotics in food production FDA call for comment on antibiotics without defined duration Citizen petition to FDA to withdraw medically important
antibiotics for disease prevention and growth promotion UK Food Systems Agency pledge to reduce use in food animals Detailed Dutch report on antibiotic use in food animals PACCARB meeting in DC UN General Assembly ‘high-level meeting’ Sep 21 >60 new peer reviewed publications 421,300 web postings
3,090 news items
The ruling consensus?
Antibiotic use in food animals is a global issue associated with public health
All countries should use antibiotics in food animals more prudently
Time to act globally to restrict or prohibit the use of antibiotics in feed for the purpose of growth promotion or disease prevention
Dr. Jianzhong Shen
‘Idealism increases in direct proportion to one’s distance from the problem’
John GalsworthyNobel Prize in Literature 1932
National Pork Board 2015 Prioritized vulnerabilities
1. Antibiotics2. Foreign animal disease3. Market preparedness4. Ethics of pork production5. Dietary guidelines
European antibiotic experiencesPhilosophy
1969 1987 2000 2006 2011
Vancomycin R Enterococci, Salmonella DT104, FQ R Campy., LA-MRSA, ESBL, CRE, mcr-1…..
Jan1, 2000 Jan1, 2017
January 1, 2017
The veterinary profession has been handed the football
January 1, 2017
We are playing in a new stadium
The spectrum of defensibility
Growth promotion/OTC not philosophically defensible regardless of evidence of harm
Defense of disease prevention and control will require evidence of benefit to animal health and welfare
Individual treatment of clinically affected pigs
Batch medicationof healthy and affected pigs in outbreaks
‘Production” Uses
‘Routine’ preventivemedication of ‘at risk’ pigs
What really matters? Are we doing harm, and how much? How do we use antibiotics in the swine industry?
What is effective? What is necessary? What is philosophically defensible?
How good is the evidence? Harm to public health Benefits to animal health and food safety How best to use antibiotics in food animals
Can we do better?13
The resistance crisis and food animalsWhat are we talking about?
All organisms/ genes great and small
Vague and not specific
Specific pathogens and antibiotics
Known public health impact
Specific pathogens and antibiotics
Equivocal public health impact
Antibiotic resistance threats in the USA(CDC, Am Fam Physician. 2014 Jun 15;89(12):938-941.)
Urgent• Clostridium difficile • Carbapenem-resistant
Enterobacteriaceae • Drug-resistant N. gonorrhea Concerning• Vancomycin-resistant S. aureus• Erythromycin-resistant group A
Streptococcus • Clindamycin-resistant group B
Streptococcus
Serious• Multidrug-resistant Acinetobacter • Drug-resistant Campylobacter • Fluconazole-resistant Candida • ESBL–producing Enterobacteriaceae • Vancomycin-resistant Enterococcus • MDR Pseudomonas aeruginosa • Non-typhoidal Salmonella • Salmonella serotype Typhi • Drug-resistant Shigella • MRSA• MDR Streptococcus pneumoniae • Drug-resistant tuberculosis
Urgent• Clostridium difficile • Carbapenem-resistant
Enterobacteriaceae
Concerning• Vancomycin-resistant S. aureus••
Serious• Multidrug-resistant Acinetobacter • Drug-resistant Campylobacter
• ESBL–producing Enterobacteriaceae • Vancomycin-resistant Enterococcus
• Non-typhoidal Salmonella
MRSA
Antibiotic resistance threats in the USAFoodborne
Relative rates of culture-confirmed infections with Campylobacter, STEC* O157, Listeria, Salmonella, Vibrio, and Yersinia, compared with 1996–1998 rates
FoodNet 1996–2015
• ~20-30% reduction in Listeria, Campylobacter, STEC O157• ~ 0% change in Salmonella • ~60% reduction in Yersinia enterocolitica (swine related)
% of ‘non typhoid’ Salmonella resistantto >3 classes of antibiotics (NARMS 2013)
17%
9.8%
MDR more prevalent in in food animal reservoir
Urgent• Clostridium difficile • Carbapenem-resistant
Enterobacteriaceae
Concerning
Serious• Multidrug-resistant Acinetobacter • Drug-resistant Campylobacter
• ESBL–producing Enterobacteriaceae • Vancomycin-resistant Enterococcus
• Non-typhoidal Salmonella
• MRSA• Colistin resistant Enterobacteriaceae
Antibiotic resistance threats in the USAFoodborne and/or livestock reservoir
Antibiotic resistant bacteria linked to livestock - driving the discussion
Vancomycin resistant enterococci (VRE) ‘Livestock associated’ MRSA ESBL Enterobacteriaceae Colistin resistant (mcr-1) Enterobacteriaceae Carbapenem resistant Enterobacteriaceae
Avoparcin and VRE in Europe
Avoparcin: glycopeptide (vancomycin related) antibiotic used for growth promotion in Europe from early 1970s Never licensed in the USA
VRE in Europe in 1990s High prevalence in pigs and poultry (avoparcin) ~10% prevalence of VRE carriage in healthy humans VRE clinical infections remained rare
Sparse use of vancomycin in human medicine Avoparcin banned in EU in 1990s (all by 1997)
Vancomycin use in human medicine in USA vs. Europe (Bonten et al., 2001)
Prevalence of VRE in nosocomial infections in intensive-care patients in
the USA (Bonten et al., 2001)
Vancomycin resistance E. faecium bacteremias in North America and Europe
(1999-2008 SENTRY Program)
(April 1, 1997 as a precautionary, protective measure)
Avoparcin and VRE
Avoparcin use led to high VRE prevalence in food animals and healthy humans
VRE infections in USA attributed to high use of vancomycin in human medicine No glycopeptide antibiotic use in food animals
VRE infections emerged in Europe several years after the banning of avoparcin
ST398 ‘Livestock associated’ MRSA Generally accepted ‘facts’
First recognized in Netherlands in 2004 Now reported in livestock species in many countries
High exposure risk for people with animal contact 20-50% vs. ~ 0.5 - 2% in general populations
Human clinical cases reported, some serious Very few serious infections in healthy livestock workers Several deaths (~10 in > 10 years) in medically
compromised people Low risk of exposure for the general public
Emergence of ST398 MRSA infections in people in Denmark
Larsen et al. (Euro Surveill. 2015)
CC398 ‘has become a major cause of human disease in Europe, posing a serious public health challenge in countries with intensive livestock production’
Suggests substantial dissemination of MRSA CC398 from livestock or livestock workers into the Danish community
Findings strongly suggest foodborne transmission does not play a major role in the MRSA CC398 epidemiology
Incidence of MRSA infections in DK in 2011 (Larsen et al., 2015)
Pig dense areas All MRSA
10.9/100,000 person-years
ST398 (no pig contact) 0.7/100,000 person-years
Other areas All MRSA
12.8/100,000 person-years
ST398 (no pig contact) 0.3/100,000 person-years
LA-MRSA in the USA
Prevalence of LA-MRSA relatively low in US swine ST398, ST5, ST9 (Smith 2013, Sun 2015)
Carriage of ST398 MRSA in IA the same (2-3%) in people exposed and not exposed to pigs (Wardyn, 2015)
but increased exposure to LA-MSSA variants (MDR)
Study of human laboratories in IA (Nair, 2016)
LA-MRSA found in 0.24% of MRSA cases LA-MSSA ~ 1% of S. aureus infections
What we know about antibiotic use (ABU)
ABU selects for resistance in any setting The contribution of ABU in animals is to resistance
in human pathogens is >0 Lack of ‘proof’ of harm is not an argument for
‘injudicious’ use Greater abuse in other places is not an argument
for ‘injudicious’ use Room for improved stewardship of antibiotics in
food animal industries
True or false?
USDA residue monitoring data show that >13% of market hogs had violative antibiotic residues?
TRUE!
In 1978
2014 National Residue Program
Scheduled testing (ST) – all species 10 of 6,021 (0.17%) animals had violative residues 8 veal calves, 1 cow, 1 sheep
Market hogs 0 of 774 ST hogs had violative residues 8 (0.05%) hogs of 17,354 ‘inspector generated’ hogs
We have come a long way!
34
35
As we move forward as a society we create more problems
Higher economic growth and consumerism lead to more stress as people work more and society falls behind
The more we know, the more we have to discover The better things become, the worse they are
perceived
Paradox of Progress
It does not make sense to delay action further: the burden of proof should be for those who oppose curtailing the use of antimicrobials in food production to explain why, not the other way around
Antibiotics are …a shared societal trust or property. It is not acceptable for one group of people to abuse this trust for the purpose of perceived economic advantage, while harming everyone else
Many parties promote the routine use of antibiotics in livestock specifically because they perceive (possibly incorrectly) that it enables the meat, poultry, and drug industries to maximize production and profits
Thus, a group of people in society are using antibiotics injudiciously to mask inferior management practices for perceived gains in short-term profits, contributing to the spread of antibiotic-resistant bacteria to other people in society
How good is antibiotic stewardship in the swine industry?
How bad ‘they’ say we are
How good we say we are
?
Can you manage it if you don’t measure it?
>50% reduction in use associated with reduced resistance in commensals of broilers, veal calves and pigs
(modified from Dr. C. Bruschke)
3Source: Veterinary Medicines Authority: Relaties tussen antibioticagebruik en voorkomen van resistente micro-organismen (february 2016) www.sda.nl
Calls to measure antibiotic use in food animals
WHO policy to standardize ABU surveillance of antibiotic use in humans and animals
EU directive to harmonize ABU surveillance across countries as part of an Action Plan
EU countries (DK, NL, BE, DE,..) benchmark ABU at farm/vet level Consumer groups/ politicians seeking stricter regulation and
monitoring of antibiotic use in food animals Demands from downstream customers for assurances related to
judicious antibiotic use in the supply chain National Action Plan for Combatting Antibiotic Resistant Bacteria
National Action Plan to Combat Antibiotic Resistant Bacteria
1. Slow the Development of Resistant Bacteria and Prevent the Spread of Resistant Infections
2. Strengthen National One-Health Surveillance Efforts to Combat Resistance
3. Advance Development and Use of Rapid and Innovative Diagnostic Tests for Identification and Characterization of Resistant Bacteria
4. Accelerate Basic and Applied R&D for New Antibiotics, Other Therapeutics, and Vaccines
5. Improve International Collaboration and Capacities for Antibiotic Resistance Prevention, Surveillance, Control, and Antibiotic Research and Development
1.3 Identify and implement measures to foster stewardship of antibiotics in animals.
2.4. Enhance monitoring of antibiotic-resistance patterns, as well as antibiotic sales, usage, and management practices, at multiple points in the production chain from food-animals on-farm, through processing, and retail meat.
ii. Enhance collection and reporting of data regarding antibiotic drugs sold and distributed for use in food-producing animals.iii. Implement voluntary monitoring of antibiotic use and resistance in pre-harvest settings to provide nationally-representative data while maintaining producer confidentiality.
Measurement - steps forward
FDA/USDA initiatives under NAP not funded Voluntary programs? ‘Barnyard’ group meetings (2015/2016)
Dairy, beef, broilers, turkeys, layers, swine
Major issues Metrics, Confidentiality, Representativeness Buy-in
Market driven initiatives
NPB initiatives
Increased funding for AMR/AMU research Sabbatical project
Task force on measurement of antibiotic use Purpose: define current practices for
benchmarking and to support stewardship efforts Proposed pilot project in growing pigs
5-10 systems Confidentiality Metrics
Looking forward
Increasing scrutiny Continuous improvement
Systems of production Use of antibiotics
Measurement of use Evidence-based for treatment regimens
Prevention – Control – Treatment Drug – route – dose – duration Animal health and food safety
So, therefore, is the future