Antibiotics Use in Livestock: Implications for Human Health

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Antibiotics in foods leads to antibiotic resistance, causing super-bugs which are difficult to treat.

Antibiotics in foods leads to antibiotic resistance, causing super-bugs which are difficult to treat.

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  • Today, doctors can choose from dozens of antibiotics now on the market, and they’re being prescribed in very high numbers. At least 150 million antibiotic prescriptions are written in the United States each year.
  • These riots included shattered butcher shop windows and picket lines, but ultimately prices never changed (because they couldn’t), and primary response was to devote more research dollars to scientists to find more efficient agricultural practices.
  • Streptomycin was found to be far more powerful and useful on a larger range of diseases than Penicillin, and was specifically developed for agriculture.
  • Historically, if farmers kept too many animals in a confined space, the entire group could easily be wiped out by disease. With the development of antibiotics, factory farms naturally followed.
  • Fast forward to today. Antibiotic use in animal husbandry is known to be common, but there is a lack of data supporting exactly how much antibiotics big ag is using. Antibiotic use in food products seems to be ubiquitous. While antibiotics are still used for treatment, more commonly they are used sub-therapeutically for “routine prophylaxis” in order to combat crowding, animal stress, poor hygiene, to supplement a poor diet, and to augment premature weaning.
  • This pie graph from a NEJM commentary called “Preserving Antibiotics, Rationally” depicts the estimated distribution of antibiotic usage among humans, livestock, and other usages per kilogram sold in the United States. It illustrates the large disparity between antibiotic usage in animals and humans, although it does not differentiate between therapeutic usage and sub-therapeutic usage.
    The other chart was taken from the 2009 FDA Summary Report on Antimicrobials Sold or Distributed for Use in Food Producing Animals. It breaks down the livestock antibiotic usage by class of antibiotics. I added the blue arrows to illustrate which classes are used in humans. NIR means not independently reported, but there are at least 3 additional classes in that category that are clinically important antibiotics for human usage.
    NIR = Not Independently Reported. Antimicrobial classes for which there were less than three
    distinct sponsors actively marketing products domestically were not independently reported.
    These classes include: Aminocoumarins, Amphenicols, Diaminopyrimidines, Fluroquinolones,
    Glycolipids, Pleuromutilins, Polypeptides, Quinoxalines, and Streptogramins.
  • The more reading you do on this topic, the more you find Big Ag leaning on the techniques described in “Doubt is Their Product”. The debate surrounding antibiotic usage trends toward discussing numbers and amounts of antibiotics. How much that is used in livestock has any medical relevance to what is used in humans, who uses more per body weight, why? Etc etc. But all the focus on numbers is detracting from the real underlying problem…
  • Why exactly is non-judicious use of antibiotics in food-producing livestock a problem?
  • In short, the answer is antibiotic resistance. Just a brief overview of antibiotic resistance to make sure we are all on the same page:
    As Kismet said before, antibiotics are used to kill or stop the growth of bacteria. Antibiotics only work if the bacteria is susceptible to the drug. When antibiotics stop working, organisms become resistant to the antibiotics. This is a picture of the Kirby Bauer disk diffusion method of measure antibiotic sensitivity for bacteria. If the bacteria grow all the way up to the disk impregnated with antibiotics, the antibiotics DO NOT work for that organism.
  • This is an illustration of an organism that is developing resistance. Essentially, antibiotic therapy puts pressure the bacterial organism, causing a Darwinian survival of the fittest to happen. The antibiotics kill all the bacteria except the strongest bacteria, which might have a mutation that defeats the antibiotic. Then that single resistant bacteria is allowed to multiply, causing the whole population to become resistant.
  • The antibiotic resistance can be spread many ways. Antibiotic pressure in human treatment is a large cause of antibiotic resistance as well as human to human transmission, but resistance can come arise in other ways such as through ingestion of agricultural products that are contaminated with drug resistant bacteria.
  • There is a growing amount of scientific evidence supporting the link between agricultural antibiotic use and resistant bacteria in humans. Studies show a direct transfer of resistant bacteria between animals and humans, as well as an increase in antibiotic resistant foodborne pathogens.
  • Ultimately, this ends up being incredibly relevant due to the high morbidity and mortality and economic burden of resistant infections in humans. The problem is, how do you actually describe the cost of antibiotic resistance overall? How do you describe the cost specifically attributed to resistance linked to antibiotic usage in food producing agriculture? This tale is yet to be told, but here are some of the published estimates of the burden of resistance in general from studies which are admittedly limited in their scope.
  • http://fass.org/preservingbenefitsantibiotics.pdf
    Key considerations regarding the use of antibiotics in food animals include:
    Antibiotics are used in the care of food animals for disease treatment, disease prevention and increased production from limited feed resources.
    Feeding antibiotics to young animals is particularly effective in decreasing mortality and morbidity and thereby increasing animal welfare.
    In practice, targeted restrictions on antibiotic use have resulted in less total antibiotic use than a total blanket ban on continuous feeding of antibiotics.
    Antibiotic use in animals can lead to resistant pathogens in humans, but the extent to which antibiotic use in livestock production contributes to the overall problem is not fully understood.
    Some classes of antibiotics used in food animals are not currently used in human medicine, so elimination of their use would not be expected to affect antibiotic resistance in humans.
    Antibiotic use in food animals is strategically targeted, following judicious use guidelines based on reliable evidence developed by the American Veterinary Medical Association and other organizations.
    To decrease antibiotic use, food animal producers have implemented an impressive array of approaches to keep animals healthy and reduce the need for antibiotics, including all-in/all-out animal flow, rigorous biosecurity measures to keep diseases out of farms, intense sanitation, and vaccines.
    The world must double food production in the next 4 decades with limitations and additional inputs and judicious use of antibiotics can contribute to efficient food production to meet this demand.
  • http://fass.org/preservingbenefitsantibiotics.pdf
    Key considerations regarding the use of antibiotics in food animals include:
    Antibiotics are used in the care of food animals for disease treatment, disease prevention and increased production from limited feed resources.
    Feeding antibiotics to young animals is particularly effective in decreasing mortality and morbidity and thereby increasing animal welfare.
    In practice, targeted restrictions on antibiotic use have resulted in less total antibiotic use than a total blanket ban on continuous feeding of antibiotics.
    Antibiotic use in animals can lead to resistant pathogens in humans, but the extent to which antibiotic use in livestock production contributes to the overall problem is not fully understood.
    Some classes of antibiotics used in food animals are not currently used in human medicine, so elimination of their use would not be expected to affect antibiotic resistance in humans.
    Antibiotic use in food animals is strategically targeted, following judicious use guidelines based on reliable evidence developed by the American Veterinary Medical Association and other organizations.
    To decrease antibiotic use, food animal producers have implemented an impressive array of approaches to keep animals healthy and reduce the need for antibiotics, including all-in/all-out animal flow, rigorous biosecurity measures to keep diseases out of farms, intense sanitation, and vaccines.
    The world must double food production in the next 4 decades with limitations and additional inputs and judicious use of antibiotics can contribute to efficient food production to meet this demand.
  • HR 2932 on House side introduced
  • http://www.tufts.edu/med/apua/about_issue/antibiotic_agri.shtml
    http://healthland.time.com/2013/12/11/fda-to-farmers-no-more-antibiotics-to-fatten-up-livestock/
    Drug companies have 3 months to notify the FDA if they choose to partcipate in the new recommendation, and then have 3 years to carry out and implement the new strategies
  • http://www.nytimes.com/2013/12/12/health/fda-to-phase-out-use-of-some-antibiotics-in-animals-raised-for-meat.html?pagewanted=all&_r=1&
  • Showed no negative consequences for the farmer’s profits or animal health
    http://www.nap.edu/openbook.php?record_id=10651&page=233
  • Improving prescribing strategies
    Ex: prescribing antibiotics when they are not needed or prescribing the wrong antibiotic in outpatient settings is common
    Get Smart Program: national campaign to improve antibiotic prescribing

    http://www.cdc.gov/drugresistance/threat-report-2013/pdf/ar-threats-2013-508.pdf
  • http://www.fda.gov/ForConsumers/ConsumerUpdates/ucm349953.htm
    http://sites.psu.edu/professionalreadingblog/factors-of-antibiotic-resistance-abuseoveruse-of-antibiotics-by-humans/

Transcript

  • 1. Veronica Broslawik | Kiara Calbart Kismet Cordova | Alejandra Santisteban Colorado School of Public Health EHOH 6614 Intro to Environmental and Occupational Health 31 March 2014 Antibiotic Use In Livestock: Implications for Human Health
  • 2. History of Antibiotics
  • 3. Pre-Antibiotics • Billions of bacteria are found on our skin, in our gut, and in our mouths and throats. • Most are harmless to humans, but some are pathogenic and can cause infections. • In the early 1900s, there were no medicines to fight these common germs. As a result, the leading causes of death and disability were bacteria-related infections, including tuberculosis, pneumonia, diphtheria, strep throat, and whooping cough.
  • 4. A Legendary Discovery In the 1920’s, Alexander Fleming discovers (by accident) a fungus that kills bacteria, which came to be known as Penicillin. The term antibiotic literally means “against life”; in this case, against microbial bacteria.
  • 5. Along with sanitation, hygiene, and vaccines, antibiotics were one of the crowning public health achievements of the 20th century.
  • 6. History of Antibiotics in Agriculture
  • 7. Tough Times • Throughout the early 1900s, farmers struggled to keep up with increasing demand from urbanization. • From the late 1880s to early 1900s, the cost of groceries slowly rose (~7%/year). • Over time eggs and meat became luxury items only the upper class could regularly afford to purchase.
  • 8. As prices rose, fewer families were able to support themselves while also getting proper nutrition, and civil unrest grew. This culminated in meat counter boycotts and riots throughout the 1910s, when housewives and consumers demanded more reasonable prices and more stable meat supplies.
  • 9. Keep Them Fed! This mounting pressure on farmers remained throughout both World Wars, as they were held responsible for keeping the troops fed, as well as the usual market demands.
  • 10. An Agricultural Breakthrough • In 1943, a microbiologist named Selman Waksman (working at the New Jersey Agricultural Experiment Station) discovered a revolutionary new antibiotic, “streptomycin.” • For his discovery, Waksman received the Nobel prize for medicine in 1952.
  • 11. • Originally, antibiotics were developed to reduce disease among livestock. • Streptomycin alone cured bovine tuberculosis, a widespread problem. It also helped defeat mastitis, an infection in cow udders. • However, it was quickly discovered in general usage to vastly increase the size of animals overall, as well as the speed at which they grew. • Along with better technology, farmers were able to run much more efficiently, and prices dropped.
  • 12. A Golden Age of Meat Production • By the end of the 1940s, vitamins, proteins, antibiotics and other nutrients were all available in manufactured feeds or as additives. • The antibiotic additive market alone was worth $17.5 million. • Before, contagious diseases had limited how many animals could be held in any single flock or herd. • After antibiotics became widely available, the size of poultry, swine, and cattle feedlots rose dramatically and per-unit production costs fell.
  • 13. Antibiotics in Agriculture Today • No system that verifies the actual usage of antimicrobials in livestock. –Estimates come from sales and distribution data • Cause for Concern: overuse of antibiotics used in humans AND in livestock. • Sub-therapeutic use in livestock for “routine prophylaxis” Source: www.occupyforanimals.org
  • 14. Sources: “Preserving Antibiotics, Rationally” - Hollis & Ahmed. NEJM December 2013 FDA 2009 Summary Report on Antimicrobials Sold or Distributed for Use in Food-Producing Animals
  • 15. Source: www.fooddialogues.com www.pewhealth.org
  • 16. Why Is Antibiotic Use in Livestock a Problem?? Source: www.takepart.com
  • 17. Antibiotic Resistance • What are antimicrobials/antibiotics: – An antibiotic or an antimicrobial is a type of drug that kills or stops the growth of bacteria. • What does "susceptible" mean? – In short, it means that the antibiotic works. – “Susceptible" means that the antibiotic can kill the bacteria or stop its growth. • What is antibiotic resistance? – In short, the resistance means the antibiotic DOES NOT work. – Antibiotic resistance is the ability of bacteria to resist the effects of an antibiotic —the bacteria are not killed, and their growth is not stopped. Adapted from www.cdc.gov Frequently Asked Questions About Antibiotics and Food Safety
  • 18. Antibiotic Resistance Source: CDC Report- ANTIBIOTIC RESISTANCE THREATS in the United States, 2013 Resistant bacteria survive exposure to antibiotics and continue to multiply, potentially causing more harm and spreading to other animals or people.
  • 19. Source: CDC Report- ANTIBIOTIC RESISTANCE THREATS in the United States, 2013
  • 20. Linking Agricultural Antibiotic Use to Human Health Many types of evidence link antibiotic use in food animal production to resistant bacteria in humans. Including: •Direct studies showing resistant infections in humans coming from specific livestock operations; •Timing - Resistance in animal-associated bacteria prior to human pathogens; •Evidence linking human disease to resistance among common foodborne bacterial pathogens such as Salmonella, Campylobacter and E. coli; •Studies indicating farmers and their families may be more likely to have resistant intestinal bacteria; Source: www.wired.com
  • 21. Healthcare & Economic Burden from Antibiotic Resistance • Antibiotic resistant infections (ARIs) cost the healthcare system roughly $20 billion in 2000. • There were 900,000 cases of ARIs in 2000. • US households lost $35 billion to ARIs in 2000 o lost wages, extended hospital stays and premature deaths. • Reducing ARIs by 20% would save $3.2-5.2 billion in health care costs each year and cut up to $11.3 million in additional in-hospital days for patients with ARIs. • Estimates for cost per patient range from $18,500 to $29,000 thousand dollars. • Patients with ARIs have longer hospital stays (6-12 days longer) than patients without ARIs. Source: APUA.org/Tuft.edu The cost of antibiotic resistance to U.S.families and the health care system
  • 22. Calling for Policy Regulations
  • 23. Rationale: Antibiotic resistance in pathogens occurs too often and with increasing frequency, interfering with treatment of sick people and animals. Although antibiotics and antibiotic resistance are natural phenomena, the population of resistant bacteria is increased by introduction of antibiotics into an environment. Therefore, it is important to examine carefully the wisdom of all uses of antibiotics, in both humans and animals. Policy Statement: The Federation of Animal Science Societies (FASS) strongly supports the judicious use of antibiotics in food animal care consistent with the health and welfare of the animals, with preserving the value of antibiotics in protecting human and animal health, and with efficient use of the earth’s resources in food production. FASS: Federation of Animal Science SocietyPreserving the Benefits of Antibiotics for People and Animals
  • 24. FASS: Federation of Animal Science SocietyPreserving the Benefits of Antibiotics for People and Animals Policy Objectives: • Develop strategically targeted regulations for antibiotic use in food animals that are focused on specific risks, specific classes of antibiotics and specific uses to most effectively protect human and animal health. • Continue the use of antibiotic in food animal populations where it is demonstrably efficacious in treating disease, promoting health, and increasing global food security. • Develop regulatory systems that support use of antibiotics for disease prevention where justified.
  • 25. Environmental Defense’s role • Coalition to Keep Antibiotics Working (KAW) – Members include: ▪ Union of Concerned Scientists ▪ Humane Society of the United States ▪ National Catholic Rural Life Conference ▪ Environmental Defense • Alliance for Environmental Innovation - An arm of Environmental Defense that works with businesses to voluntarily adopt policies and practices that protect the environment.
  • 26. FDA’s Draft Guidance 152 • New FDA policy • Mostly guidance to industry for assessing NEW antimicrobial drugs for animals. • Acknowledges FDA needs to review existing approvals, but no timetable for doing so.
  • 27. Citizen Petition to FDA, March 1999
  • 28. “Preservation of Antibiotics for Medical Treatment Act” (Sen. Kennedy/Snowe; Rep. Brown/Gilchrest) ∙ Phases out nontherapeutic use of 8 classes of human-use antibiotics ➢ Unless FDA concludes ‘safe’ ∙ Ag-use data ∙ Transition support
  • 29. What Is Currently Being Done
  • 30. Currently in the United States August 2013: FDA recommends a strategy for more appropriate use of antibiotics ● Re-labeling of drug products to remove the claims of growth promotion, and instead highlight the more appropriate use for prevention, control, and treatment of bacterial diseases ● Require veterinarians to prescribe and issue the drugs, rather than the antibiotics being available over the counter ● Voluntary participation for drug companies
  • 31. What Could Be Done?
  • 32. More Drastic Recommendations • Farmers could substitute the use of antibiotics for vaccines, although this option is more expensive • Only use the antibiotics that are not used for humans • International agreement – Antibiotic resistance knows no borders! • Ban the use of antibiotics claimed to be for the prevention of disease • Limit the use to the specific treatment of a disease, only after being prescribed by a veterinarian
  • 33. The European Union • Current policy in the United States differs from policy in the European Union which in 2006 banned the use of antimicrobials claiming to promote animal growth • Denmark: in 1998, four growth promoters were banned – Resulted in a 60% decrease in the use of antibiotics for growth promotion • Netherlands: inappropriate antibiotic use declined only after limits on total use were placed, and fines were issued for noncompliance
  • 34. Public Health Recommendations
  • 35. CDC’s Work to Prevent Antibiotic Resistance • Systems to track resistant infections and changes in resistance trends • Improving prescribing strategies. – Get Smart program – At least 50% of antibiotics prescribed are not needed • Limiting the spread of infections – Vaccinations – Effective treatment guidelines • The CDC encourages efforts to minimize the inappropriate use of antibiotics in animals.
  • 36. What Can Consumers Do? • Take antibiotics exactly as directed – Always finish the full regimen. – Never take leftover antibiotics from a previous illness • Do not demand antibiotics for viral infections: – WHO states that 85% of patients thought their respiratory symptoms were bacterial, and in 75% of these cases, doctors prescribed antibiotics unnecessarily. • Reduce meat consumption
  • 37. References• http://www.cdc.gov/mmwr/preview/mmwrhtml/mm4829a1.htm • http://www.healthychildren.org/English/health-issues/conditions/treatments/pages/The-History-of-Antibiotics.aspx • http://news.bbc.co.uk/2/hi/health/background_briefings/antibiotics/163997.stm • http://textbookofbacteriology.net/themicrobialworld/medical.html • http://blogs.scientificamerican.com/guest-blog/2013/09/03/riots-rage-and-resistance-a-brief-history-of-how-antibiotics- arrived-on-the-farm/ • https://microbewiki.kenyon.edu/index.php/Antibiotic_Use_for_Farm_Animals • http://tenement-museum.blogspot.com/2012/04/what-other-half-paid-part-one.html • http://www.livinghistoryfarm.org/farminginthe40s/crops_09.html • http://www.tufts.edu/med/apua/about_issue/antibiotic_agri.shtml • http://www.sciencedaily.com/releases/2013/12/131226115348.htm • http://www.nytimes.com/2013/12/12/health/fda-to-phase-out-use-of-some-antibiotics-in-animals-raised-for- meat.html?pagewanted=all&_r=1& • http://www.cdc.gov/drugresistance/threat-report-2013/pdf/ar-threats-2013-508.pdf • http://www.nap.edu/openbook.php?record_id=10651&page=233 • http://www.fda.gov/ForConsumers/ConsumerUpdates/ucm349953.htm • http://sites.psu.edu/professionalreadingblog/factors-of-antibiotic-resistance-abuseoveruse-of-antibiotics-by- humans/