Viewpoint pubs.acs.org/est
Antibiotic Stewardship Should Consider Environmental Fate of Antibiotics Emma J. Rosi-Marshall*,† and John J. Kelly‡ †
Cary Institute of Ecosystem Studies, Millbrook, New York 12545, United States Department of Biology, Loyola University Chicago, Chicago, Illinois 60626, United States key component of a national strategy to improve antibiotic stewardship. The use of antibiotics in livestock has been recognized as contributing to the release of antibiotics to the environment,2 and the National Action Plan does propose to “eliminate the use of medically-important antibiotics for growth promotion in food-producing animals and bring other agricultural uses of antibiotics··· under veterinary oversight”. This proposal should help to reduce antibiotic release from agriculture. However, a less well recognized issue, which was not mentioned in the National Action Plan or the PCAST report, is the contribution of our nation’s deteriorating sewage infrastructure to the environmental release of antibiotics. We propose that addressing this deteriorating infrastructure should be an explicit part of a national strategy for antibiotic stewardship. Although we focus herein on conditions in the U.S., the principle that environmental fate should be a component of antibiotic stewardship is relevant throughout the world. More than 250 million antibiotic prescriptions are written in the U.S. each year,3 and antibiotics are not entirely processed via human metabolism. This results in the release of antibiotics in human waste, and research presented in ES&T has ntibiotic-resistant bacterial infections are a significant documented the presence of antibiotics in wastewater public health issue, and contribute to at least 23 000 throughout the world. In the U.S., many consumers also deaths and at least 2 million serious illnesses in the U.S. each dispose of unwanted or expired medications by flushing them year.1 In March 2015 the White House released the National down the toilet, despite advice to the contrary. Thus, antibiotics Action Plan for Combating Antibiotic-Resistant Bacteria, which end up in wastewater, and in the US 32 billion gallons of this was developed in response to an Executive Order on wastewater flows through 700 000 miles of underground pipes Combating Antibiotic-Resistant Bacteria issued by President and canals to treatment plants each day.4 Unfortunately, not all Barack Obama. The National Action Plan addresses policy of this sewage reaches its intended destination. In the U.S., much of the network of sewage pipes was installed just after recommendations contained in a recent Report to the President World War II, some as far back as the late 1800s. These pipes on Combating Antibiotic Resistance prepared by the President’s are showing signs of age, and many are leaking. The American Council of Advisors on Science and Technology (PCAST). Society of Civil Engineers recently gave the U.S. sewage The National Action Plan seeks to address the challenge of infrastructure a grade of “D”.4 The EPA has projected that the antibiotic resistance through enhanced surveillance, improved percentage of U.S. wastewater pipes in “poor,” “very poor,” or international collaborations, the development of new anti“life-elapsed” conditions will increase from 23% in 2000 to 45% biotics, and improved antibiotic stewardship. The PCAST in 2020.5 In the U.S., an estimated 900 billion gallons of sewage report defines antibiotic stewardship as “efforts to optimize the is released into the nation’s rivers and streams each year via use of antibiotics” and presents strategies to improve antibiotic infrastructure leaks or combined sewage overflows.4 stewardship in human health care and animal agriculture. Due to a variety of factors, including antibiotic use in We note, however, that the National Action Plan and the agriculture and antibiotic release via treated wastewater effluent PCAST report do not include the environmental fate of or unintentional release via failing infrastructure, antibiotics are antibiotics as a component of antibiotic stewardship, nor do present in surface waters throughout the U.S. The abundance they address the increasing concentrations of antibiotics in U.S. of antibiotic-resistant bacteria as well as the abundance of surface waters as a potential contributing factor to the rise in antibiotic resistance genes have been linked to the presence of antibiotic resistance. As more evidence continues to mount that antibiotics in the environment may be contributing to the development and spread of antibiotic-resistant microbes, we Received: April 2, 2015 Published: April 23, 2015 propose that the environmental fate of antibiotics should be a ‡
A
© 2015 American Chemical Society
5257
DOI: 10.1021/acs.est.5b01519 Environ. Sci. Technol. 2015, 49, 5257−5258
Viewpoint
Environmental Science & Technology antibiotics in rivers, leading to growing concern that the unintended release of antibiotics to surface waters may be contributing to the development of antibiotic-resistant bacteria and the spread of antibiotic resistance genes among bacterial taxa via horizontal gene transfer. Moreover, work by our team and others has demonstrated the potential for antibiotics in rivers to alter rates of microbially-driven ecosystem processes, including primary production and respiration, suggesting that antibiotics may pose risks to the overall health of aquatic ecosystems. Antibiotic stewardship needs to extend beyond the development of new antibiotics and controlling the use of antibiotics by people and livestock. Antibiotic stewardship must also consider the ultimate fate and consequences of antibiotics in the environment, and should specifically address the environmental release of antibiotic residues. Repairing our crumbling infrastructure is a logical place to start and will address multiple environmental issues associated with the release of untreated effluent, including the release of antibiotics. It is time to invest in our future and keep our untreated wastes, including antibiotics, out of the environment. Over the next 20 years, the EPA estimates that it will cost $300 billion to upgrade our deteriorating sewage systems, and yet the U.S. Congress has allocated just $2 billion per year to deal with this problem, less than 14% of the funds needed.4 Repairing infrastructure, cutting leaks, and upgrading sewage systems should be both a local and national priority for human and environmental health. Investing in this infrastructure will help preserve antibiotic effectiveness and ensure the health of freshwater ecosystems. Maintenance of infrastructure has too often been left to the future, with compounding negative effects. We can do better. Further, we suggest that support for research investigating the links between release of antibiotics to the environment, antibiotic resistance in the environment, and human and ecosystem health should be a national priority. This should be done in combination with the support for research to develop new antibiotics, to ensure the effectiveness of antibiotics long into the future.
■
AUTHOR INFORMATION
Corresponding Author
*E-mail:
[email protected]. Notes
The authors declare no competing financial interest.
■
REFERENCES
(1) Centers for Disease Control and Prevention. 2013. Antibiotic Resistance Threats in the United States. http://www.cdc.gov/ drugresistance/threat-report-2013/pdf/ar-threats-2013-508.pdf. (2) Sarmah, A. K.; Meyer, M. T.; Boxall, A. B. A global perspective on the use, sales, exposure pathways, occurrence, fate and effects of veterinary antibiotics (VAs) in the environment. Chemosphere 2006, 65 (5), 725−759. (3) Hicks, L. A.; Taylor, T. H., Jr; Hunkler, R. J. US outpatient antibiotic prescribing, 2010. N. Engl. J. Med. 2013, 368 (15), 1461− 1462. (4) American Society of Civil Engineers. 2013. Report card for America’s infrastructure. http://www.infrastructurereportcard.org/a/ #p/drinking-water/overview. (5) United States Environmental Protection Agency. 2002. The clean water and drinking water infrastructure gap analysis. http://www.epa. gov/ogwdw/gapreport.pdf.
5258
DOI: 10.1021/acs.est.5b01519 Environ. Sci. Technol. 2015, 49, 5257−5258
