To curb the development and spread of antibiotic resistance, national governments also have to recognize that this is not only a question of inappropriate antibiotic use in humans and animals.
Both antibiotics and antibiotic resistant bacteria reach the environment through several pathways (see UNDERSTAND: Antibiotic resistance – Spread of resistant bacteria and UNDERSTAND: How did we end up here? – Antibiotics in the environment), and regulatory as well as other measures are needed to diminish these pathways. Main channels include wastewater from pharmaceutical production facilities, hospitals and sewage treatment plants and manure from intensive livestock facilities. The Global Action Plan on Antimicrobial Resistance highlights the importance of increasing understanding of the impact of resistance and antibiotics in the environment, and calls for measures to control spread of resistant bacteria through the environment.
Emission from antibiotic production facilities
As pharmaceutical production facilities represent defined sources for environmental emissions of antibiotics, measures can be taken to promote resource-efficient pollution control. For example, environmental risk assessment of antibiotics should include the risk for development of antibiotic resistance in bacteria. Also, by inserting regulations for environmental control within the framework of Good Manufacturing Practice, manufacturers of medicinal products would be required to comply with specific requirements limiting discharges and emissions of active pharmaceutical ingredients into the environment, independently of in which country production is localized.
One option for governments that want to address environmental aspects of antibiotic resistance is to use sustainable public procurement. Some countries have started this work, for example by implementing environmental procurement criteria for medicines for hospital use, where emissions from manufacturing are considered. Even though discharge limits have not yet been specified, suppliers and subcontractors have to set up monitoring programs. Also, buyers of generic antibiotics could consider environmental aspects when making procurement decisions . Alternatively, environmental considerations may be included in national generic substitution systems, so that cost reduction is not the only driver in selection of therapeutically interchangeable medicines that will be reimbursed by the state.
Emissions through human use
As many antibiotics are excreted in active form through urine and feces, improved sanitation and sewage treatment is a key component to prevent the spread of resistant pathogens. Traditional sewage treatment plants are not designed for the removal of antibiotics or antibiotic resistance genes. Instead, the presence of antibiotics together with a high microbial cell density might favour resistance gene transfer between bacteria residing in activated sludge. However, the occurrence of both antibiotics and antibiotic resistant bacteria in sludge can be reduced by good management procedures such as anaerobic digestion and storage before waste solids are spread on arable land. To reduce occurrence in water effluents, different treatment options (i.e. ozonation, activated carbon filtration) should be considered. Increased attention should also be directed to hospital effluents, as it contains higher concentration of both antibiotics and antibiotic resistant bacteria than effluents from sewage treatment plants.
Lack of access to clean water and sanitation also facilitates the spread of bacterial diseases leading to increased morbidity and mortality, especially in children. The WHO-UNICEF Joint Monitoring Program for Water and Sanitation estimates that 2.4 billion people lack access to an improved sanitation facility.
Emissions through antibiotic use in animals
Use of antibiotics in the animal sector is more extensive than human usage globally, thus, emission of antibiotics into the environment from agricultural use is substantial. Limiting the general use of antibiotics is therefore, the most efficient way of also reducing the release of such compounds into the environment. As excreted antibiotics and antibiotic resistant bacteria end up in manure, they will follow the same general pattern of spread and leakage as pathogens and nutrients in manure. Regulatory measures to prevent leakage of nutrients and decrease pathogen levels, both during storage and when spread on agricultural land can therefore also have a beneficial effect on reducing antibiotics and antibiotic resistant bacteria. The prevention of nutrient leakage is also of economic interest for the farmer, as it increases the value of the manure as fertilizer, and therefore examples of good practice have been developed.
The majority of antibiotics administered to animals are excreted either as the original compound and/or as active metabolite in the feces or urine . Both resistant bacteria and antibiotic resistance genes have been found in manure. Applying manure to crop lands, therefore presents a risk for contamination of soil and surface water. However, this risk can be significantly reduced if the farmer follows a few recommendations . Reported half-lives in manure of some antibiotic classes are lower than the expected storage period of manure, suggesting that significant degradation of the parent compounds may occur prior to land application if manure is handled correctly . Awareness raising and regulatory measures to promote good practices in this field is therefore of value and recommendations have been formulated for both high- and low-income settings .
For inspiration on education and awareness campaigns, see the RAISE AWARENESS focus area.
|Management Options for Reducing the Release of Antibiotics and Antibiotic Resistance Genes to the Environment||This article discusses different options for reducing the spread of antibiotics and antibiotic resistance through the environment, and especially through agriculture. The authors identify a number of feasible option, including nutrient management, runoff control, and infrastructure upgrades.|
|Environmental procurement criteria for medicines||Procurement can be used to achieve environmental and other public policy goals. The National Agency for Public Procurement in Sweden has developed procurement criteria which encompass medical products intended for human use.|
|Antimicrobials in agriculture and the environment: reducing unnecessary use and waste||This report from the UK Review on Antimicrobial Resistance discusses the use of antibiotics in food animal production and suggests a series of policies to reduce the use of antibiotics, release into the environment and spread of antibiotic resistance. It is the fourth report on the page.|
|Antimicrobial resistance: An emerging water, sanitation and hygiene issue||Water and waste play a major role in combating antimicrobial resistance and is also an important element of the Global Action Plan. This briefing note developed by WHO provides an overview of antimicrobial resistance and WASH and proposes new directions for risk assessment management, policy and research.|