neighbours after chickens receiving an antibiotic in their feed. manure may also be contain antibiotic-resistant staphylococcus aureus bacteria which can infect humans. in 2017, the who included methicillin-resistant s. aureus (mrsa) in its priority list of 12 antibiotic-resistant bacteria, urging the need to search for new and more effective antibiotics against it. there also has been an increase in the number of bacterial pathogens resistant to multiple antimicrobial agents, including mrsa, which have recently emerged into different lineages. some of them are associated with livestock and companion animals that are then able to be transmitted to humans, also called livestock-associated methicillin-resistant staphylococcus aureus (la-mrsa). these new lineages can be found on soft tissues of livestock workers, for example in their noses. a study looked at the association between exposure to livestock and the occurrence of la-mrsa infection and observed that la-mrsa infection was 9.64 times as likely to be found among livestock workers and veterinarians compared to their unexposed families and community members, showing that exposure to livestock significantly increases the risk of developing mrsa infection. although total numbers colonised by la-mrsa remain low, and fewer still develop infection, the condition is nonetheless rising in prevalence, difficult to treat, and has become a public health concern. foodborne antibiotic resistance another way humans can be exposed to antibiotic-resistant bacteria is by pathogens on food. in particular, if resistant bacteria are ingested by humans via food and then colonise the gut, they can cause infections which are unpleasant enough in themselves, but can be even harder to treat if they are serious enough to require antibiotic treatment but are also resistant to commonly-used antibiotics. campylobacter, salmonella, e. coli and listeria species are the most common foodborne bacteria. salmonella and campylobacter alone account for over 400,000 americans becoming sick from antibiotic-resistant infections every year. dairy products, ground minced beef and poultry are among the most common foods that can harbour pathogens both resistant and susceptible to antibiotics, and surveillance of retail meats such as turkey, chicken, pork and beef have found enterobacteriaceae. while some studies have established connections between antibiotic resistant infections and food-producing animals, others have struggled to establish causal links, even when examining plasmid-mediated resistance. standard precautions such as pasteurising, or preparing and cooking meat properly, food preservation methods, and effective hand washing can help eliminate, decrease, or prevent spread of and infection from these and other potentially harmful bacteria. other sources of resistance as well as via food, e. coli from a variety of sources can also cause urinary and bloodstream infections. while one study suggests a large proportion of resistant e. coli isolates causing bloodstream infections in people could emanate from livestock produced for food, other studies have since contradicted this, finding little commonality between resistance genes from livestock sources and those found in human infections, even when examining plasmid-mediated resistance. the use of antibiotics in livestock also has the potential to introduce antibiotic-resistant bacteria to humans via environmental exposure or inhalation of airborne bacteria. antibiotics given to livestock in sub-therapeutic concentrations to stimulate growth when there is no diagnosis of disease – a practice still permitted in some countries – may kill some, but not all, of the bacterial organisms in the animal, possibly leaving those that are naturally antibiotic-resistant in the environment. hence the practice of using antibiotics for growth stimulation could result in selection for resistance. antibiotics are not fully digested and processed in the animal or human gut, therefore, an estimated 40–90% of the antibiotics ingested are excreted in urine and/or faeces. this means that as well as finding antibiotics in human sewage and animal manure, both can also contain antibiotic-resistant bacteria which have developed in vivo or in the environment. when animal manures are stored inadequately or applied as fertiliser, this can then spread bacteria to crops and into run-off water. antibiotics have been found in small amounts in crops grown in fertilised fields, and detected in runoff from animal waste-fertilised land. composting has been shown to reduce the presence of various antibiotics by 20–99%, but one study found that chlortetracycline, an antibiotic used in livestock feed in china, degraded at different rates dependent on the animal it was fed to, and that manure composting was not sufficient to ensure the microbial degradation of the antibiotic. global positions on antibiotic use in farm animals in 2017, the world health organization (who) recommended reducing antibiotic use in animals used in the food industry. due to the increasing risk of antibiotic resistant bacteria, the who strongly suggested restrictions on antibiotics being used for growth promotion and antibiotics used on healthy animals. animals that require antibiotics should be treated with antibiotics that pose the smallest risk to human health. hsbc also produced a report in october 2018 warning that the use of antibiotics in meat production could have "devastating" consequences for humans. it noted that many dairy and meat producers in asia and the americas had an economic incentive to continue high usage of antibiotics, particularly in crowded or unsanitary living conditions. however, the world organisation for animal health has acknowledged the need to protect antibiotics but argued against a total ban on antibiotic use in animal production. a total ban on antibiotics might drastically reduce protein supply in some parts of the world, and when use of antibiotics is reduced or eliminated in livestock through legislation or voluntarily, both animal health and welfare and economic impacts can be negatively affected. for example, experiences from farms where antibiotic use has been cut back or eliminated in the interests of meeting a consumer demand for 'antibiotic-free' or 'reared without antibiotics' produce have been shown to have a detrimental effect on animal health and welfare. when antibiotics are used sub-therapeutically (for animal performance, increased growth, and improved feed efficiency), then the costs of meat, eggs, and other animal products are lowered. one big argument against the restriction of antibiotic use is the potential economic hardship that would result for producers of livestock and poultry that could also result in higher cost for consumers. in a study analysing the economic cost of the fda restricting all antibiotic use in animal livestock, it was estimated that the restriction would cost consumers approximately $1.2 billion to $2.5 billion per year. in order to determine the overall economic impact of restricting antibiotic use, the financial cost must be weighed against the health benefits to the population. since it is difficult to estimate the value of potential health benefits, the study concluded that the complete economic impact of restricting antibiotic use has not yet been determined. although quantifying health benefits may be difficult, the economic impact of antibiotic restriction in animals can also be evaluated through the economic impact of antibiotic resistance in humans, which is a significant outcome of antibiotic use in animals. the world health organization identifies antibiotic resistance as a contributor to longer hospital stays and higher medical costs. when infections can no longer be treated by typical first-line antibiotics, more expensive medications are required for treatment. when illness duration is extended by antibiotics resistance, the increased health care costs create a larger economic burden for families and societies. the center for infectious disease research and policy estimates approximately $2.2 billion in antibiotic resistance- related healthcare costs each year. so while restricting antibiotics in animals causes a significant economic burden, the outcome of antibiotic resistance in humans that is perpetuated by antibiotic use in animals carries comparable economic burdens. use and regulation by country antibiotic use in livestock world map (2010) does livestock antibiotic use exceed suggested target? (2010) the use of medicines to treat disease in food-producing animals is regulated in nearly all countries, although some countries prescription-control their antibiotics, meaning only qualified veterinary surgeons can prescribe and in some cases dispense them. historically, the restrictions have existed to prevent contamination of mainly meat, milk, eggs and honey with chemicals that are in any way harmful to humans. treating a sick animal with medicines may lead the animal product containing some of those medicines when the animal is slaughtered, milked, lays eggs or produces honey, unless withdrawal periods are adhered to which stipulate a period of time to ensure the medicines have left the animal's system sufficiently to avoid any risk. scientific experiments provide data for each medicine in each application, showing how long it is present in the body of an animal and what the animal's body does to metabolise the medicine. by the use of 'drug withdrawal periods' before slaughter or the use of milk or eggs from treated animals, veterinarians and animal owners ensure that the meat, milk and eggs is safe and free of any contamination. however, some countries have also banned or heavily controlled routine use of antibiotics for growth stimulation or the preventative control of disease arising from deficiencies in management or facilities. this is not over concerns about residues, but about the growth of antibiotic resistance. brazil brazil is the world's largest exporter of beef. the government regulates antibiotic use in the cattle production industry. canada because of concerns about antibiotics residues getting into the milk or meat of cattle, the canadian food inspection agency (cfia) enforces standards which protect consumers by ensuring that foods produced will not contain antibiotics at a level which will cause harm to consumers. in canada the veterinary drug regulation consists of two federal government agencies, namely health canada and the cfia, which are responsible for implementing and enforcing the food and drugs act. testing samples for drug residues include three methods: monitoring, surveillance, and compliance. there are swab test on premises (stop) procedures to detect antibiotic residues in kidney tissues. china china produces and consumes the most antibiotics of all countries. antibiotic use has been measured by checking the water near factory farms in china as well as through animal faeces. it was calculated that 38.5 million kg (or 84.9 million lbs) of antibiotics were used in china's swine and poultry production in 2012. the abuse of antibiotics caused severe pollution of soil and surface water in northern china. in 2012, u.s. news & world report described the chinese government's regulation of antibiotics in livestock production as "weak". on the uk 5-year antimicrobial resistance (amr) strategy 2013–2018, the importance of addressing amr negative effects on animal health has been considered as same as human health. several scientific partnerships with low-middle income countries would be established. uk-china newton fund has started to build multi-discipline collaboration cross the border to stop the increasing global burden caused by amr. to achieve the goal of citizen public health and food safety, "the national action plan on controlling antibiotic-resistance bacteria on animal origins (2016–2020)" has been published by ministry of agriculture and rural affairs of people's republic of china since 2017. this plan is fully integrated with the concept of one health. it covers not only the research and development, but also social context. european union antibiotic use in livestock in europe in 1999, the european union (eu) implemented an antibiotic resistance monitoring program and a plan to phase out antibiotic use for the purposes of growth promotion by 2006. the european union banned the use of antibiotics as growth agents starting on 1 january 2006 with regulation (ec) no 1831/2003. in germany, 1,734 tons of antimicrobial agents were used for animals in 2011 compared with 800 tons for humans. sweden banned their use in 1986 and denmark started cutting down drastically in 1994, now using 60% less. in the netherlands, the use of antibiotics to treat diseases increased after the ban on its use for growth purposes in 2006. in 2011, the european parliament voted for a non-binding resolution that called for the end of the preventative use of antibiotics in livestock. a revised regulation on veterinary medicinal products, proposed in procedure 2014/0257/cod, proposed limiting the use of antibiotics in prophylaxis and metaphylaxis. an agreement on the regulation between the council of the european union and the european parliament was confirmed on 13 june 2018, and the new veterinary medicines regulation (regulation (eu) 2019/6) is due to come into effect on 28 january 2022. india in 2011 the indian government proposed a "national policy for containment of antimicrobial resistance". other policies set schedules for requiring that food producing animals not be given antibiotics for a certain amount of time