Since their introduction perhaps 80 to 90 years ago, antibiotics have revolutionized the practice of medicine worldwide. However antimicrobial resistance (AMR) threatens to impede or even reverse some of this progress. In the U.S. resistant organisms cause 2 million infections and are associated with 23,000 deaths each year. In Europe they cause 25,000 deaths per year. The costs of AMR are quite substantial and are estimated to be responsible for $20 billion in excess medical spending in the US each year. Today I would like to delve into the reasons for AMR and what is being done about it.
In the U.S. antibiotic use in animals raised for food accounts for 80 percent of total antibiotic use. Of that 80 percent, 74 percent is added to feed to promote animal growth. Human consumption of animal products from animals given antibiotics has been directly linked to AMR in humans. The influence of agricultural use of antibiotics on human health has drawn a number of responses. Most European countries have banned the use of antibiotics to promote animal growth. Here the FDA requires producers of animal drug products to report annually the amount of products sold. The FDA also encourages food providers to voluntarily reduce antibiotic use but the FDA does not ban their use.
Human antibiotic use also contributes to the emergence of AMR. Most hospitals have antibiotic stewardship programs which often restrict the use of certain antibiotics and require Infectious Disease specialist approval for the restricted drugs. Outpatient care settings, and particularly primary care offices, are another area of concern. Studies have shown that when they were given counseling and education antibiotic prescriptions from primary care practitioners dropped considerably. Patients themselves can also be problematic. Many patients will go to their doctor seeking antibiotics for minor, and often viral, infections and, if given antibiotics, many will not take them as prescribed or shorten the length of treatment themselves. This leads to AMR. Direct-to-consumer advertising also often contributes to the problem by causing patients to seek treatment with products which would be inappropriate in their case.
The rate at which new antibiotics are being introduced has slowed considerably. Between 1983 and 1987 the FDA approved 12 new antibiotics while between 2008 and 2012 only 2 were approved. Since 2012 5 were approved. Many manufacturers have left the antibiotic research and development field because of low prices, restrictions on use by hospitals and others, and rapid development of resistance. Research is being done on other tactics to fight AMR such as harnessing the human immune system, manipulating microbial communities such as the human gut, vaccines, and antivirulence strategies. The latter strategy attacks factors within the bacterium without killing it, thereby allowing the altered (less resistant) bacterium to spread its alterations to other germs rendering them more susceptible to antimicrobial drugs. Meanwhile both public and physician education will continue otherwise the postantibiotic age predicted by many will become a distinct and unwelcome possibility.