EVERY year, more than 2 million people in the U.S. get infections that are resistant to antibiotics, and at least 23,000 people die as a result, according to a new report issued by the Centers for Disease Control & Prevention (CDC).
The report, "Antibiotic Resistance Threats in the United States, 2013," presents the "first snapshot" of the burden and threats posed by antibiotic-resistant microbes that have the most impact on human health, CDC said.
Threats were assessed according to seven factors associated with resistant infections: health impact, economic impact, how common the infection is, a 10-year projection of how common it could become, how easily it spreads, availability of effective antibiotics and barriers to prevention.
"Antibiotic resistance is rising for many different pathogens that are threats to health," CDC director Tom Frieden said.
According to CDC, the use of antibiotics is the single-most important factor leading to antibiotic resistance. The agency noted that up to 50% of all antibiotics prescribed to people are not needed or are not prescribed appropriately.
Antibiotics are also commonly used in food-producing animals to prevent, control and treat disease and to promote growth, CDC said, adding that it is important to use antibiotics in animals responsibly.
To help ensure that medically important antibiotics are used judiciously in food-producing animals, CDC pointed out that the Food & Drug Administration recently proposed a guidance describing a pathway for using these drugs only when medically necessary and targeting their use to only address diseases and health problems.
Four core actions
To combat the development of antibiotic resistance, CDC has identified four core actions:
1. Preventing infections and preventing the spread of resistance. Avoiding infections reduces the amount of antibiotics that have to be used and reduces the likelihood that resistance will develop, CDC said. Drug-resistant infections can be prevented by immunization, infection prevention actions in health care settings, safe food preparation and handling and general hand washing.
2. Tracking. CDC gathers data on antibiotic-resistant infections, causes of infections and whether there are particular reasons (risk factors) that cause some people to get a resistant infection.
3. Improving antibiotic use/stewardship. CDC said the most important action needed to greatly slow the development and spread of antibiotic-resistant infections is to change the way antibiotics are used, which involves the concept of antibiotic stewardship — always using antibiotics appropriately and safely, choosing the right antibiotics and administering them in the right way in every case.
4. Developing drugs and diagnostic tests. Because antibiotic resistance occurs as part of a natural process in which bacteria evolve, it can be slowed but not completely stopped, CDC said. Therefore, new antibiotics always will be needed to keep up with resistant bacteria, as will new tests to track the development of resistance.
The full report is available at www.cdc.gov/drugresistance/threat-report-2013.
The Animal Health Institute (AHI) noted that the CDC report is "consistent with what research has shown for a long time: The largest antibiotic resistance threats are not connected to the use of antibiotics to keep food animals healthy."
Of the 18 specific antibiotic resistance threats discussed in the report, AHI said only two have possible connections to antibiotic use in food animals.
The report also provides support for FDA's policy of phasing out growth promotion uses of medically important antibiotics and phasing in veterinary oversight, which AHI has supported and on which companies are currently working with FDA on implementation.
Fewer MRSA cases
An estimated 30,800 fewer invasive methicillin-resistant Staphylococcus aureus (MRSA) infections occurred in the U.S. in 2011 compared to 2005, according to a study by Dr. Raymund Dantes and colleagues at CDC.
The researchers estimated that 80,461 invasive MRSA infections occurred nationally in 2011. Of those, 48,353 were health care-associated community-onset (HACO) infections, 14,156 were hospital-onset infections and 16,560 were community-associated infections, according to the results published Sept. 16 in the Journal of the American Medical Assn. (JAMA).
Since 2005, national estimated incidence rates have decreased 27.7% for HACO infections, 54.2% for hospital-onset infections and 5.0% for community-onset infections.
However, a separate group reported in the Sept. 16 issue of JAMA that high exposure to swine manure spread in crop fields and proximity to high-density swine livestock operations appeared to be associated with an increased risk of MRSA.
The study, conducted by the Johns Hopkins Bloomberg School of Public Health, focused on 1,539 patients with community-associated MRSA, 1,335 with health care-associated MRSA and 2,895 with skin/soft tissue infections (SSTI), along with 2,914 control patients without MRSA infections who were cared for through a single health care system in Pennsylvania from 2005 to 2010.
The researchers found higher odds of community-associated and health care-associated MRSA and SSTI with higher swine manure exposure in crop fields. High exposure to high-density swine operations also was associated with increased odds of community-associated MRSA and SSTI, the researchers said.