Alfred DeMaria: The most important source of infection with resistant organisms in people is other people. While antimicrobial resistance may, as would be expected, emerge in an organism colonizing or infecting an individual being treated with an antimicrobial agent, more often people acquire resistant organisms from others or a contaminated environment.
The opportunities for such exposure were always higher in healthcare settings, with juxtaposition of vulnerable patients and high utilization of antibiotics. At one time, multidrug-resistant organisms were mostly a problem in acute-care hospitals, but now because of the broad spectrum of care settings and movement of patients, the problem is wider, inclusive of home, transitional, rehabilitation, and long-term care settings.
Brandi Limbago: Most infections with antibiotic-resistant bacteria happen in healthcare settings, due to the selective pressure created by high antibiotic use and the presence of both drug-resistant donor organisms and very susceptible patients. Colonized and infected patients often transition between hospitals and long-term care facilities, which can facilitate the spread of resistant organisms among many facilities in a region.
This is one reason that it is important to have situational awareness of the extent of the antibiotic resistance in a given region. How do you interpret the 2 studies that come to apparently different conclusions about the value of interventions to prevent transmission of MRSA in hospitalized patients [N Engl J Med ; Huskins et al.
David Hooper: The reasons for the differences in the outcomes of these 2 studies are likely multiple, including differences in trial design, compliance with the planned intervention, and overlapping interventions, as discussed in a editorial in the New England Journal of Medicine by Richard Platt. As tests of the effectiveness of broad surveillance of patients for carriage of MRSA, these studies leave unresolved the controversy about the value in improved outcomes balanced against operational and other costs of such a surveillance strategy and highlight the importance of future evaluations.
The effectiveness of the several interventions in the study by Jain et al. In my experience related to a program resulting in substantial and sustained improvements in hand hygiene before and after patient contact that were followed by major reductions in hospital acquisition of MRSA, I think system-wide approaches with buy-in and participation of a broad range of care providers and senior management are particularly important for interventions to be effective in complex healthcare environments.
Screening incoming patients is key to prevent patients from shedding drug-resistant bacteria on bedrails, wheelchairs, floors, or wherever they go. So why did the 2 studies yield such different results?
The study by Huskins et al. Patients were cultured within 2 days of admission, allowing plenty of time for colonized patients to shed bacteria. Worse still, the mean time from taking the culture to reporting the result was 5. For the majority of patients, their ICU stay was more than half over. Had patients been preemptively isolated until their culture results came back, that problem could have been avoided. Delay can defeat the purposes of screening.
But the study had the same flaw. The study by Jain et al. An astounding Therefore, screening identified many more carriers than it would in a more typical hospital setting. O'Brien: The study by Huskins et al. The discussion thoughtfully points out possible reasons for the study's failure to find an expected reduction in rates of colonization for the more stringent precautions, including slow culture turnaround time that extended the unprotected time before initiation of precautions.
The substantial reduction in infection rate reported would be exemplary—even if the antecedent rate were higher than average. Do you think that hospitals should be required to report their rates of hospital-acquired infections by antibiotic-resistant bacteria to public health authorities?
Should this information be made publicly available with identification of the specific hospitals? Betsy McCaughey: Yes. Secrecy allowed the problem of hospital infections to fester for too long. The Committee to Reduce Infection Deaths has aggressively campaigned for disclosure of hospital infection rates. There is no reason to restrict reporting to drug-resistant infections. Reporting should include Clostridium difficile, for example. David Hooper: To improve the quality of patient care, it is necessary to collect and analyze data and ultimately to hold healthcare workers and institutions accountable for their practices.
Reporting can be an important component of accountability, and reports are most easily interpreted when they relate to compliance with established procedures that should be consistently followed.
Reporting of outcomes such as resistant infections, however, is more complex because of variation in patient populations and the complexity of care provided that affect risks of prior carriage and new acquisition of resistant bacteria and the risks of hospital-acquired infections from them. Standardized reporting of compliance with best practices to public health authorities and to the public is important.
Outcomes reporting has a greater potential for misinterpretation because of modifying factors not necessarily under the control of the institution and should be directed to public health authorities, who are in a position to understand and evaluate the complexities.
Public reporting of rates of antibiotic-resistant bacteria, however, has considerable risk of misinterpretation and unintended consequences that could impede the common goal of improving quality of patient care. Alfred DeMaria: In many states, certain healthcare-associated infections are mandated for public reporting by facility, with data on infecting organisms. The Centers for Medicare and Medicaid Services require public reporting of a number of quality indicators, including infections, as a condition for participation and enhanced financial compensation.
Such transparency can be a stimulus to enhanced quality improvement. States have attempted to do public health and population-based surveillance for antimicrobial-resistant organisms in various ways. This is difficult because of the multiple organisms that cause infection, the multiple antibiotics used in testing, and the multiple mechanisms of resistance. As electronic support for such surveillance becomes more robust, the opportunity for antimicrobial-resistance surveillance will expand, and useful and actionable information may be available for public health measures.
Alfred DeMaria: Scientific and medical organizations have advocated for decades for a ban on use of antibiotics for growth promotion in animals. Resistant organisms do emerge under nontherapeutic use of antibiotics in animals, but the contribution of this source of antibiotic resistance in human pathogens remains controversial.
The FDA came close to banning penicillin and tetracycline agents in animal feed at the end of , but backed off and closed hearings that had opened in They proposed banning nontherapeutic cephalosporins in early However, vaccine development is a difficult enterprise and it can take a long time in any given case. Sometimes it has failed despite many years of work. Bacteriophages —naturally occurring viruses that attack specific bacteria—have sometimes been mentioned as possible tools.
Although they were discovered in the early 20th century, their clinical use has so far been limited to some efforts in Russia, [the Republic of] Georgia and Poland. This is partly because they are large biological agents, and delivering the phage to the appropriate target is not as straightforward as administering a small-molecule antibiotic.
Phages and bacteria can also mutate, rendering them ineffective. However, it is possible that future research may pave the way for greater use of phages to treat bacterial infections. Are governments and the public beginning to understand the problem with resistant bacteria and do something about it?
I think so. Of course, when resistance becomes a huge problem and starts affecting the middle class and the rich, there will be an outcry. But I think things are already changing. In India, for instance, I see a lot of opinions for stricter regulations of antibiotics and for their better use. Measures like public health and hygiene will take a long time.
Do you think the production of drugs should be funded by governments or by private companies, as it is mostly the case today? I personally believe that for certain things the private enterprise model is not going to work. It costs a huge amount of money to develop a new drug. And that itself limits the number of patients who can take this medicine—and that limits your income. So antibiotics by their nature are not going to be the same class of moneymaker.
So I think that governments really need to get involved in the development of new antibiotics. They have to think of this as something generally good for society, the same reason that governments fund education, roads, police, defense and so on.
This is one case where governments need to act. Already a subscriber? Sign in. Thanks for reading Scientific American. Create your free account or Sign in to continue. See Subscription Options. However, some bacteria have become resistant to commonly used antibiotics. Antibiotic resistant bacteria are bacteria that are not controlled or killed by antibiotics.
They are able to survive and even multiply in the presence of an antibiotic. Most infection-causing bacteria can become resistant to at least some antibiotics.
Bacteria that are resistant to many antibiotics are known as multi-resistant organisms MRO. Antibiotic resistance is a serious public health problem. It can be prevented by minimising unnecessary prescribing and overprescribing of antibiotics, the correct use of prescribed antibiotics, and good hygiene and infection control. Some bacteria are naturally resistant to some antibiotics.
For example, benzyl penicillin has very little effect on most organisms found in the human digestive system gut. Some bacteria have developed resistance to antibiotics that were once commonly used to treat them.
In the past, these infections were usually controlled by penicillin. The most serious concern with antibiotic resistance is that some bacteria have become resistant to almost all of the easily available antibiotics. These bacteria are able to cause serious disease and this is a major public health problem. Important examples are:. Standard precautions in hospitals are work practices that provide a basic level of infection control for the care of all people, regardless of their diagnosis or presumed infection status.
These precautions should be followed in all hospitals and healthcare facilities and include:. Implementing standard precautions minimises the risk of transmission of infection from person to person, even in high-risk situations. Additional precautions are used when caring for people who are known or suspected to be infected or colonised with highly infectious pathogens micro-organisms that cause disease.
Additional precautions are tailored to the particular pathogen and route of transmission. Additional precautions may include:. Antibiotic resistant bacteria can also be passed from person to person within the community. This is becoming more common. Ways to prevent transmission of organisms, including antibiotic resistant bacteria, are:.
This page has been produced in consultation with and approved by:. Anthrax is a rare but potentially fatal bacterial disease that occasionally infects humans.
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