Antimicrobial resistance (AMR) has emerged as one of the principal public health problems of the 21st century. This has resulted in a public health crisis of international concern, which threatens the practice of modern medicine, animal health and food security. Antibacterial and antifungal use in animal and agricultural industries aggravates selective pressure on microbes. A One Health approach is urgently required. The burden of AMR is difficult to quantify in some regions of the world because enhanced surveillance requires personnel, equipment and financial resources that are not always available. However the impact of AMR worldwide is significant, both in economic terms, and clinical morbidity and mortality because it may:
- lead to some infections becoming untreatable,
- lead to inappropriate empirical treatment in critically ill patients where an appropriate and prompt treatment is mandatory,
- increase length of hospital stay, morbidity, mortality and cost, and
- make necessary alternative antimicrobials which are more toxic, less effective, or more expensive.
The global nature of AMR calls for a global response, both in the geographic sense and across the whole range of sectors involved. Emergence of AMR, combined with very few new antimicrobial agents in the drug development pipeline, indicates that awareness and understanding of antimicrobial resistance is necessary.
The World Health Organization (WHO) endorsed a global action plan to tackle antimicrobial resistance. It sets out five strategic objectives:
- to improve awareness and understanding of antimicrobial resistance,
- to strengthen knowledge through surveillance and research,
- to reduce the incidence of infection,
- to optimize the use of antimicrobial agents, and
- to develop the economic case for sustainable investment that takes account of the needs of all countries, and increase investment in new medicines, diagnostic tools, vaccines and other interventions.
The substantial problem of antimicrobial resistance is especially relevant to antibiotic resistance (ABR), although antifungal resistance is increasing at an alarming rate. Although the phenomenon of ABR can be attributed to many factors, there is a well-established relationship between antibiotic prescribing practices and the emergence of resistant bacteria.
ABR prevalence has increased alarmingly over the past decades. In 2008 the acronym “ESKAPE” pathogens which refers to Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species was proposed to highlight those pathogens where amr is of particular concern and to emphasize which bacteria increasingly “escape” the effects of antibiotics. These organisms are increasingly multi-drug- (MDR), extensive-drug- (XDR) and pan-drug- resistant (PDR) and this process is accelerating globally.
Antibiotics can be life-saving when treating bacterial infections but are often used inappropriately, specifically when unnecessary or when administered for excessive durations or without consideration of pharmacokinetic principles. Large variations in antibiotic consumption exist between countries and whilst excessive use remains a major problem in some areas of the world, elsewhere there is lack of access to many antimicrobial agents. ABR is a natural phenomenon that occurs as microbes evolve. However, human activities have accelerated the pace at which bacteria develop and disseminate resistance. Inappropriate use of antibiotics in humans and food-producing animals, as well as poor infection prevention and control practices, contribute to the development and spread of ABR. Appropriate use of antibiotics is an integral part of good clinical practice. This attitude maximizes the utility and therapeutic efficacy of treatment, and minimizes the risks associated with emerging infections and the selection of resistant pathogens.
The indiscriminate and excess use of antibiotic drugs appears the most significant factor in the emergence of resistant bacteria in recent years. Clinicians should be aware of their role and responsibility for maintaining the effectiveness of current and future antimicrobials. They can help tackle resistance by:
- enhancing infection prevention and control,
- controlling the source of infection when it is needed,
- prescribing and dispensing antibiotics when they are truly needed, and
- prescribing and dispensing the right antibiotics(s) to treat the illness.
An effective and cost-effective strategy to reduce ABR should involve a multi-faceted approach aimed at optimizing antibiotic use, strengthening surveillance and infection prevention and control, and improving patient and clinician education regarding the appropriate use of antibiotics. Although the current magnitude of the problem and its extent in both the community and the hospital adds to the complexity of any intervention, these are still necessary as healthcare workers play a central role in preventing the emergence and spread of resistance.