Resistance to Antibiotics: A Global Threat to Public Health

(Disponible en français: La résistance aux antibiotiques : une menace pour la santé publique de portée mondiale)

thinkstockphotos-597969966-antibiotic-resistant-bacteriacropHalting the spread of resistance to antibiotics is becoming one of the major global health challenges of the 21st Century.

The most recent warning came in May 2016, when the Review on Antimicrobial Resistance, commissioned by the UK Government, published its final report and recommendations.

The report estimated that around 700,000 people die each year from drug-resistant diseases. It warned that without measures to stop the spread, this total could hit 10 million a year by 2050, more people than currently die from cancer. Asia and Africa would be most affected. The cost to the global economy could reach $100 trillion US.

Antibiotic resistance refers to the capacity of a bacterial strain to survive exposure to an antibiotic. The emergence of antibiotic resistance is easily explained and not unexpected. However, the manner in which people have used, and misused, antibiotics has accelerated the pace of its development.

The detection of more and more disease-causing bacteria that are resistant to any one of the existing antibiotics, sometimes to several antibiotics, presents a serious public health threat. Some experts suggest that we may be entering a post-antibiotic era, should most bacterial infections become resistant to multiple antibiotics.

This HillNote provides information about the urgency of the problem and describes efforts underway to mitigate the threat. (The term “antimicrobial”, which is used often in the literature referenced in this Note, refers to substances that kill any micro-organism such as viruses and fungi, not just bacteria).

Figure 1: Timeline of Antibiotic Discovery and Emergence of Resistance

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Source: Public Health England, “Guidance – Health Matters: Antimicrobial Resistance,” 10 December 2015

Misuse of antibiotics has accelerated the challenge

Different types of antibiotic misuse have accelerated antibiotic resistance. These include: over-prescribing by doctors; failure to complete the course of antibiotics as prescribed; and the medical and non-medical use of antibiotics in agriculture.

In fact, according to a 2013 report by the Public Health Agency of Canada, more antibiotics are used in the agricultural sector than by people. About two-thirds of the antibiotics used in agriculture (in food-producing animals) are also used to fight bacterial infections in people; only one-third of the antibiotics used in animals are for veterinary use only.

Antibiotics have three uses in agricultural animals: treatment of infection, prevention of infection, and growth promotion. Preventing infection and promoting growth both require widespread distribution of antibiotics to animals, greatly increasing the chance of resistance. Use of antibiotics as growth promoters is controversial and has been prohibited in the European Union since 2006.

To curb agricultural use, the Government of Canada announced in 2014 that it would no longer allow growth promoter claims on antibiotics and that it would improve veterinary oversight of antimicrobial use in food-producing animals.

Figure 2: Where Antibiotics are Used

The concern to public health

As disease-causing bacteria develop resistance to multiple antibiotics, there is greater reliance on newer, more expensive drugs to treat infections. The newer drugs are never the first line of treatment, not only because of cost, but rather as an attempt to slow down the appearance of resistant bacterial strains. However, resistance to the newer drugs will inevitably appear as well.

Public health officials have long feared the appearance of bacterial strains resistant to multiple antibiotics; regrettably, such strains have begun to emerge. For example, in 2016, a bacterial strain that is resistant to colistin, an antibiotic of last resort, was isolated from a woman in the United States. The bacteria had been isolated for the first time in China in 2015.

Vulnerable populations, such as the elderly, are particularly at risk. Such subpopulations may not be strong enough to survive multiple rounds of antibiotics in an attempt to find one that can successfully fight a resistant infection. Without effective antibiotic treatments, infections that are currently considered treatable could once again be fatal, as they were before the advent of antibiotics.

Figure 3: Projected Global Mortality attributable to Antimicrobial Resistance in 2050

Source: The Review on Antimicrobial Resistance, “Antimicrobial Resistance – Tackling a Crisis for the Health and Wealth of Nations,” December 2014.

Source: The Review on Antimicrobial Resistance, “Antimicrobial Resistance – Tackling a Crisis for the Health and Wealth of Nations,” December 2014.

Canadian and global efforts to combat antimicrobial resistance

According to a 2013 report on infectious disease, the rate of prescriptions written for antimicrobials in Canada since 2006 has declined. However, the report also highlighted the emergence of drug resistant microorganisms and the lack of development of new drugs.

Figure 4: Approvals of New Antibiotics by the U.S. Food and Drug Administration between 1983 and 2011

The Government of Canada announced in 2015 that it had invested $143 million in research related to antimicrobial resistance since 2006. The Canadian Institutes of Health Research lists a number of projects under its Antimicrobial Resistance Initiatives. These projects include a $13-million investment in the Novel Alternatives to Antimicrobials Initiative and $6 million in the Joint Programming Initiative on Antimicrobial Resistance, a joint venture with 18 other countries.

On 21 September 2016, UN member states agreed by acclamation to each develop and adopt a national action plan to combat antimicrobial resistance. In addition, the national action plans would have to comply with the parameters outlined by the World Health Organization in its Global Action Plan on Antimicrobial Resistance (2015).

The WHO maintains a library of national plans, in which Canada has participated since 2014. The Government of Canada released a framework in 2014 and an action plan in 2015 to address antimicrobial resistance. The action plan focuses on three areas for action:

  • Surveillance of antimicrobial use and detection of antimicrobial resistance;
  • Stewardship to prevent infections and reduce the use and misuse of antibiotics among humans, as well as in the agricultural sector; and,
  • Investments in innovation to develop new antimicrobials.

Author: Sonya Norris, Library of Parliament