Antibiotic resistance: A global threat to public health

Antibiotic resistance is a growing concern that threatens the effective treatment of infectious diseases.[1] A recent report published by the World Health Organization on the global surveillance of antimicrobial resistance demonstrates the severity of this issue and calls for concerted action among all government sectors and society to mitigate antimicrobial resistance.[1] The report is available at www.who.int/mediacentre/news/releases/2014/amr-report/en.

To evaluate the scope of the issue, resistance data of selected bacteria from 114 countries were obtained and the findings were alarming (see Table). Of note, antimicrobial resistance associated with common infections (e.g., urinary tract infections, pneumonia, and bloodstream infections) has reached a level where standard treatment most readily available in many parts of the world has been rendered ineffective. In addition, antibiotic usage in nonhumans adds further complexity to this process due to spread of resistance genes across species, and it should be carefully monitored.[1] Resistance to last-line therapy, such as carbapenems, and a lack of new therapeutics adds to the urgency of the current global situation.[1] Moreover, systematic reviews show that patients infected with antibiotic resistant bacteria are not only at risk of poorer health outcomes but also consume more health resources (e.g., lengthier hospital stays, ICU admission, or use of long-term care facilities).[1]

This first report on global antimicrobial resistance noted a severe lack in coordination of efforts in global surveillance and information-sharing systems. Moreover, international standardization on methodology was recommended to increase the comparability and quality of data collected to support a more accurate reflection of the impact of resistance in order to inform policies and prioritize resource distribution. 

The high proportion (50%) of resistance among E. coli (five of six WHO regions) and K. pneumoniae (six of six WHO regions) to third-generation cephalosporins is illustrated in the Table. While more options are available for simple cystitis, serious bloodstream infections by these isolates are driving increased use of carbapenems at costs that are prohibitive in resource-constrained settings.[1] The use of carbapenems may also accelerate the development of carbapenem resistance, a characteristic identified in up to 54% of reported K. pneumoniae isolates.[1]

Community-associated MRSA is now highly prevalent in both hospital and community settings, requiring second-line treatment with glycopeptides, linezolid, or daptomycin.[1,2] These agents require careful monitoring for adverse effects and have increased treatment costs. Among countries providing S. aureus data, 44% reported MRSA (in proportions of 20% or greater) among their isolates.[1]

S. pneumoniae is the leading cause of community-acquired pneumonia in children under 5 years of age, with an estimated 826 000 deaths.[1] A third of the countries contributing data documented penicillin resistance in over 50% of isolates.

Resistance patterns in BC reflect the international trends; however, our results are mixed.[2] According to BC Biomedical Laboratories (now part of LifeLabs Medical Laboratory Services), resistance of E. coli to ciprofloxacin increased between 2007 and 2010 and is reported to be at 25.3% in 2012.[2]

The proportion of S. pneumoniae nonsusceptible to penicillin in BC has stabilized since 2010 and was reported to be at 17.2% in 2012.[2] MRSA has fluctuated between 16% and 30% of S. aureus isolates between 2007 and 2012. However, the overall trend from all data sources shows that the proportion of MRSA has decreased slightly.[2]

Although antibiotic resistance is a natural phenomenon, the selective pressure posed by the inappropriate use of antibiotics has exacerbated the situation. Not only does the misuse of antibiotics contribute to the emergence, persistence, and spread of multiresistant bacteria, it may also result in side effects and drug interactions.[1] BC physicians are adopting better prescribing practices using aids such as the Bugs & Drugs guide.[3] By continuing to move toward sounder practice in antibiotic therapy, we will go a long way to preserving the benefits of antibiotic therapy for British Columbians.
—Sophie Y. Wang, BSc
—Diana George, MSc
—Dale Purych, MD, FRCPC
—David M. Patrick, MD, FRCPC, MHSc

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This article is the opinion of the BC Centre for Disease Control and has not been peer reviewed by the BCMJ Editorial Board

References

1.    World Health Organization. Antimicrobial resistance: Global report on surveillance. Geneva: Switzerland; 2014.
2.    Hachborn D, Patrick D. BC Centre for Disease Control. Antimicrobial resistance trend in the province of British Columbia. Vancouver, BC: Centre for Disease Control; 2012.
3.    Blondel-Hill E, Fryters F. Bugs & Drugs 2012. Alberta Health Services; 2012. www.bugsanddrugs.ca.