The recently published ‘Longevity Bulletin on Antimicrobial Resistance’ by the Institute and Faculty of Actuaries (IFoA), UK, highlights the social and economic impact of antimicrobial resistance on society in the next decade.
According to Professor Dame Sally Davies, Chief Medical Officer for England, an estimated 50,000 deaths per year have been reported in both Europe and the US, by the World Health Organization (WHO) as a result of antimicrobial resistance. Additionally, by 2050, an estimated 10 million deaths are expected to occur as a result of drug-resistant infections in the Western world.
As a whole, antimicrobial resistance will lead to higher mortality, increased hospital stays and higher treatment costs. Increased mortality due to antimicrobial resistance is also expected to leave an impact on global GDP, with a predicted reduction of 2-3.5% by 2050. All of these effects will cost the world economy up to £66 trillion in the next 35 years. Centers for Disease Control and Prevention (CDC) has estimated that currently more than 23,000 US citizens die per year as a result of having developed antimicrobial resistance.
Antibiotics are undeniably one of the most revolutionary therapeutic discoveries in medical sciences. Treatment with antibiotics has saved countless lives. Since the conception of such drugs, mortality and morbidity from bacterial infections and diseases has reduced greatly.
Unfortunately, these drugs have been misused due to irrelevant prescriptions, and as a result, serious consequences are estimated for the world economy and life expectancy in general.
According to the Global Risk Register, antimicrobial resistance is a problem which deserves a place right next to climate change and terrorism. The class of antibiotics being used today was discovered back in 1987, and since then no new batch has been synthesized for safe human use.
The number of bacteria able to survive or withstand antibiotics has been increasing, causing a problem for doctors since they cannot effectively treat patients from infections anymore. Such a scenario indicates a ‘post-antibiotic era’ reminiscent of the era when such drugs were non-existent and common infections were fatal. Even though experts are working towards stopping antimicrobial resistance, the widespread use of drugs in the human, animal and agriculture sectors is making it hard.
Antimicrobial resistance is a natural evolutionary phenomenon, which cannot be stopped. Bacteria can develop drug resistant genes and transfer them to the next generation through binary fission i.e., a process where the bacterial cells divide into two. In conclusion, the more humans use antibiotics, the more the bacteria evolve.
Bacteria are everywhere and are constantly reproducing e.g., E Coli doubles every 20 minutes.
Mutations randomly take place in a bacterium’s DNA and such mutations have developed resistance against several types of antibiotic drugs in different bacteria. Antibiotics kill a bacterium by entering the organism, but if the bacterium prevents them entering, the drug becomes useless. Resistant bacteria have now developed pumps and enzymes which act against the drug.
Antimicrobial resistance has taken on the form of a grave problem as today bacteria are developing resistance towards an increasing number of drugs, with some even becoming pan-resistant i.e., resistant to every antibiotic treatment for that infection, including last-resort therapies. It is feared that the frequency of such infections will rise.
Experts dealing with the problem of antimicrobial resistance are endorsing the use of ‘good stewardship’ around the world – the responsible use of antibiotic prescription by doctors and healthcare professionals, prescribing them only when they are absolutely necessary.
Similarly, the Longitude Prize was launched as a measure to promote the use of more efficient diagnostic tests of infections. In short, antibiotics should only be given or taken when it is absolutely necessary and they should never be prescribed for trivial conditions such as colds or flu, which are caused by viruses. A more effective diagnosis of diseases can use definite plans of actions in treatment and prevent the misuse of antibiotic drugs.
Currently, in order to combat antimicrobial resistance, a complete shift in public perception and medical use of antibiotics is required. Behavioral intervention was seen in Aberdeen, Scotland, where the prevalence of methicillin-resistant staphylococcus aureus (MRSA) was reduced by 50% using a model of improved stewardship. The results indicated that the safeguard of drugs through proper education, infection control, and the prevention of inappropriate treatment can show substantial outcomes.
The National Health Services (NHS) is planning to launch these principles through a national incentive-based initiative in 2016. The plan will work towards preventing irrelevant prescriptions on a global scale to avoid potential morbidity and mortality due to infections, in the coming future.
Progress on new drugs and vaccines is underway but it will take several years before they can be safely used by the masses. For the time being, antimicrobial resistance is growing faster than the creation of new antimicrobial drugs, therefore the intervention steps are of utmost importance. It should be noted that synthesizing new antibiotics is an expensive and time consuming process with only 3 out of the 41 antibiotics in the research and development phase currently showing promising results.
If these drugs are successfully created, they will have the potential to fight the majority of resistant bacteria. However, realistically speaking, these drugs will be a long time in coming. In a best case scenario, only 1 out of 5 drugs reaching the initial human testing phase, will receive approval for public use.
As of September 2015, the only two new classes of antibiotics in clinical development with the potential to treat serious bacterial infections include Texiobactin and Brilacidin. Teixobactin has the ability to work towards gram-positive bacteria by binding to its cell wall. In-vitro and animal model studies have shown action against antibiotic resistant bacteria including tuberculosis (TB), but human trials are still waiting.
On the other hand, we have Brilacidin, which is the ‘first of a completely new class of antibiotics called ‘defensin-mimetics’, meaning that they are designed from natural human immune proteins and are presently in phase 2 of clinical trials. The mode of action of such proteins can reduce the risk of bacterial resistance by an incredible breadth.
One of the things the Longevity Bulletin concluded was that antimicrobial resistance will leave a ‘material impact on expected medium term mortality and longevity improvements’ and that more modeling needs ‘to be done in a transparent way to allow actuaries to incorporate their own views and to reflect the circumstances of their particular countries’.
Basically, antimicrobial resistance will leave behind substantial effects on expected human survival after contracting infections in the coming years. The models required to deal with the prescription policies need to have more clarity and should be locally designed in accordance with the requirement of different areas.
“The war against microbes is a war against Darwinian evolution — the point is not to win but to stay ahead,” said Dame Sally Davies. “The situation is worrying and challenging but by no means hopeless.”
Numerous alternative approaches are also being examined as potential replacements of antimicrobial drugs. Such methods range from deriving antibacterial peptides from amphibians, reptiles and special viruses to gene-editing, using copper or silver to induce bacterial ‘suicide’.
Another promising alternative method which can reduce antibiotic medicine use is the employment of surgihoney reactive oxygen (SHRO) to heal wounds and control infections. The method has been outlined by Matthew Dryden in a new study which involves using small amounts of ‘reactive oxygen (RO), or single oxygen atoms, via the formation of hydrogen peroxide’ to kill invading pathogenic microorganisms.
“Potential pharmaceutical pipeline developments are few, so perhaps with attention now turning toward alternative approaches, changes in prescribing policy may be the answer to this disquieting problem,” said Dame Sally Davies.